Fix non-contiguous program indices

* chore: update type testing setup
* stricter TSConfig
* deduplicate type checking

.editorconfig

@@ -0,0 +1,11 @@
+root = true
+
+[*.js]
+indent_size = 2
+insert_final_newline = true
+trim_trailing_whitespace = true
+
+[*.yml]
+indent_size = 2
+insert_final_newline = true
+trim_trailing_whitespace = true

.git-blame-ignore-revs

@@ -0,0 +1,6 @@
+# Upgrade to Prettier 2.7
+3d228334530860a6e3f99dc10777c84bf22292c1
+# Format markdown files with Prettier
+dfe2eaaf20f0b679d94e5a799757c4394d80f1cc
+# migrate to oxlint and oxfmt
+0c1d00282ca619c3416ad819bdf53c0852b32415

.gitattributes

@@ -0,0 +1,6 @@
+# Handlebars-template fixtures in test cases need deterministic eol
+*.handlebars text eol=lf
+*.hbs text eol=lf
+
+# Lexer files as well
+*.l text eol=lf

.github/ISSUE_TEMPLATE.md

@@ -0,0 +1,9 @@
+Before filing issues, please check the following points first:
+
+- [ ] Please don't open issues for security issues. Instead, file a report at https://www.npmjs.com/advisories/report?package=handlebars
+- [ ] Have a look at https://github.com/handlebars-lang/handlebars.js/blob/master/CONTRIBUTING.md
+- [ ] Read the FAQ at https://github.com/handlebars-lang/handlebars.js/blob/master/FAQ.md
+- [ ] Use the jsfiddle-template at https://jsfiddle.net/4nbwjaqz/4/ to reproduce problems or bugs
+
+This will probably help you to get a solution faster.
+For bugs, it would be great to have a PR with a failing test-case.

.github/PULL_REQUEST_TEMPLATE.md

@@ -0,0 +1,12 @@
+Before creating a pull-request, please check https://github.com/handlebars-lang/handlebars.js/blob/master/CONTRIBUTING.md first.
+
+Generally we like to see pull requests that
+
+- [ ] Please don't start pull requests for security issues. Instead, file a report at https://www.npmjs.com/advisories/report?package=handlebars
+- [ ] Maintain the existing code style
+- [ ] Are focused on a single change (i.e. avoid large refactoring or style adjustments in untouched code if not the primary goal of the pull request)
+- [ ] Have good commit messages
+- [ ] Have tests
+- [ ] Have the [typings](https://www.typescriptlang.org/docs/handbook/declaration-files/introduction.html) (types/index.d.ts) updated on every API change. If you need help, updating those, please mention that in the PR description.
+- [ ] Don't significantly decrease the current code coverage (see coverage/lcov-report/index.html)
+- [ ] Please target the `master` branch in the PR.

.github/dependabot.yml

@@ -0,0 +1,9 @@
+version: 2
+updates:
+  - package-ecosystem: npm
+    directory: '/'
+    open-pull-requests-limit: 0
+    schedule:
+      interval: weekly
+    allow:
+      - dependency-type: production

.github/workflows/ci.yml

@@ -0,0 +1,91 @@
+name: CI
+
+on:
+  push:
+    branches:
+      - master
+  pull_request: {}
+
+jobs:
+  lint:
+    name: Lint
+    runs-on: 'ubuntu-latest'
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v6
+
+      - name: Setup Node.js
+        uses: actions/setup-node@v6
+        with:
+          node-version: '24'
+
+      - name: Install dependencies
+        run: npm ci
+
+      - name: Lint
+        run: npm run lint
+
+  test:
+    name: Test (Node)
+    runs-on: ${{ matrix.operating-system }}
+    strategy:
+      fail-fast: false
+      matrix:
+        operating-system: ['ubuntu-latest', 'windows-latest']
+        # https://nodejs.org/en/about/releases/
+        node-version: ['20', '22', '24']
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v6
+        with:
+          submodules: true
+
+      - name: Setup Node.js
+        uses: actions/setup-node@v6
+        with:
+          node-version: ${{ matrix.node-version }}
+
+      - name: Install dependencies
+        run: npm ci
+
+      - name: Test
+        run: npm run test
+
+      - name: Test (Publish)
+        if: matrix.node-version != '20'
+        run: npx vitest run --project publish
+
+      - name: Test (Integration)
+        if: matrix.operating-system == 'ubuntu-latest'
+        run: npm run test:integration
+
+  browser:
+    name: Test (Browser)
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v6
+        with:
+          submodules: true
+
+      - name: Setup Node.js
+        uses: actions/setup-node@v6
+        with:
+          node-version: '24'
+
+      - name: Install dependencies
+        run: npm ci
+
+      - name: Install Playwright
+        run: |
+          npx playwright install-deps
+          npx playwright install
+
+      - name: Build
+        run: npm run build
+
+      - name: Test
+        run: |
+          npm run test:browser-smoke
+          npm run test:browser

.github/workflows/release.yml

@@ -0,0 +1,39 @@
+name: Release
+
+on:
+  workflow_dispatch:
+  push:
+    branches:
+      - master
+    tags:
+      - '*'
+
+jobs:
+  publish-aws-s3:
+    name: Publish to AWS S3
+    runs-on: 'ubuntu-latest'
+    environment: 'builds.handlebarsjs.com.s3.amazonaws.com'
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v6
+        with:
+          submodules: true
+
+      - name: Setup Node.js
+        uses: actions/setup-node@v6
+        with:
+          node-version: '24'
+
+      - name: Install dependencies
+        run: npm ci
+
+      - name: Publish
+        run: |
+          git config --global user.email "release@handlebarsjs.com"
+          git config --global user.name "handlebars-lang"
+          npm run publish:aws
+        env:
+          S3_BUCKET_NAME: 'builds.handlebarsjs.com'
+          S3_REGION: 'us-east-1'
+          S3_ACCESS_KEY_ID: ${{ secrets.S3_ACCESS_KEY_ID }}
+          S3_SECRET_ACCESS_KEY: ${{ secrets.S3_SECRET_ACCESS_KEY }}

.gitignore

@@ -1,11 +1,19 @@
-vendor
 .rvmrc
 .DS_Store
-lib/handlebars/compiler/parser.js
-/dist/
 /tmp/
-node_modules
 *.sublime-project
 *.sublime-workspace
 npm-debug.log
-sauce_connect.log*
+.idea
+/yarn-error.log
+/yarn.lock
+node_modules
+/handlebars-release.tgz
+.nyc_output
+
+# Generated files
+/coverage/
+/dist/
+/tests/bench/results/
+/tests/integration/*/dist/
+/spec/tmp/*

.gitmodules

@@ -0,0 +1,3 @@
+[submodule "spec/mustache"]
+	path = spec/mustache
+	url = https://github.com/mustache/spec.git

.jshintrc

@@ -1,51 +0,0 @@
-{
-    "predef": [
-        "console",
-        "require",
-        "suite",
-        "equal",
-        "equals",
-        "test",
-        "testBoth",
-        "raises",
-        "deepEqual",
-        "start",
-        "stop",
-        "ok",
-        "strictEqual",
-        "module",
-        "define",
-
-        "describe",
-        "it",
-        "afterEach",
-        "beforeEach"
-    ],
-
-    "node" : true,
-    "browser" : true,
-    "esnext": true,
-
-    "boss" : true,
-    "curly": false,
-    "debug": false,
-    "devel": false,
-    "eqeqeq": false,
-    "eqnull": true,
-    "evil": true,
-    "forin": false,
-    "immed": false,
-    "laxbreak": true,
-    "newcap": true,
-    "noarg": true,
-    "noempty": false,
-    "nonew": false,
-    "nomen": false,
-    "onevar": false,
-    "plusplus": false,
-    "regexp": false,
-    "undef": true,
-    "sub": true,
-    "strict": false,
-    "white": false
-}

.npmignore

@@ -1,23 +0,0 @@
-.DS_Store
-.gitignore
-.rvmrc
-.jshintrc
-.travis.yml
-.rspec
-Gemfile
-Gemfile.lock
-Rakefile
-Gruntfile.js
-*.gemspec
-*.nuspec
-bench/*
-configurations/*
-components/*
-dist/cdnjs/*
-dist/components/*
-spec/*
-src/*
-tasks/*
-tmp/*
-publish/*
-vendor/*

.oxfmtrc.json

@@ -0,0 +1,28 @@
+{
+  "$schema": "https://raw.githubusercontent.com/nicolo-ribaudo/oxfmt-config-schema/refs/heads/main/schema.json",
+  "singleQuote": true,
+  "tabWidth": 2,
+  "semi": true,
+  "trailingComma": "es5",
+  "printWidth": 80,
+  "ignorePatterns": [
+    ".rvmrc",
+    ".DS_Store",
+    "/tmp/",
+    "*.sublime-project",
+    "*.sublime-workspace",
+    "npm-debug.log",
+    "sauce_connect.log*",
+    ".idea",
+    "yarn-error.log",
+    "/coverage/",
+    ".nyc_output/",
+    "/dist/",
+    "/tests/integration/*/dist/",
+    "/spec/expected/",
+    "/spec/mustache",
+    "/spec/vendor",
+    "*.handlebars",
+    "*.hbs"
+  ]
+}

.oxlintrc.json

@@ -0,0 +1,150 @@
+{
+  "$schema": "https://raw.githubusercontent.com/oxc-project/oxc/main/npm/oxlint/configuration_schema.json",
+  "plugins": ["eslint", "typescript", "unicorn", "oxc", "node", "vitest"],
+  "categories": {
+    "correctness": "error"
+  },
+  "rules": {
+    "no-console": "warn",
+    "no-func-assign": "off",
+    "no-sparse-arrays": "off",
+
+    "default-case": "warn",
+    "guard-for-in": "warn",
+    "no-alert": "error",
+    "no-caller": "error",
+    "no-div-regex": "warn",
+    "no-eval": "error",
+    "no-extend-native": "error",
+    "no-extra-bind": "error",
+    "no-implied-eval": "error",
+    "no-iterator": "error",
+    "no-labels": "error",
+    "no-lone-blocks": "error",
+    "no-loop-func": "error",
+    "no-multi-str": "warn",
+    "no-global-assign": "error",
+    "no-new": "error",
+    "no-new-func": "error",
+    "no-new-wrappers": "error",
+    "no-proto": "error",
+    "no-return-assign": "error",
+    "no-script-url": "error",
+    "no-self-compare": "error",
+    "no-sequences": "error",
+    "no-throw-literal": "error",
+    "no-unused-expressions": "error",
+    "no-warning-comments": "warn",
+    "no-with": "error",
+    "radix": "error",
+
+    "no-label-var": "error",
+    "no-use-before-define": ["error", { "functions": false }],
+
+    "no-var": "error",
+
+    "node/no-process-env": "error"
+  },
+  "ignorePatterns": [
+    "tmp/",
+    "dist/",
+    "coverage/",
+    ".nyc_output/",
+    "handlebars-release.tgz",
+    "tests/integration/*/dist/",
+    "spec/expected/",
+    "spec/mustache",
+    "spec/vendor",
+    "node_modules",
+    "types/"
+  ],
+  "overrides": [
+    {
+      "files": ["lib/**/*.js"],
+      "env": {
+        "node": false,
+        "browser": true
+      }
+    },
+    {
+      "files": ["spec/**/*.js"],
+      "globals": {
+        "CompilerContext": "readonly",
+        "Handlebars": "writable",
+        "handlebarsEnv": "readonly",
+        "expectTemplate": "readonly",
+        "suite": "readonly",
+        "test": "readonly",
+        "testBoth": "readonly",
+        "raises": "readonly",
+        "deepEqual": "readonly",
+        "start": "readonly",
+        "stop": "readonly",
+        "ok": "readonly",
+        "vi": "readonly",
+        "strictEqual": "readonly",
+        "define": "readonly",
+        "expect": "readonly",
+        "beforeEach": "readonly",
+        "afterEach": "readonly",
+        "describe": "readonly",
+        "it": "readonly"
+      },
+      "rules": {
+        "no-var": "off",
+        "dot-notation": "off",
+        "vitest/no-conditional-tests": "off"
+      }
+    },
+    {
+      "files": ["tasks/**/*.js"],
+      "rules": {
+        "node/no-process-env": "off",
+        "prefer-const": "warn",
+        "dot-notation": "error"
+      }
+    },
+    {
+      "files": ["tasks/tests/**/*.js"],
+      "globals": {
+        "describe": "readonly",
+        "it": "readonly",
+        "expect": "readonly",
+        "beforeEach": "readonly",
+        "afterEach": "readonly",
+        "vi": "readonly"
+      }
+    },
+    {
+      "files": ["tests/bench/**/*.mjs"],
+      "rules": {
+        "no-console": "off"
+      }
+    },
+    {
+      "files": ["tests/integration/multi-nodejs-test/**/*.js"],
+      "rules": {
+        "no-console": "off",
+        "no-var": "off"
+      }
+    },
+    {
+      "files": ["tests/browser/**/*.js"],
+      "env": {
+        "browser": true
+      }
+    },
+    {
+      "files": [
+        "tests/integration/webpack-babel-test/src/**/*.js",
+        "tests/integration/webpack-test/src/**/*.js"
+      ],
+      "env": {
+        "browser": true
+      },
+      "rules": {
+        "no-var": "off"
+      }
+    }
+  ]
+}

.swcrc

@@ -0,0 +1,8 @@
+{
+  "$schema": "https://swc.rs/schema.json",
+  "module": {
+    "type": "commonjs",
+    "importInterop": "swc"
+  },
+  "sourceMaps": "inline"
+}

.travis.yml

@@ -1,23 +0,0 @@
-language: node_js
-before_install:
-- npm install -g grunt-cli
-script:
-- grunt --stack travis
-email:
-  on_failure: change
-  on_success: never
-env:
-  global:
-  - S3_BUCKET_NAME=builds.handlebarsjs.com
-  - secure: ckyEe5dzjdFDjmZ6wIrhGm0CFBEnKq8c1dYptfgVV/Q5/nJFGzu8T0yTjouS/ERxzdT2H327/63VCxhFnLCRHrsh4rlW/rCy4XI3O/0TeMLgFPa4TXkO8359qZ4CB44TBb3NsJyQXNMYdJpPLTCVTMpuiqqkFFOr+6OeggR7ufA=
-  - secure: Nm4AgSfsgNB21kgKrF9Tl7qVZU8YYREhouQunFracTcZZh2NZ2XH5aHuSiXCj88B13Cr/jGbJKsZ4T3QS3wWYtz6lkyVOx3H3iI+TMtqhD9RM3a7A4O+4vVN8IioB2YjhEu0OKjwgX5gp+0uF+pLEi7Hpj6fupD3AbbL5uYcKg8=
-matrix:
-  include:
-  - node_js: '0.10'
-    env:
-    - PUBLISH=true
-    - secure: pLTzghtVll9yGKJI0AaB0uI8GypfWxLTaIB0ZL8//yN3nAEIKMhf/RRilYTsn/rKj2NUa7vt2edYILi3lttOUlCBOwTc9amiRms1W8Lwr/3IdWPeBLvLuH1zNJRm2lBAwU4LBSqaOwhGaxOQr6KHTnWudhNhgOucxpZfvfI/dFw=
-    - secure: yERYCf7AwL11D9uMtacly/THGV8BlzsMmrt+iQVvGA3GaY6QMmfYqf6P6cCH98sH5etd1Y+1e6YrPeMjqI6lyRllT7FptoyOdHulazQe86VQN4sc0EpqMlH088kB7gGjTut9Z+X9ViooT5XEh9WA5jXEI9pXhQJNoIHkWPuwGuY=
-cache:
-  directories:
-  - node_modules

CONTRIBUTING.md

@@ -0,0 +1,123 @@
+# How to Contribute
+
+## Reporting Security Issues
+
+Please refer to our [Security Policy](https://github.com/handlebars-lang/handlebars.js/blob/master/SECURITY.md).
+
+## Reporting Issues
+
+Please refer to our [FAQ](https://github.com/handlebars-lang/handlebars.js/blob/master/FAQ.md) for common issues that people run into.
+
+Should you run into other issues with the project, please don't hesitate to let us know by filing an [issue][issue]!
+
+In general, we are going to ask for an **example** of the problem failing, which can be as simple as a jsfiddle/jsbin/etc. We've put together a jsfiddle **[template][jsfiddle]** to ease this. (We will keep this link up to date as new releases occur, so feel free to check back here).
+
+Pull requests containing only failing tests demonstrating the issue are welcomed and this also helps ensure that your issue won't regress in the future once it's fixed.
+
+Documentation issues on the [handlebarsjs.com](https://handlebarsjs.com) site should be reported on [handlebars-lang/docs](https://github.com/handlebars-lang/docs).
+
+## Branches
+
+- The branch `master` contains the current development version (v5).
+- The branch `4.x` contains the previous stable version. Only critical bugfixes are backported there.
+
+## Pull Requests
+
+We also accept [pull requests][pull-request]!
+
+Generally we like to see pull requests that
+
+- Maintain the existing code style
+- Are focused on a single change (i.e. avoid large refactoring or style adjustments in untouched code if not the primary goal of the pull request)
+- Have [good commit messages](http://tbaggery.com/2008/04/19/a-note-about-git-commit-messages.html)
+- Have tests
+- Don't significantly decrease the current code coverage (see coverage/lcov-report/index.html)
+
+## Building
+
+To build Handlebars.js you'll need Node.js installed.
+
+Before building, you need to make sure that the Git submodule `spec/mustache` is included (i.e. the directory `spec/mustache` should not be empty). To include it, if using Git version 1.6.5 or newer, use `git clone --recursive` rather than `git clone`. Or, if you already cloned without `--recursive`, use `git submodule update --init`.
+
+Project dependencies may be installed via `npm install`.
+
+To build Handlebars.js from scratch, run `npm run build` in the root of the project. That will compile CJS modules via SWC and bundle UMD distributions via rspack, outputting results to the dist/ folder. To run tests, use `npm test`.
+
+If you notice any problems, please report them to the GitHub issue tracker at
+[http://github.com/handlebars-lang/handlebars.js/issues](http://github.com/handlebars-lang/handlebars.js/issues).
+
+## Running Tests
+
+To run tests locally, first install all dependencies.
+
+```sh
+npm install
+```
+
+Clone the mustache specs into the spec/mustache folder.
+
+```sh
+cd spec
+rm -r mustache
+git clone https://github.com/mustache/spec.git mustache
+```
+
+From the root directory, run the tests.
+
+```sh
+npm test
+```
+
+## Linting and Formatting
+
+Handlebars uses `oxlint` for linting, `oxfmt` for formatting, and `eslint` (with `eslint-plugin-compat`) for browser API compatibility checks.
+Committed files are linted and formatted in a pre-commit hook.
+
+You can use the following scripts to make sure that the CI job does not fail:
+
+- **npm run lint** will run all linters and fail on warnings
+- **npm run format** will format all files
+- **npm run check-before-pull-request** will perform all checks that our CI job does, excluding integration tests.
+- **npm run test:integration** will run integration tests (bundler compatibility with webpack, rollup, etc.)
+  These tests only work on Linux.
+
+## Releasing the latest version
+
+Before attempting the release Handlebars, please make sure that you have the following authorizations:
+
+- Push-access to `handlebars-lang/handlebars.js`
+- Publishing rights on npmjs.com for the `handlebars` package
+- Publishing rights on gemfury for the `handlebars-source` package
+- Push-access to the repo for legacy package managers: `components/handlebars`
+- Push-access to the production-repo of the handlebars site: `handlebars-lang/handlebarsjs.com-github-pages`
+
+_When releasing a previous version of Handlebars, please look into the CONTRIBUNG.md in the corresponding branch._
+
+A full release may be completed with the following:
+
+```
+npm ci
+npm run build
+npm publish
+```
+
+After the release, you should check that all places have really been updated. Especially verify that the `latest`-tags
+in those places still point to the latest version
+
+- [The npm-package](https://www.npmjs.com/package/handlebars) (check latest-tag)
+- [The bower package](https://github.com/components/handlebars.js) (check the package.json)
+- [The AWS S3 Bucket](https://s3.amazonaws.com/builds.handlebarsjs.com) (check latest-tag)
+- [RubyGems](https://rubygems.org/gems/handlebars-source)
+
+When everything is OK, the **handlebars site** needs to be updated.
+
+Go to the master branch of the repo [handlebars-lang/docs](https://github.com/handlebars-lang/docs/tree/master)
+and make a minimal change to the README. This will invoke a github-action that redeploys
+the site, fetching the latest version-number from the npm-registry.
+(note that the default-branch of this repo is not the master and regular changes are done
+in the `handlebars-lang/docs`-repo).
+
+[generator-release]: https://github.com/walmartlabs/generator-release
+[pull-request]: https://github.com/handlebars-lang/handlebars.js/pull/new/master
+[issue]: https://github.com/handlebars-lang/handlebars.js/issues/new
+[jsfiddle]: https://jsfiddle.net/4nbwjaqz/4/

FAQ.md

@@ -0,0 +1,54 @@
+# Frequently Asked Questions
+
+## How can I file a bug report:
+
+See our guidelines on [reporting issues](https://github.com/handlebars-lang/handlebars.js/blob/master/CONTRIBUTING.md#reporting-issues).
+
+## Why isn't my Mustache template working?
+
+Handlebars deviates from Mustache slightly on a few behaviors. These variations are documented in our [readme](https://github.com/handlebars-lang/handlebars.js#differences-between-handlebarsjs-and-mustache).
+
+## Why is it slower when compiling?
+
+The Handlebars compiler must parse the template and construct a JavaScript program which can then be run. Under some environments such as older mobile devices this can have a performance impact which can be avoided by precompiling. Generally it's recommended that precompilation and the runtime library be used on all clients.
+
+## Why doesn't this work with Content Security Policy restrictions?
+
+When not using the precompiler, Handlebars generates a dynamic function for each template which can cause issues with pages that have enabled Content Policy. It's recommended that templates are precompiled or the `unsafe-eval` policy is enabled for sites that must generate dynamic templates at runtime.
+
+## How can I include script tags in my template?
+
+If loading the template via an inlined `<script type="text/x-handlebars">` tag then you may need to break up the script tag with an empty comment to avoid browser parser errors:
+
+```html
+<script type="text/x-handlebars">
+  foo
+  <scr{{!}}ipt src="bar"></scr{{!}}ipt>
+</script>
+```
+
+It's generally recommended that templates are served through external, precompiled, files, which do not suffer from this issue.
+
+## Why are my precompiled scripts throwing exceptions?
+
+When using the precompiler, it's important that a supporting version of the Handlebars runtime be loaded on the target page. In version 1.x there were rudimentary checks to compare the version but these did not always work. This is fixed under 2.x but the version checking does not work between these two versions. If you see unexpected errors such as `undefined is not a function` or similar, please verify that the same version is being used for both the precompiler and the client. This can be checked via:
+
+```sh
+handlebars --version
+```
+
+If using the integrated precompiler and
+
+```javascript
+console.log(Handlebars.VERSION);
+```
+
+On the client side.
+
+We include the built client libraries in the npm package for those who want to be certain that they are using the same client libraries as the compiler.
+
+Should these match, please file an issue with us, per our [issue filing guidelines](https://github.com/handlebars-lang/handlebars.js/blob/master/CONTRIBUTING.md#reporting-issues).
+
+## How do I load the runtime library when using AMD?
+
+The `handlebars.runtime.js` file includes a UMD build, which exposes the library as both the module root and the `default` field for compatibility.

Gruntfile.js

@@ -1,200 +0,0 @@
-var childProcess = require('child_process');
-
-module.exports = function(grunt) {
-
-  grunt.initConfig({
-    pkg: grunt.file.readJSON('package.json'),
-
-    jshint: {
-      options: {
-        jshintrc: '.jshintrc'
-      },
-      files: [
-        'dist/cjs/**/!(*.min|parser).js'
-      ]
-    },
-
-    clean: ['tmp', 'dist', 'lib/handlebars/compiler/parser.js'],
-
-    copy: {
-      dist: {
-        options: {
-          processContent: function(content, path) {
-            return grunt.template.process('/*!\n\n <%= pkg.name %> v<%= pkg.version %>\n\n<%= grunt.file.read("LICENSE") %>\n@license\n*/\n')
-                + content;
-          }
-        },
-        files: [
-          {expand: true, cwd: 'dist/', src: ['*.js'], dest: 'dist/'}
-        ]
-      },
-      cdnjs: {
-        files: [
-          {expand: true, cwd: 'dist/', src: ['*.js'], dest: 'dist/cdnjs'}
-        ]
-      },
-      components: {
-        files: [
-          {expand: true, cwd: 'components/', src: ['**'], dest: 'dist/components'},
-          {expand: true, cwd: 'dist/', src: ['*.js'], dest: 'dist/components'}
-        ]
-      }
-    },
-
-    packager: {
-      global: {
-        type: 'global',
-        export: 'Handlebars',
-        files: [{
-          cwd: 'lib/',
-          expand: true,
-          src: ['handlebars*.js'],
-          dest: 'dist/'
-        }]
-      },
-
-      amd: {
-        type: 'amd',
-        anonymous: true,
-        files: [{
-          expand: true,
-          cwd: 'lib/',
-          src: '**/!(index).js',
-          dest: 'dist/amd/'
-        }]
-      },
-
-      cjs: {
-        type: 'cjs',
-        files: [{
-          expand: true,
-          cwd: 'lib/',
-          src: '**/!(index).js',
-          dest: 'dist/cjs/'
-        }]
-      }
-    },
-    requirejs: {
-      options: {
-        optimize: "none",
-        baseUrl: "dist/amd/"
-      },
-      dist: {
-        options: {
-          name: "handlebars",
-          out: "dist/handlebars.amd.js"
-        }
-      },
-      runtime: {
-        options: {
-          name: "handlebars.runtime",
-          out: "dist/handlebars.runtime.amd.js"
-        }
-      }
-    },
-
-    uglify: {
-      options: {
-        mangle: true,
-        compress: true,
-        preserveComments: 'some'
-      },
-      dist: {
-        files: [{
-          cwd: 'dist/',
-          expand: true,
-          src: ['handlebars*.js', '!*.min.js'],
-          dest: 'dist/',
-          rename: function(dest, src) {
-            return dest + src.replace(/\.js$/, '.min.js');
-          }
-        }]
-      }
-    },
-
-    concat: {
-      tests: {
-        src: ['spec/!(require).js'],
-        dest: 'tmp/tests.js'
-      }
-    },
-
-    connect: {
-      server: {
-        options: {
-          base: '.',
-          hostname: '*',
-          port: 9999
-        }
-      }
-    },
-    'saucelabs-mocha': {
-      all: {
-        options: {
-          build: process.env.TRAVIS_JOB_ID,
-          urls: ['http://localhost:9999/spec/?headless=true', 'http://localhost:9999/spec/amd.html?headless=true'],
-          detailedError: true,
-          concurrency: 2,
-          browsers: [
-            {browserName: 'chrome'},
-            {browserName: 'firefox'},
-            {browserName: 'firefox', version: '3.6'},
-            {browserName: 'safari', version: 7, platform: 'OS X 10.9'},
-            {browserName: 'safari', version: 6, platform: 'OS X 10.8'},
-            {browserName: 'internet explorer', version: 11, platform: 'Windows 8.1'},
-            {browserName: 'internet explorer', version: 10, platform: 'Windows 8'},
-            {browserName: 'internet explorer', version: 9, platform: 'Windows 7'},
-            {browserName: 'internet explorer', version: 6, platform: 'XP'}
-          ]
-        }
-      }
-    },
-
-    watch: {
-      scripts: {
-        options: {
-          atBegin: true
-        },
-
-        files: ['src/*', 'lib/**/*.js', 'spec/**/*.js'],
-        tasks: ['build', 'amd', 'tests', 'test']
-      }
-    }
-  });
-
-  // Build a new version of the library
-  this.registerTask('build', "Builds a distributable version of the current project", [
-                    'parser',
-                    'node',
-                    'globals',
-                    'jshint']);
-
-  this.registerTask('amd', ['packager:amd', 'requirejs']);
-  this.registerTask('node', ['packager:cjs']);
-  this.registerTask('globals', ['packager:global']);
-  this.registerTask('tests', ['concat:tests']);
-
-  this.registerTask('release', 'Build final packages', ['amd', 'jshint', 'uglify', 'copy:dist', 'copy:components', 'copy:cdnjs']);
-
-  // Load tasks from npm
-  grunt.loadNpmTasks('grunt-contrib-clean');
-  grunt.loadNpmTasks('grunt-contrib-concat');
-  grunt.loadNpmTasks('grunt-contrib-connect');
-  grunt.loadNpmTasks('grunt-contrib-copy');
-  grunt.loadNpmTasks('grunt-contrib-requirejs');
-  grunt.loadNpmTasks('grunt-contrib-jshint');
-  grunt.loadNpmTasks('grunt-contrib-uglify');
-  grunt.loadNpmTasks('grunt-contrib-watch');
-  grunt.loadNpmTasks('grunt-saucelabs');
-  grunt.loadNpmTasks('es6-module-packager');
-
-  grunt.task.loadTasks('tasks');
-
-  grunt.registerTask('bench', ['metrics']);
-  grunt.registerTask('sauce', process.env.SAUCE_USERNAME ? ['tests', 'connect', 'saucelabs-mocha'] : []);
-
-  grunt.registerTask('travis', process.env.PUBLISH ? ['default', 'sauce', 'metrics', 'publish:latest'] : ['default']);
-
-  grunt.registerTask('dev', ['clean', 'connect', 'watch']);
-  grunt.registerTask('default', ['clean', 'build', 'test', 'release']);
-};

LICENSE

@@ -1,4 +1,4 @@
-Copyright (C) 2011-2014 by Yehuda Katz
+Copyright (C) 2011-2019 by Yehuda Katz
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal

README.markdown

@@ -1,469 +0,0 @@
-[![Travis Build Status](https://travis-ci.org/wycats/handlebars.js.png?branch=master)](https://travis-ci.org/wycats/handlebars.js)
-[![Selenium Test Status](https://saucelabs.com/buildstatus/handlebars)](https://saucelabs.com/u/handlebars)
-
-Handlebars.js
-=============
-
-Handlebars.js is an extension to the [Mustache templating
-language](http://mustache.github.com/) created by Chris Wanstrath.
-Handlebars.js and Mustache are both logicless templating languages that
-keep the view and the code separated like we all know they should be.
-
-Checkout the official Handlebars docs site at
-[http://www.handlebarsjs.com](http://www.handlebarsjs.com).
-
-Installing
-----------
-Installing Handlebars is easy. Simply download the package [from the official site](http://handlebarsjs.com/) or the [bower repository][bower-repo] and add it to your web pages (you should usually use the most recent version).
-
-Alternatively, if you prefer having the latest version of handlebars from
-the 'master' branch, passing builds of the 'master' branch are automatically
-published to S3. You may download the latest passing master build by grabbing
-a `handlebars-latest.js` file from the [builds page][builds-page]. When the
-build is published, it is also available as a `handlebars-gitSHA.js` file on
-the builds page if you need a version to refer to others.
-`handlebars-runtime.js` builds are also available.
-
-**Note**: The S3 builds page is provided as a convenience for the community,
-but you should not use it for hosting Handlebars in production.
-
-Usage
------
-In general, the syntax of Handlebars.js templates is a superset
-of Mustache templates. For basic syntax, check out the [Mustache
-manpage](http://mustache.github.com/mustache.5.html).
-
-Once you have a template, use the `Handlebars.compile` method to compile
-the template into a function. The generated function takes a context
-argument, which will be used to render the template.
-
-```js
-var source = "<p>Hello, my name is {{name}}. I am from {{hometown}}. I have " +
-             "{{kids.length}} kids:</p>" +
-             "<ul>{{#kids}}<li>{{name}} is {{age}}</li>{{/kids}}</ul>";
-var template = Handlebars.compile(source);
-
-var data = { "name": "Alan", "hometown": "Somewhere, TX",
-             "kids": [{"name": "Jimmy", "age": "12"}, {"name": "Sally", "age": "4"}]};
-var result = template(data);
-
-// Would render:
-// <p>Hello, my name is Alan. I am from Somewhere, TX. I have 2 kids:</p>
-// <ul>
-//   <li>Jimmy is 12</li>
-//   <li>Sally is 4</li>
-// </ul>
-```
-
-
-Registering Helpers
--------------------
-
-You can register helpers that Handlebars will use when evaluating your
-template. Here's an example, which assumes that your objects have a URL
-embedded in them, as well as the text for a link:
-
-```js
-Handlebars.registerHelper('link_to', function() {
-  return new Handlebars.SafeString("<a href='" + Handlebars.Utils.escapeExpression(this.url) + "'>" + Handlebars.Utils.escapeExpression(this.body) + "</a>");
-});
-
-var context = { posts: [{url: "/hello-world", body: "Hello World!"}] };
-var source = "<ul>{{#posts}}<li>{{link_to}}</li>{{/posts}}</ul>"
-
-var template = Handlebars.compile(source);
-template(context);
-
-// Would render:
-//
-// <ul>
-//   <li><a href='/hello-world'>Hello World!</a></li>
-// </ul>
-```
-
-Helpers take precedence over fields defined on the context. To access a field
-that is masked by a helper, a path reference may be used. In the example above
-a field named `link_to` on the `context` object would be referenced using:
-
-```
-{{./link_to}}
-```
-
-Escaping
---------
-
-By default, the `{{expression}}` syntax will escape its contents. This
-helps to protect you against accidental XSS problems caused by malicious
-data passed from the server as JSON.
-
-To explicitly *not* escape the contents, use the triple-mustache
-(`{{{}}}`). You have seen this used in the above example.
-
-
-Differences Between Handlebars.js and Mustache
-----------------------------------------------
-Handlebars.js adds a couple of additional features to make writing
-templates easier and also changes a tiny detail of how partials work.
-
-### Paths
-
-Handlebars.js supports an extended expression syntax that we call paths.
-Paths are made up of typical expressions and . characters. Expressions
-allow you to not only display data from the current context, but to
-display data from contexts that are descendants and ancestors of the
-current context.
-
-To display data from descendant contexts, use the `.` character. So, for
-example, if your data were structured like:
-
-```js
-var data = {"person": { "name": "Alan" }, "company": {"name": "Rad, Inc." } };
-```
-
-You could display the person's name from the top-level context with the
-following expression:
-
-```
-{{person.name}}
-```
-
-You can backtrack using `../`. For example, if you've already traversed
-into the person object you could still display the company's name with
-an expression like `{{../company.name}}`, so:
-
-```
-{{#with person}}{{name}} - {{../company.name}}{{/person}}
-```
-
-would render:
-
-```
-Alan - Rad, Inc.
-```
-
-### Strings
-
-When calling a helper, you can pass paths or Strings as parameters. For
-instance:
-
-```js
-Handlebars.registerHelper('link_to', function(title, options) {
-  return "<a href='/posts" + this.url + "'>" + title + "!</a>"
-});
-
-var context = { posts: [{url: "/hello-world", body: "Hello World!"}] };
-var source = '<ul>{{#posts}}<li>{{{link_to "Post"}}}</li>{{/posts}}</ul>'
-
-var template = Handlebars.compile(source);
-template(context);
-
-// Would render:
-//
-// <ul>
-//   <li><a href='/posts/hello-world'>Post!</a></li>
-// </ul>
-```
-
-When you pass a String as a parameter to a helper, the literal String
-gets passed to the helper function.
-
-
-### Block Helpers
-
-Handlebars.js also adds the ability to define block helpers. Block
-helpers are functions that can be called from anywhere in the template.
-Here's an example:
-
-```js
-var source = "<ul>{{#people}}<li>{{#link}}{{name}}{{/link}}</li>{{/people}}</ul>";
-Handlebars.registerHelper('link', function(options) {
-  return '<a href="/people/' + this.id + '">' + options.fn(this) + '</a>';
-});
-var template = Handlebars.compile(source);
-
-var data = { "people": [
-    { "name": "Alan", "id": 1 },
-    { "name": "Yehuda", "id": 2 }
-  ]};
-template(data);
-
-// Should render:
-// <ul>
-//   <li><a href="/people/1">Alan</a></li>
-//   <li><a href="/people/2">Yehuda</a></li>
-// </ul>
-```
-
-Whenever the block helper is called it is given one or more parameters,
-any arguments that are passed in the helper in the call and an `options`
-object containing the `fn` function which executes the block's child.
-The block's current context may be accessed through `this`.
-
-Block helpers have the same syntax as mustache sections but should not be
-confused with one another. Sections are akin to an implicit `each` or
-`with` statement depending on the input data and helpers are explicit
-pieces of code that are free to implement whatever behavior they like.
-The [mustache spec](http://mustache.github.io/mustache.5.html)
-defines the exact behavior of sections. In the case of name conflicts,
-helpers are given priority.
-
-### Partials
-
-You can register additional templates as partials, which will be used by
-Handlebars when it encounters a partial (`{{> partialName}}`). Partials
-can either be String templates or compiled template functions. Here's an
-example:
-
-```js
-var source = "<ul>{{#people}}<li>{{> link}}</li>{{/people}}</ul>";
-
-Handlebars.registerPartial('link', '<a href="/people/{{id}}">{{name}}</a>')
-var template = Handlebars.compile(source);
-
-var data = { "people": [
-    { "name": "Alan", "id": 1 },
-    { "name": "Yehuda", "id": 2 }
-  ]};
-
-template(data);
-
-// Should render:
-// <ul>
-//   <li><a href="/people/1">Alan</a></li>
-//   <li><a href="/people/2">Yehuda</a></li>
-// </ul>
-```
-
-### Comments
-
-You can add comments to your templates with the following syntax:
-
-```js
-{{! This is a comment }}
-```
-
-You can also use real html comments if you want them to end up in the output.
-
-```html
-<div>
-    {{! This comment will not end up in the output }}
-    <!-- This comment will show up in the output -->
-</div>
-```
-
-
-Precompiling Templates
-----------------------
-
-Handlebars allows templates to be precompiled and included as javascript
-code rather than the handlebars template allowing for faster startup time.
-
-### Installation
-The precompiler script may be installed via npm using the `npm install -g handlebars`
-command.
-
-### Usage
-
-<pre>
-Precompile handlebar templates.
-Usage: handlebars template...
-
-Options:
-  -a, --amd            Create an AMD format function (allows loading with RequireJS)          [boolean]
-  -f, --output         Output File                                                            [string]
-  -k, --known          Known helpers                                                          [string]
-  -o, --knownOnly      Known helpers only                                                     [boolean]
-  -m, --min            Minimize output                                                        [boolean]
-  -s, --simple         Output template function only.                                         [boolean]
-  -r, --root           Template root. Base value that will be stripped from template names.   [string]
-  -c, --commonjs       Exports CommonJS style, path to Handlebars module                      [string]
-  -h, --handlebarPath  Path to handlebar.js (only valid for amd-style)                        [string]
-  -n, --namespace      Template namespace                                                     [string]
-  -p, --partial        Compiling a partial template                                           [boolean]
-  -d, --data           Include data when compiling                                            [boolean]
-  -e, --extension      Template extension.                                                    [string]
-  -b, --bom            Removes the BOM (Byte Order Mark) from the beginning of the templates. [boolean]
-</pre>
-
-If using the precompiler's normal mode, the resulting templates will be
-stored to the `Handlebars.templates` object using the relative template
-name sans the extension. These templates may be executed in the same
-manner as templates.
-
-If using the simple mode the precompiler will generate a single
-javascript method. To execute this method it must be passed to the using
-the `Handlebars.template` method and the resulting object may be as
-normal.
-
-### Optimizations
-
-- Rather than using the full _handlebars.js_ library, implementations that
-  do not need to compile templates at runtime may include _handlebars.runtime.js_
-  whose min+gzip size is approximately 1k.
-- If a helper is known to exist in the target environment they may be defined
-  using the `--known name` argument may be used to optimize accesses to these
-  helpers for size and speed.
-- When all helpers are known in advance the `--knownOnly` argument may be used
-  to optimize all block helper references.
-- Implementations that do not use `@data` variables can improve performance of
-  iteration centric templates by specifying `{data: false}` in the compiler options.
-
-Supported Environments
-----------------------
-
-Handlebars has been designed to work in any ECMAScript 3 environment. This includes
-
-- Node.js
-- Chrome
-- Firefox
-- Safari 5+
-- Opera 11+
-- IE 6+
-
-Older versions and other runtimes are likely to work but have not been formally
-tested. The compiler requires `JSON.stringify` to be implemented natively or via a polyfill. If using the precompiler this is not necessary.
-
-[![Selenium Test Status](https://saucelabs.com/browser-matrix/handlebars.svg)](https://saucelabs.com/u/handlebars)
-
-Performance
------------
-
-In a rough performance test, precompiled Handlebars.js templates (in
-the original version of Handlebars.js) rendered in about half the
-time of Mustache templates. It would be a shame if it were any other
-way, since they were precompiled, but the difference in architecture
-does have some big performance advantages. Justin Marney, a.k.a.
-[gotascii](http://github.com/gotascii), confirmed that with an
-[independent test](http://sorescode.com/2010/09/12/benchmarks.html). The
-rewritten Handlebars (current version) is faster than the old version,
-and we will have some benchmarks in the near future.
-
-
-Building
---------
-
-To build handlebars, just run `grunt build`, and the build will output to the `dist` directory.
-
-
-Upgrading
----------
-
-See [release-notes.md](https://github.com/wycats/handlebars.js/blob/master/release-notes.md) for upgrade notes.
-
-Known Issues
-------------
-* Runtime/precompiler mismatches: Often result in errors like "can not find method match of object" or similar. Please verify the version of the runtime and the version used to precompile templates if odd issues occur after upgrading one component or another.
-* Handlebars.js can be cryptic when there's an error while rendering.
-* Using a variable, helper, or partial named `class` causes errors in IE browsers. (Instead, use `className`)
-
-Reporting Issues
-----------------
-
-Should you run into other issues with the project, please file an [issue][issue]. When filing issues a repo case running against the latest version of the code is appreciated. A [jsfiddle template][jsfiddle] is available for this purpose. As new versions are released the bitly link will be updated to point to a fiddle template with the latest version.
-
-We also accept [pull requests][pull-request]!
-
-Handlebars in the Wild
-----------------------
-
-* [Assemble](http://assemble.io), by [@jonschlinkert](https://github.com/jonschlinkert)
-  and [@doowb](https://github.com/doowb), is a static site generator that uses Handlebars.js
-  as its template engine.
-* [CoSchedule](http://coschedule.com) An editorial calendar for WordPress that uses Handlebars.js
-* [Ember.js](http://www.emberjs.com) makes Handlebars.js the primary way to
-  structure your views, also with automatic data binding support.
-* [Ghost](https://ghost.org/) Just a blogging platform.
-* [handlebars_assets](http://github.com/leshill/handlebars_assets): A Rails Asset Pipeline gem
-  from Les Hill (@leshill).
-* [handlebars-helpers](https://github.com/assemble/handlebars-helpers) is an extensive library
-  with 100+ handlebars helpers.
-* [hbs](http://github.com/donpark/hbs): An Express.js view engine adapter for Handlebars.js,
-  from Don Park.
-* [koa-hbs](https://github.com/jwilm/koa-hbs): [koa](https://github.com/koajs/koa) generator based
-  renderer for Handlebars.js.
-* [jblotus](http://github.com/jblotus) created [http://tryhandlebarsjs.com](http://tryhandlebarsjs.com)
-  for anyone who would like to try out Handlebars.js in their browser.
-* [jQuery plugin](http://71104.github.io/jquery-handlebars/): allows you to use
-  Handlebars.js with [jQuery](http://jquery.com/).
-* [Lumbar](http://walmartlabs.github.io/lumbar) provides easy module-based template management for
-  handlebars projects.
-* [sammy.js](http://github.com/quirkey/sammy) by Aaron Quint, a.k.a. quirkey,
-  supports Handlebars.js as one of its template plugins.
-* [SproutCore](http://www.sproutcore.com) uses Handlebars.js as its main
-  templating engine, extending it with automatic data binding support.
-* [YUI](http://yuilibrary.com/yui/docs/handlebars/) implements a port of handlebars
-* [Swag](https://github.com/elving/swag) by [@elving](https://github.com/elving) is a growing collection of helpers for handlebars.js. Give your handlebars.js templates some swag son!
-* [DOMBars](https://github.com/blakeembrey/dombars) is a DOM-based templating engine built on the Handlebars parser and runtime
-
-External Resources
-------------------
-
-* [Gist about Synchronous and asynchronous loading of external handlebars templates](https://gist.github.com/2287070)
-
-Have a project using Handlebars? Send us a [pull request][pull-request]!
-
-Helping Out
------------
-
-To build Handlebars.js you'll need a few things installed.
-
-* Node.js
-* [Grunt](http://gruntjs.com/getting-started)
-
-Project dependencies may be installed via `npm install`.
-
-To build Handlebars.js from scratch, you'll want to run `grunt`
-in the root of the project. That will build Handlebars and output the
-results to the dist/ folder. To re-run tests, run `grunt test` or `npm test`.
-You can also run our set of benchmarks with `grunt bench`.
-
-The `grunt dev` implements watching for tests and allows for in browser testing at `http://localhost:9999/spec/`.
-
-If you notice any problems, please report them to the GitHub issue tracker at
-[http://github.com/wycats/handlebars.js/issues](http://github.com/wycats/handlebars.js/issues).
-Feel free to contact commondream or wycats through GitHub with any other
-questions or feature requests. To submit changes fork the project and
-send a pull request.
-
-### Ember testing
-
-The current ember distribution should be tested as part of the handlebars release process. This requires building the `handlebars-source` gem locally and then executing the ember test script.
-
-```sh
-grunt build release
-export HANDLEBARS_PATH=`pwd`
-
-cd $emberRepoDir
-bundle exec rake clean
-bundle exec rake test
-```
-
-### Releasing
-
-Handlebars utilizes the [release yeoman generator][generator-release] to perform most release tasks.
-
-A full release may be completed with the following:
-
-```
-yo release
-npm publish
-yo release:publish cdnjs handlebars.js dist/cdnjs/
-yo release:publish components handlebars.js dist/components/
-
-cd dist/components/
-gem build handlebars-source.gemspec
-gem push handlebars-source-*.gem
-```
-
-After this point the handlebars site needs to be updated to point to the new version numbers. The jsfiddle bitly link should be updated to point to the most recent distribution.
-
-License
--------
-Handlebars.js is released under the MIT license.
-
-[bower-repo]: https://github.com/components/handlebars.js
-[builds-page]: http://builds.handlebarsjs.com.s3.amazonaws.com/bucket-listing.html?sort=lastmod&sortdir=desc
-[generator-release]: https://github.com/walmartlabs/generator-release
-[pull-request]: https://github.com/wycats/handlebars.js/pull/new/master
-[issue]: https://github.com/wycats/handlebars.js/issues/new
-[jsfiddle]: http://l.kde.cc/hbs-bug

README.md

@@ -0,0 +1,198 @@
+[![CI Build Status](https://github.com/handlebars-lang/handlebars.js/actions/workflows/ci.yml/badge.svg)](https://github.com/handlebars-lang/handlebars.js/actions/workflows/ci.yml)
+[![jsDelivr Hits](https://data.jsdelivr.com/v1/package/npm/handlebars/badge?style=rounded)](https://www.jsdelivr.com/package/npm/handlebars)
+[![npm downloads](https://badgen.net/npm/dm/handlebars)](https://www.npmjs.com/package/handlebars)
+[![npm version](https://badgen.net/npm/v/handlebars)](https://www.npmjs.com/package/handlebars)
+[![Bundle size](https://badgen.net/bundlephobia/minzip/handlebars?label=minified%20%2B%20gzipped)](https://bundlephobia.com/package/handlebars)
+[![Install size](https://packagephobia.com/badge?p=handlebars)](https://packagephobia.com/result?p=handlebars)
+
+# Handlebars.js
+
+Handlebars provides the power necessary to let you build **semantic templates** effectively with no frustration.
+Handlebars is largely compatible with Mustache templates. In most cases it is possible to swap out Mustache with Handlebars and continue using your current templates.
+
+Checkout the official Handlebars docs site at
+[handlebarsjs.com](https://handlebarsjs.com) and try our [live demo](https://handlebarsjs.com/playground.html).
+
+## Installing
+
+See our [installation documentation](https://handlebarsjs.com/guide/installation/).
+
+## Usage
+
+In general, the syntax of Handlebars.js templates is a superset
+of Mustache templates. For basic syntax, check out the [Mustache
+manpage](https://mustache.github.io/mustache.5.html).
+
+Once you have a template, use the `Handlebars.compile` method to compile
+the template into a function. The generated function takes a context
+argument, which will be used to render the template.
+
+```js
+var source =
+  '<p>Hello, my name is {{name}}. I am from {{hometown}}. I have ' +
+  '{{kids.length}} kids:</p>' +
+  '<ul>{{#kids}}<li>{{name}} is {{age}}</li>{{/kids}}</ul>';
+var template = Handlebars.compile(source);
+
+var data = {
+  name: 'Alan',
+  hometown: 'Somewhere, TX',
+  kids: [
+    { name: 'Jimmy', age: '12' },
+    { name: 'Sally', age: '4' },
+  ],
+};
+var result = template(data);
+
+// Would render:
+// <p>Hello, my name is Alan. I am from Somewhere, TX. I have 2 kids:</p>
+// <ul>
+//   <li>Jimmy is 12</li>
+//   <li>Sally is 4</li>
+// </ul>
+```
+
+Full documentation and more examples are at [handlebarsjs.com](https://handlebarsjs.com/).
+
+## Precompiling Templates
+
+Handlebars allows templates to be precompiled and included as javascript code rather than the handlebars template allowing for faster startup time. Full details are located [here](https://handlebarsjs.com/guide/installation/precompilation.html).
+
+## Differences Between Handlebars.js and Mustache
+
+Handlebars.js adds a couple of additional features to make writing
+templates easier and also changes a tiny detail of how partials work.
+
+- [Nested Paths](https://handlebarsjs.com/guide/expressions.html#path-expressions)
+- [Helpers](https://handlebarsjs.com/guide/expressions.html#helpers)
+- [Block Expressions](https://handlebarsjs.com/guide/block-helpers.html#basic-blocks)
+- [Literal Values](https://handlebarsjs.com/guide/expressions.html#literal-segments)
+- [Delimited Comments](https://handlebarsjs.com/guide/#template-comments)
+
+Block expressions have the same syntax as mustache sections but should not be confused with one another. Sections are akin to an implicit `each` or `with` statement depending on the input data and helpers are explicit pieces of code that are free to implement whatever behavior they like. The [mustache spec](https://mustache.github.io/mustache.5.html) defines the exact behavior of sections. In the case of name conflicts, helpers are given priority.
+
+### Compatibility
+
+There are a few Mustache behaviors that Handlebars does not implement.
+
+- Handlebars deviates from Mustache slightly in that it does not perform recursive lookup by default. The compile time `compat` flag must be set to enable this functionality. Users should note that there is a performance cost for enabling this flag. The exact cost varies by template, but it's recommended that performance sensitive operations should avoid this mode and instead opt for explicit path references.
+- The optional Mustache-style lambdas are not supported. Instead Handlebars provides its own lambda resolution that follows the behaviors of helpers.
+- Handlebars does not allow space between the opening `{{` and a command character such as `#`, `/` or `>`. The command character must immediately follow the braces, so for example `{{> partial }}` is allowed but `{{ > partial }}` is not.
+- Alternative delimiters are not supported.
+
+## Supported Environments
+
+Handlebars has been designed to work in any ECMAScript 2020 environment. This includes
+
+- Node.js
+- Chrome
+- Firefox
+- Safari
+- Edge
+
+If you need to support older environments, use Handlebars version 4.
+
+## Performance
+
+In a rough performance test, precompiled Handlebars.js templates (in
+the original version of Handlebars.js) rendered in about half the
+time of Mustache templates. It would be a shame if it were any other
+way, since they were precompiled, but the difference in architecture
+does have some big performance advantages. Justin Marney, a.k.a.
+[gotascii](http://github.com/gotascii), confirmed that with an
+[independent test](http://sorescode.com/2010/09/12/benchmarks.html). The
+rewritten Handlebars (current version) is faster than the old version,
+with many performance tests being 5 to 7 times faster than the Mustache equivalent.
+
+### Benchmarks
+
+The project includes a comprehensive benchmark suite (powered by [tinybench](https://github.com/tinylibs/tinybench)) that measures compilation, execution, precompilation, and end-to-end performance across templates of varying size and complexity.
+
+```bash
+# Run benchmarks (auto-labels with current git branch)
+npm run bench
+
+# Run with a custom label
+npm run bench -- --label my-optimization
+
+# Filter templates by name (regex, case-insensitive)
+npm run bench -- --grep "complex|recursive"
+
+# Run only specific sections (regex, case-insensitive)
+npm run bench -- --section precompil
+npm run bench -- --section "compilation|precompil"
+
+# Compare results
+npm run bench:compare
+
+# Or specify files explicitly
+npm run bench:compare -- bench/results/bench-*-main.md bench/results/bench-*-feat.md
+```
+
+Results are saved as timestamped Markdown files in `bench/results/`. Each report includes ops/sec, avg latency, p50/p75/p99 percentiles, and sample counts.
+
+Typical workflow for comparing branches:
+
+```bash
+git checkout main && npm run bench
+git checkout my-feature && npm run bench
+npm run bench:compare
+```
+
+When run without arguments, `bench:compare` auto-selects two result files: if a file labelled "main" exists it is always used as the baseline, otherwise the older file is the baseline. The comparison uses p75 latency for the diff to filter outliers, and marks changes with `!` (>2%) and `!!` (>5%).
+
+## Upgrading
+
+See [release-notes.md](https://github.com/handlebars-lang/handlebars.js/blob/master/release-notes.md) for upgrade notes.
+
+If you are using Handlebars in production, please regularly look for issues labeled
+[possibly breaking](https://github.com/handlebars-lang/handlebars.js/issues?q=is%3Aopen+is%3Aissue+label%3A%22possibly+breaking%22).
+If this label is applied to an issue, it means that the requested change is probably not a breaking change,
+but since Handlebars is widely in use by a lot of people, there's always a chance that it breaks somebody's build.
+
+## Known Issues
+
+See [FAQ.md](https://github.com/handlebars-lang/handlebars.js/blob/master/FAQ.md) for known issues and common pitfalls.
+
+## Handlebars in the Wild
+
+- [apiDoc](https://github.com/apidoc/apidoc) apiDoc uses handlebars as parsing engine for api documentation view generation.
+- [Assemble](https://assemble.io), by [@jonschlinkert](https://github.com/jonschlinkert) and [@doowb](https://github.com/doowb), is a static site generator that uses Handlebars.js as its template engine.
+- [CoSchedule](https://coschedule.com) An editorial calendar for WordPress that uses Handlebars.js.
+- [Ember.js](https://www.emberjs.com) makes Handlebars.js the primary way to structure your views, also with automatic data binding support.
+- [express-handlebars](https://github.com/express-handlebars/express-handlebars) A Handlebars view engine for Express which doesn't suck.
+- [express-hbs](https://github.com/TryGhost/express-hbs) Express Handlebars template engine with inheritance, partials, i18n and async helpers.
+- [Ghost](https://ghost.org/) Just a blogging platform.
+- [handlebars-action](https://github.com/marketplace/actions/handlebars-action) A GitHub action to transform files in your repository with Handlebars templating.
+- [handlebars_assets](https://github.com/leshill/handlebars_assets) A Rails Asset Pipeline gem from Les Hill (@leshill).
+- [handlebars-helpers](https://github.com/assemble/handlebars-helpers) is an extensive library with 100+ handlebars helpers.
+- [handlebars-layouts](https://github.com/shannonmoeller/handlebars-layouts) is a set of helpers which implement extensible and embeddable layout blocks as seen in other popular templating languages.
+- [handlebars-loader](https://github.com/pcardune/handlebars-loader) A handlebars template loader for webpack.
+- [handlebars-wax](https://github.com/shannonmoeller/handlebars-wax) The missing Handlebars API. Effortless registration of data, partials, helpers, and decorators using file-system globs, modules, and plain-old JavaScript objects.
+- [hbs](https://github.com/pillarjs/hbs) An Express.js view engine adapter for Handlebars.js, from Don Park.
+- [html-bundler-webpack-plugin](https://github.com/webdiscus/html-bundler-webpack-plugin) The webpack plugin to compile templates, [supports Handlebars](https://github.com/webdiscus/html-bundler-webpack-plugin#using-template-handlebars).
+- [incremental-bars](https://github.com/atomictag/incremental-bars) adds support for [incremental-dom](https://github.com/google/incremental-dom) as template target to Handlebars.
+- [jQuery plugin](https://71104.github.io/jquery-handlebars/) allows you to use Handlebars.js with [jQuery](http://jquery.com/).
+- [just-handlebars-helpers](https://github.com/leapfrogtechnology/just-handlebars-helpers) A fully tested lightweight package with common Handlebars helpers.
+- [koa-hbs](https://github.com/jwilm/koa-hbs) [koa](https://github.com/koajs/koa) generator based renderer for Handlebars.js.
+- [Marionette.Handlebars](https://github.com/hashchange/marionette.handlebars) adds support for Handlebars and Mustache templates to Marionette.
+- [openVALIDATION](https://github.com/openvalidation/openvalidation) a natural language compiler for validation rules. Generates program code in Java, JavaScript, C#, Python and Rust with handlebars.
+- [Plop](https://plopjs.com/) is a micro-generator framework that makes it easy to create files with a level of uniformity.
+- [promised-handlebars](https://github.com/nknapp/promised-handlebars) is a wrapper for Handlebars that allows helpers to return Promises.
+- [sammy.js](https://github.com/quirkey/sammy) by Aaron Quint, a.k.a. quirkey, supports Handlebars.js as one of its template plugins.
+- [Swag](https://github.com/elving/swag) by [@elving](https://github.com/elving) is a growing collection of helpers for handlebars.js. Give your handlebars.js templates some swag son!
+- [SproutCore](https://www.sproutcore.com) uses Handlebars.js as its main templating engine, extending it with automatic data binding support.
+- [vite-plugin-handlebars](https://github.com/alexlafroscia/vite-plugin-handlebars) A package for Vite 2. Allows for running your HTML files through the Handlebars compiler.
+- [YUI](https://yuilibrary.com/yui/docs/handlebars/) implements a port of handlebars.
+
+## External Resources
+
+- [Gist about Synchronous and asynchronous loading of external handlebars templates](https://gist.github.com/2287070)
+
+Have a project using Handlebars? Send us a [pull request][pull-request]!
+
+## License
+
+Handlebars.js is released under the MIT license.
+
+[pull-request]: https://github.com/handlebars-lang/handlebars.js/pull/new/master

SECURITY.md

@@ -0,0 +1,15 @@
+# Security Policy
+
+We recommend always using the latest versions of Handlebars and its official companion libraries to ensure your application remains as secure as possible.
+
+## Supported Versions
+
+| Version | Supported          |
+| ------- | ------------------ |
+| 5.0.x   | :white_check_mark: |
+| 4.7.x   | :white_check_mark: |
+| < 4.7   | :x:                |
+
+## Reporting a Vulnerability
+
+To report a vulnerability, please visit https://github.com/handlebars-lang/handlebars.js/security.

bench/dist-size.js

@@ -1,39 +0,0 @@
-var _ = require('underscore'),
-    async = require('async'),
-    fs = require('fs'),
-    zlib = require('zlib');
-
-module.exports = function(grunt, callback) {
-  var distFiles = fs.readdirSync('dist'),
-      distSizes = {};
-
-  async.each(distFiles, function(file, callback) {
-      var content;
-      try {
-        content = fs.readFileSync('dist/' + file);
-      } catch (err) {
-        if (err.code === 'EISDIR') {
-          callback();
-          return;
-        } else {
-          throw err;
-        }
-      }
-
-      file = file.replace(/\.js/, '').replace(/\./g, '_');
-      distSizes[file] = content.length;
-
-      zlib.gzip(content, function(err, data) {
-        if (err) {
-          throw err;
-        }
-
-        distSizes[file + '_gz'] = data.length;
-        callback();
-      });
-    },
-    function() {
-      grunt.log.writeln('Distribution sizes: ' + JSON.stringify(distSizes, undefined, 2));
-      callback([distSizes]);
-    });
-};

bench/index.js

@@ -1,14 +0,0 @@
-var fs = require('fs');
-
-var metrics = fs.readdirSync(__dirname);
-metrics.forEach(function(metric) {
-  if (metric === 'index.js' || !/(.*)\.js$/.test(metric)) {
-    return;
-  }
-
-  var name = RegExp.$1;
-  metric = require('./' + name);
-  if (metric instanceof Function) {
-    module.exports[name] = metric;
-  }
-});

bench/precompile-size.js

@@ -1,19 +0,0 @@
-var _ = require('underscore'),
-    templates = require('./templates');
-
-module.exports = function(grunt, callback) {
-  // Deferring to here in case we have a build for parser, etc as part of this grunt exec
-  var Handlebars = require('../lib');
-
-  var templateSizes = {};
-  _.each(templates, function(info, template) {
-    var src = info.handlebars,
-        compiled = Handlebars.precompile(src, {}),
-        knownHelpers = Handlebars.precompile(src, {knownHelpersOnly: true, knownHelpers: info.helpers});
-
-    templateSizes[template] = compiled.length;
-    templateSizes['knownOnly_' + template] = knownHelpers.length;
-  });
-  grunt.log.writeln('Precompiled sizes: ' + JSON.stringify(templateSizes, undefined, 2));
-  callback([templateSizes]);
-};

bench/templates/arguments.js

@@ -1,12 +0,0 @@
-module.exports = {
-  helpers: {
-    foo: function(options) {
-      return '';
-    }
-  },
-  context: {
-    bar: true
-  },
-
-  handlebars: '{{foo person "person" 1 true foo=bar foo="person" foo=1 foo=true}}'
-};

bench/templates/array-each.js

@@ -1,7 +0,0 @@
-module.exports = {
-  context: { names: [{name: "Moe"}, {name: "Larry"}, {name: "Curly"}, {name: "Shemp"}] },
-  handlebars: "{{#each names}}{{name}}{{/each}}",
-  dust: "{#names}{name}{/names}",
-  mustache: "{{#names}}{{name}}{{/names}}",
-  eco: "<% for item in @names: %><%= item.name %><% end %>"
-};

bench/templates/array-mustache.js

@@ -1,4 +0,0 @@
-module.exports = {
-  context: { names: [{name: "Moe"}, {name: "Larry"}, {name: "Curly"}, {name: "Shemp"}] },
-  handlebars: "{{#names}}{{name}}{{/names}}"
-}

bench/templates/complex.dust

@@ -1,14 +0,0 @@
-<h1>{header}</h1>
-{?items}
-  <ul>
-    {#items}
-      {#current}
-        <li><strong>{name}</strong></li>
-      {:else}
-        <li><a href="{url}">{name}</a></li>
-      {/current}
-    {/items}
-  </ul>
-{:else}
-  <p>The list is empty.</p>
-{/items}

bench/templates/complex.eco

@@ -1,14 +0,0 @@
-<h1><%= @header() %></h1>
-<% if @items.length: %>
-  <ul>
-    <% for item in @items: %>
-      <% if item.current: %>
-        <li><strong><%= item.name %></strong></li>
-      <% else: %>
-        <li><a href="<%= item.url %>"><%= item.name %></a></li>
-      <% end %>
-    <% end %>
-  </ul>
-<% else: %>
-  <p>The list is empty.</p>
-<% end %>

bench/templates/complex.handlebars

@@ -1,14 +0,0 @@
-<h1>{{header}}</h1>
-{{#if items}}
-  <ul>
-    {{#each items}}
-      {{#if current}}
-        <li><strong>{{name}}</strong></li>
-      {{^}}
-        <li><a href="{{url}}">{{name}}</a></li>
-      {{/if}}
-    {{/each}}
-  </ul>
-{{^}}
-  <p>The list is empty.</p>
-{{/if}}

bench/templates/complex.js

@@ -1,20 +0,0 @@
-var fs = require('fs');
-
-module.exports = {
-  context: {
-    header: function() {
-      return "Colors";
-    },
-    hasItems: true,   // To make things fairer in mustache land due to no `{{if}}` construct on arrays
-    items: [
-      {name: "red", current: true, url: "#Red"},
-      {name: "green", current: false, url: "#Green"},
-      {name: "blue", current: false, url: "#Blue"}
-    ]
-  },
-
-  handlebars: fs.readFileSync(__dirname + '/complex.handlebars').toString(),
-  dust: fs.readFileSync(__dirname + '/complex.dust').toString(),
-  eco: fs.readFileSync(__dirname + '/complex.eco').toString(),
-  mustache: fs.readFileSync(__dirname + '/complex.mustache').toString()
-};

bench/templates/complex.mustache

@@ -1,13 +0,0 @@
-<h1>{{header}}</h1>
-{{#hasItems}}
-  <ul>
-    {{#items}}
-      {{#current}}
-        <li><strong>{{name}}</strong></li>
-      {{/current}}
-      {{^current}}
-        <li><a href="{{url}}">{{name}}</a></li>
-      {{/current}}
-    {{/items}}
-  </ul>
-{{/hasItems}}

bench/templates/data.js

@@ -1,4 +0,0 @@
-module.exports = {
-  context: { names: [{name: "Moe"}, {name: "Larry"}, {name: "Curly"}, {name: "Shemp"}] },
-  handlebars: "{{#each names}}{{@index}}{{name}}{{/each}}"
-}

bench/templates/depth-1.js

@@ -1,6 +0,0 @@
-module.exports = {
-  context: { names: [{name: "Moe"}, {name: "Larry"}, {name: "Curly"}, {name: "Shemp"}], foo: 'bar' },
-  handlebars: "{{#each names}}{{../foo}}{{/each}}",
-  mustache: "{{#names}}{{foo}}{{/names}}",
-  eco: "<% for item in @names: %><%= @foo %><% end %>"
-};

bench/templates/depth-2.js

@@ -1,6 +0,0 @@
-module.exports = {
-  context: { names: [{bat: 'foo', name: ["Moe"]}, {bat: 'foo', name: ["Larry"]}, {bat: 'foo', name: ["Curly"]}, {bat: 'foo', name: ["Shemp"]}], foo: 'bar' },
-  handlebars: "{{#each names}}{{#each name}}{{../bat}}{{../../foo}}{{/each}}{{/each}}",
-  mustache: "{{#names}}{{#name}}{{bat}}{{foo}}{{/name}}{{/names}}",
-  eco: "<% for item in @names: %><% for child in item.name: %><%= item.bat %><%= @foo %><% end %><% end %>"
-};

bench/templates/index.js

@@ -1,9 +0,0 @@
-var fs = require('fs');
-
-var templates = fs.readdirSync(__dirname);
-templates.forEach(function(template) {
-  if (template === 'index.js' || !/(.*)\.js$/.test(template)) {
-    return;
-  }
-  module.exports[RegExp.$1] = require('./' + RegExp.$1);
-});

bench/templates/object-mustache.js

@@ -1,4 +0,0 @@
-module.exports = {
-  context: { person: { name: "Larry", age: 45 } },
-  handlebars: "{{#person}}{{name}}{{age}}{{/person}}"
-};

bench/templates/object.js

@@ -1,7 +0,0 @@
-module.exports = {
-  context: { person: { name: "Larry", age: 45 } },
-  handlebars: "{{#with person}}{{name}}{{age}}{{/with}}",
-  dust: "{#person}{name}{age}{/person}",
-  eco: "<%= @person.name %><%= @person.age %>",
-  mustache: "{{#person}}{{name}}{{age}}{{/person}}"
-};

bench/templates/partial-recursion.js

@@ -1,10 +0,0 @@
-module.exports = {
-  context: { name: '1', kids: [{ name: '1.1', kids: [{name: '1.1.1', kids: []}] }] },
-  partials: {
-    mustache: { recursion: "{{name}}{{#kids}}{{>recursion}}{{/kids}}" },
-    handlebars: { recursion: "{{name}}{{#each kids}}{{>recursion}}{{/each}}" }
-  },
-  handlebars: "{{name}}{{#each kids}}{{>recursion}}{{/each}}",
-  dust: "{name}{#kids}{>recursion:./}{/kids}",
-  mustache: "{{name}}{{#kids}}{{>recursion}}{{/kids}}"
-};

bench/templates/partial.js

@@ -1,11 +0,0 @@
-module.exports = {
-  context: { peeps: [{name: "Moe", count: 15}, {name: "Larry", count: 5}, {name: "Curly", count: 1}] },
-  partials: {
-    mustache: { variables: "Hello {{name}}! You have {{count}} new messages." },
-    handlebars: { variables: "Hello {{name}}! You have {{count}} new messages." }
-  },
-
-  handlebars: "{{#each peeps}}{{>variables}}{{/each}}",
-  dust: "{#peeps}{>variables/}{/peeps}",
-  mustache: "{{#peeps}}{{>variables}}{{/peeps}}"
-};

bench/templates/paths.js

@@ -1,7 +0,0 @@
-module.exports = {
-  context: { person: { name: "Larry", age: 45 } },
-  handlebars: "{{person.name}}{{person.age}}{{person.foo}}{{animal.age}}",
-  dust: "{person.name}{person.age}{person.foo}{animal.age}",
-  eco: "<%= @person.name %><%= @person.age %><%= @person.foo %><% if @animal: %><%= @animal.age %><% end %>",
-  mustache: "{{person.name}}{{person.age}}{{person.foo}}{{animal.age}}"
-};

bench/templates/string.js

@@ -1,7 +0,0 @@
-module.exports = {
-  context: {},
-  handlebars: "Hello world",
-  dust: "Hello world",
-  mustache: "Hello world",
-  eco: "Hello world"
-};

bench/templates/subexpression.js

@@ -1,14 +0,0 @@
-module.exports = {
-  helpers: {
-    echo: function(value) {
-      return 'foo ' + value;
-    },
-    header: function() {
-      return "Colors";
-    }
-  },
-  handlebars: "{{echo (header)}}",
-  eco: "<%= @echo(@header()) %>"
-};
-
-module.exports.context = module.exports.helpers;

bench/templates/variables.js

@@ -1,8 +0,0 @@
-module.exports = {
-  context: {name: "Mick", count: 30},
-  handlebars:  "Hello {{name}}! You have {{count}} new messages.",
-  dust: "Hello {name}! You have {count} new messages.",
-  mustache: "Hello {{name}}! You have {{count}} new messages.",
-  eco: "Hello <%= @name %>! You have <%= @count %> new messages."
-};
-

bench/throughput.js

@@ -1,123 +0,0 @@
-var _ = require('underscore'),
-    runner = require('./util/template-runner'),
-    templates = require('./templates'),
-
-    eco, dust, Handlebars, Mustache, eco;
-
-try {
-  dust = require("dustjs-linkedin");
-} catch (err) { /* NOP */ }
-
-try {
-  Mustache = require("mustache");
-} catch (err) { /* NOP */ }
-
-try {
-  eco = require("eco");
-} catch (err) { /* NOP */ }
-
-function error() {
-  throw new Error("EWOT");
-}
-
-function makeSuite(bench, name, template, handlebarsOnly) {
-  // Create aliases to minimize any impact from having to walk up the closure tree.
-  var templateName = name,
-
-      context = template.context,
-      partials = template.partials,
-
-      handlebarsOut,
-      dustOut,
-      ecoOut,
-      mustacheOut;
-
-  var handlebar = Handlebars.compile(template.handlebars, {data: false}),
-      options = {helpers: template.helpers};
-  _.each(template.partials && template.partials.handlebars, function(partial, name) {
-    Handlebars.registerPartial(name, Handlebars.compile(partial, {data: false}));
-  });
-
-  handlebarsOut = handlebar(context, options);
-  bench("handlebars", function() {
-    handlebar(context, options);
-  });
-
-  if (handlebarsOnly) {
-    return;
-  }
-
-  if (dust) {
-    if (template.dust) {
-      dustOut = false;
-      dust.loadSource(dust.compile(template.dust, templateName));
-
-      dust.render(templateName, context, function(err, out) { dustOut = out; });
-
-      bench("dust", function() {
-        dust.render(templateName, context, function(err, out) { });
-      });
-    } else {
-      bench('dust', error);
-    }
-  }
-
-  if (eco) {
-    if (template.eco) {
-      var ecoTemplate = eco.compile(template.eco);
-
-      ecoOut = ecoTemplate(context);
-
-      bench("eco", function() {
-        ecoTemplate(context);
-      });
-    } else {
-      bench("eco", error);
-    }
-  }
-
-  if (Mustache) {
-    var mustacheSource = template.mustache,
-        mustachePartials = partials && partials.mustache;
-
-    if (mustacheSource) {
-      mustacheOut = Mustache.to_html(mustacheSource, context, mustachePartials);
-
-      bench("mustache", function() {
-        Mustache.to_html(mustacheSource, context, mustachePartials);
-      });
-    } else {
-      bench("mustache", error);
-    }
-  }
-
-  // Hack around whitespace until we have whitespace control
-  handlebarsOut = handlebarsOut.replace(/\s/g, '');
-  function compare(b, lang) {
-    if (b == null) {
-      return;
-    }
-
-    b = b.replace(/\s/g, '');
-
-    if (handlebarsOut !== b) {
-      throw new Error('Template output mismatch: ' + name
-            + '\n\nHandlebars: ' + handlebarsOut
-            + '\n\n' + lang + ': ' + b);
-    }
-  }
-
-  compare(dustOut, 'dust');
-  compare(ecoOut, 'eco');
-  compare(mustacheOut, 'mustache');
-}
-
-module.exports = function(grunt, callback) {
-  // Deferring load incase we are being run inline with the grunt build
-  Handlebars = require('../lib');
-
-  console.log('Execution Throughput');
-  runner(grunt, makeSuite, function(times, scaled) {
-    callback(scaled);
-  });
-};

bench/util/benchwarmer.js

@@ -1,199 +0,0 @@
-var _ = require('underscore'),
-    Benchmark = require("benchmark");
-
-var BenchWarmer = function(names) {
-  this.benchmarks = [];
-  this.currentBenches = [];
-  this.names = [];
-  this.times = {};
-  this.minimum = Infinity;
-  this.maximum = -Infinity;
-  this.errors = {};
-};
-
-var print = require("sys").print;
-
-BenchWarmer.prototype = {
-  winners: function(benches) {
-    return Benchmark.filter(benches, 'fastest');
-  },
-  suite: function(suite, fn) {
-    this.suiteName = suite;
-    this.times[suite] = {};
-    this.first = true;
-
-    var self = this;
-
-    fn(function(name, benchFn) {
-      self.push(name, benchFn);
-    });
-  },
-  push: function(name, fn) {
-    if(this.names.indexOf(name) == -1) {
-      this.names.push(name);
-    }
-
-    var first = this.first, suiteName = this.suiteName, self = this;
-    this.first = false;
-
-    var bench = new Benchmark(fn, {
-      name: this.suiteName + ": " + name,
-      onComplete: function() {
-        if(first) { self.startLine(suiteName); }
-        self.writeBench(bench);
-        self.currentBenches.push(bench);
-      }, onError: function() {
-        self.errors[this.name] = this;
-      }
-    });
-    bench.suiteName = this.suiteName;
-    bench.benchName = name;
-
-    this.benchmarks.push(bench);
-  },
-
-  bench: function(callback) {
-    var self = this;
-
-    this.printHeader('ops/msec', true);
-
-    Benchmark.invoke(this.benchmarks, {
-      name: "run",
-      onComplete: function() {
-        self.scaleTimes();
-
-        self.startLine('');
-
-        print('\n');
-        self.printHeader('scaled');
-        _.each(self.scaled, function(value, name) {
-          self.startLine(name);
-
-          _.each(self.names, function(lang) {
-            self.writeValue(value[lang] || '');
-          });
-        });
-        print('\n');
-
-        var errors = false, prop, bench;
-        for(prop in self.errors) {
-          if (self.errors.hasOwnProperty(prop)
-              && self.errors[prop].error.message !== 'EWOT') {
-            errors = true;
-            break;
-          }
-        }
-
-        if(errors) {
-          print("\n\nErrors:\n");
-          for(prop in self.errors) {
-            if (self.errors.hasOwnProperty(prop)
-                && self.errors[prop].error.message !== 'EWOT') {
-              bench = self.errors[prop];
-              print("\n" + bench.name + ":\n");
-              print(bench.error.message);
-              if(bench.error.stack) {
-                print(bench.error.stack.join("\n"));
-              }
-              print("\n");
-            }
-          }
-        }
-
-        callback();
-      }
-    });
-
-    print("\n");
-  },
-
-  scaleTimes: function() {
-    var scaled = this.scaled = {};
-    _.each(this.times, function(times, name) {
-      var output = scaled[name] = {};
-
-      _.each(times, function(time, lang) {
-        output[lang] = ((time - this.minimum) / (this.maximum - this.minimum) * 100).toFixed(2);
-      }, this);
-    }, this);
-  },
-
-  printHeader: function(title, winners) {
-    var benchSize = 0, names = this.names, i, l;
-
-    for(i=0, l=names.length; i<l; i++) {
-      var name = names[i];
-
-      if(benchSize < name.length) { benchSize = name.length; }
-    }
-
-    this.nameSize = benchSize + 2;
-    this.benchSize = 20;
-    var horSize = 0;
-
-    this.startLine(title);
-    horSize = horSize + this.benchSize;
-    for(i=0, l=names.length; i<l; i++) {
-      this.writeValue(names[i]);
-      horSize = horSize + this.benchSize;
-    }
-
-    if (winners) {
-      print("WINNER(S)");
-      horSize = horSize + "WINNER(S)".length;
-    }
-
-    print("\n" + new Array(horSize + 1).join("-"));
-  },
-
-  startLine: function(name) {
-    var winners = Benchmark.map(this.winners(this.currentBenches), function(bench) {
-      return bench.name.split(": ")[1];
-    });
-
-    this.currentBenches = [];
-
-    print(winners.join(", "));
-    print("\n");
-
-    if (name) {
-      this.writeValue(name);
-    }
-  },
-  writeBench: function(bench) {
-    var out;
-
-    if(!bench.error) {
-      var count = bench.hz,
-          moe   = count * bench.stats.rme / 100,
-          minimum,
-          maximum;
-
-      count = Math.round(count / 1000);
-      moe = Math.round(moe / 1000);
-      minimum = count - moe;
-      maximum = count + moe;
-
-      out = count + " ±" + moe + " (" + bench.cycles + ")";
-
-      this.times[bench.suiteName][bench.benchName] = count;
-      this.minimum = Math.min(this.minimum, minimum);
-      this.maximum = Math.max(this.maximum, maximum);
-    } else {
-      if (bench.error.message === 'EWOT') {
-        out = 'NA';
-      } else {
-        out = 'E';
-      }
-    }
-    this.writeValue(out);
-  },
-
-  writeValue: function(out) {
-    var padding = this.benchSize - out.length + 1;
-    out = out + new Array(padding).join(" ");
-    print(out);
-  }
-};
-
-module.exports = BenchWarmer;

bench/util/template-runner.js

@@ -1,27 +0,0 @@
-var _ = require('underscore'),
-    BenchWarmer = require('./benchwarmer'),
-    templates = require('../templates');
-
-module.exports = function(grunt, makeSuite, callback) {
-  var warmer = new BenchWarmer();
-
-  var handlebarsOnly = grunt.option('handlebars-only'),
-      grep = grunt.option('grep');
-  if (grep) {
-    grep = new RegExp(grep);
-  }
-
-  _.each(templates, function(template, name) {
-    if (!template.handlebars || (grep && !grep.test(name))) {
-      return;
-    }
-
-    warmer.suite(name, function(bench) {
-      makeSuite(bench, name, template, handlebarsOnly);
-    });
-  });
-
-  warmer.bench(function() {
-    callback && callback(warmer.times, warmer.scaled);
-  });
-};

bin/handlebars

@@ -1,235 +0,0 @@
-#!/usr/bin/env node
-
-var optimist = require('optimist')
-    .usage('Precompile handlebar templates.\nUsage: $0 template...', {
-      'f': {
-        'type': 'string',
-        'description': 'Output File',
-        'alias': 'output'
-      },
-      'a': {
-        'type': 'boolean',
-        'description': 'Exports amd style (require.js)',
-        'alias': 'amd'
-      },
-      'c': {
-        'type': 'string',
-        'description': 'Exports CommonJS style, path to Handlebars module',
-        'alias': 'commonjs',
-        'default': null
-      },
-      'h': {
-        'type': 'string',
-        'description': 'Path to handlebar.js (only valid for amd-style)',
-        'alias': 'handlebarPath',
-		    'default': ''
-      },
-      'k': {
-        'type': 'string',
-        'description': 'Known helpers',
-        'alias': 'known'
-      },
-      'o': {
-        'type': 'boolean',
-        'description': 'Known helpers only',
-        'alias': 'knownOnly'
-      },
-      'm': {
-        'type': 'boolean',
-        'description': 'Minimize output',
-        'alias': 'min'
-      },
-      'n': {
-        'type': 'string',
-        'description': 'Template namespace',
-        'alias': 'namespace',
-        'default': 'Handlebars.templates'
-      },
-      's': {
-        'type': 'boolean',
-        'description': 'Output template function only.',
-        'alias': 'simple'
-      },
-      'r': {
-        'type': 'string',
-        'description': 'Template root. Base value that will be stripped from template names.',
-        'alias': 'root'
-      },
-      'p' : {
-        'type': 'boolean',
-        'description': 'Compiling a partial template',
-        'alias': 'partial'
-      },
-      'd' : {
-        'type': 'boolean',
-        'description': 'Include data when compiling',
-        'alias': 'data'
-      },
-      'e': {
-        'type': 'string',
-        'description': 'Template extension.',
-        'alias': 'extension',
-        'default': 'handlebars'
-      },
-      'b': {
-        'type': 'boolean',
-        'description': 'Removes the BOM (Byte Order Mark) from the beginning of the templates.',
-        'alias': 'bom'
-      },
-      'v': {
-        'type': 'boolean',
-        'description': 'Prints the current compiler version',
-        'alias': 'version'
-      }
-    })
-
-    .check(function(argv) {
-      if (argv.version) {
-        return;
-      }
-
-      var template = [0];
-      if (!argv._.length) {
-        throw 'Must define at least one template or directory.';
-      }
-
-      argv._.forEach(function(template) {
-        try {
-          fs.statSync(template);
-        } catch (err) {
-          throw 'Unable to open template file "' + template + '"';
-        }
-      });
-    })
-    .check(function(argv) {
-      if (argv.simple && argv.min) {
-        throw 'Unable to minimze simple output';
-      }
-      if (argv.simple && (argv._.length !== 1 || fs.statSync(argv._[0]).isDirectory())) {
-        throw 'Unable to output multiple templates in simple mode';
-      }
-    });
-
-var fs = require('fs'),
-    handlebars = require('../lib'),
-    basename = require('path').basename,
-    uglify = require('uglify-js');
-
-var argv = optimist.argv,
-    template = argv._[0];
-
-if (argv.version) {
-  return console.log(handlebars.VERSION);
-}
-
-// Convert the known list into a hash
-var known = {};
-if (argv.known && !Array.isArray(argv.known)) {
-  argv.known = [argv.known];
-}
-if (argv.known) {
-  for (var i = 0, len = argv.known.length; i < len; i++) {
-    known[argv.known[i]] = true;
-  }
-}
-
-// Build file extension pattern
-var extension = argv.extension.replace(/[\\^$*+?.():=!|{}\-\[\]]/g, function(arg) { return '\\' + arg; });
-extension = new RegExp('\\.' + extension + '$');
-
-var output = [];
-if (!argv.simple) {
-  if (argv.amd) {
-    output.push('define([\'' + argv.handlebarPath + 'handlebars.runtime\'], function(Handlebars) {\n  Handlebars = Handlebars["default"];');
-  } else if (argv.commonjs) {
-    output.push('var Handlebars = require("' + argv.commonjs + '");');
-  } else {
-    output.push('(function() {\n');
-  }
-  output.push('  var template = Handlebars.template, templates = ');
-  output.push(argv.namespace);
-  output.push(' = ');
-  output.push(argv.namespace);
-  output.push(' || {};\n');
-}
-function processTemplate(template, root, explicit) {
-  var path = template,
-      stat = fs.statSync(path);
-  if (stat.isDirectory()) {
-    fs.readdirSync(template).map(function(file) {
-      var path = template + '/' + file;
-
-      if (extension.test(path) || fs.statSync(path).isDirectory()) {
-        processTemplate(path, root || template);
-      }
-    });
-  } else if (explicit || extension.test(path)) {
-    var data = fs.readFileSync(path, 'utf8');
-
-    if (argv.bom && data.indexOf('\uFEFF') === 0) {
-      data = data.substring(1);
-    }
-
-    var options = {
-      knownHelpers: known,
-      knownHelpersOnly: argv.o
-    };
-
-    if (argv.data) {
-      options.data = true;
-    }
-
-    // Clean the template name
-    if (!root) {
-      template = basename(template);
-    } else if (template.indexOf(root) === 0) {
-      template = template.substring(root.length+1);
-    }
-    template = template.replace(extension, '');
-
-    if (argv.simple) {
-      output.push(handlebars.precompile(data, options) + '\n');
-    } else if (argv.partial) {
-      if(argv.amd && (argv._.length == 1 && !fs.statSync(argv._[0]).isDirectory())) {
-        output.push('return ');
-      }
-      output.push('Handlebars.partials[\'' + template + '\'] = template(' + handlebars.precompile(data, options) + ');\n');
-    } else {
-      if(argv.amd && (argv._.length == 1 && !fs.statSync(argv._[0]).isDirectory())) {
-        output.push('return ');
-      }
-      output.push('templates[\'' + template + '\'] = template(' + handlebars.precompile(data, options) + ');\n');
-    }
-  }
-}
-
-argv._.forEach(function(template) {
-  processTemplate(template, argv.root, true);
-});
-
-// Output the content
-if (!argv.simple) {
-  if (argv.amd) {
-    if(argv._.length > 1 || (argv._.length == 1 && fs.statSync(argv._[0]).isDirectory())) {
-      if(argv.partial){
-        output.push('return Handlebars.partials;\n');
-      } else {
-        output.push('return templates;\n');
-      }
-    }
-    output.push('});');
-  } else if (!argv.commonjs) {
-    output.push('})();');
-  }
-}
-output = output.join('');
-
-if (argv.min) {
-  output = uglify.minify(output, {fromString: true}).code;
-}
-
-if (argv.output) {
-  fs.writeFileSync(argv.output, output, 'utf8');
-} else {
-  console.log(output);
-}

bin/handlebars.mjs

@@ -0,0 +1,136 @@
+#!/usr/bin/env node
+
+import { createRequire } from 'node:module';
+import yargs from 'yargs';
+
+const require = createRequire(import.meta.url);
+const Precompiler = require('../dist/cjs/precompiler');
+
+const parser = yargs(process.argv.slice(2))
+  .usage('Precompile handlebar templates.\nUsage: $0 [template|directory]...')
+  .help(false)
+  .version(false)
+  .option('f', {
+    type: 'string',
+    description: 'Output File',
+    alias: 'output',
+  })
+  .option('map', {
+    type: 'string',
+    description: 'Source Map File',
+  })
+  .option('a', {
+    type: 'boolean',
+    description: 'Exports amd style (require.js)',
+    alias: 'amd',
+  })
+  .option('c', {
+    type: 'string',
+    description: 'Exports CommonJS style, path to Handlebars module',
+    alias: 'commonjs',
+    default: null,
+  })
+  .option('h', {
+    type: 'string',
+    description: 'Path to handlebar.js (only valid for amd-style)',
+    alias: 'handlebarPath',
+    default: '',
+  })
+  .option('k', {
+    type: 'string',
+    description: 'Known helpers',
+    alias: 'known',
+  })
+  .option('o', {
+    type: 'boolean',
+    description: 'Known helpers only',
+    alias: 'knownOnly',
+  })
+  .option('m', {
+    type: 'boolean',
+    description: 'Minimize output',
+    alias: 'min',
+  })
+  .option('n', {
+    type: 'string',
+    description: 'Template namespace',
+    alias: 'namespace',
+    default: 'Handlebars.templates',
+  })
+  .option('s', {
+    type: 'boolean',
+    description: 'Output template function only.',
+    alias: 'simple',
+  })
+  .option('N', {
+    type: 'string',
+    description:
+      'Name of passed string templates. Optional if running in a simple mode. Required when operating on multiple templates.',
+    alias: 'name',
+  })
+  .option('i', {
+    type: 'string',
+    description:
+      'Generates a template from the passed CLI argument.\n"-" is treated as a special value and causes stdin to be read for the template value.',
+    alias: 'string',
+  })
+  .option('r', {
+    type: 'string',
+    description:
+      'Template root. Base value that will be stripped from template names.',
+    alias: 'root',
+  })
+  .option('p', {
+    type: 'boolean',
+    description: 'Compiling a partial template',
+    alias: 'partial',
+  })
+  .option('d', {
+    type: 'boolean',
+    description: 'Include data when compiling',
+    alias: 'data',
+  })
+  .option('e', {
+    type: 'string',
+    description: 'Template extension.',
+    alias: 'extension',
+    default: 'handlebars',
+  })
+  .option('b', {
+    type: 'boolean',
+    description:
+      'Removes the BOM (Byte Order Mark) from the beginning of the templates.',
+    alias: 'bom',
+  })
+  .option('v', {
+    type: 'boolean',
+    description: 'Prints the current compiler version',
+    alias: 'version',
+  })
+  .option('help', {
+    type: 'boolean',
+    description: 'Outputs this message',
+  })
+  .wrap(120);
+
+const argv = parser.parseSync();
+argv.files = argv._;
+delete argv._;
+
+Precompiler.loadTemplates(argv, function (err, opts) {
+  if (err) {
+    throw err;
+  }
+
+  if (opts.help || (!opts.templates.length && !opts.version)) {
+    parser.showHelp('log');
+  } else {
+    // cli() is async (returns a Promise), so errors would become unhandled
+    // rejections. Re-throw via nextTick to surface them as uncaught exceptions.
+    Promise.resolve(Precompiler.cli(opts)).catch((error) => {
+      process.nextTick(() => {
+        throw error;
+      });
+    });
+  }
+});

components/bower.json

@@ -1,6 +1,7 @@
 {
   "name": "handlebars",
-  "version": "2.0.0-alpha.4",
+  "version": "5.0.0-alpha.1",
   "main": "handlebars.js",
+  "license": "MIT",
   "dependencies": {}
 }

components/component.json

@@ -3,7 +3,5 @@
   "repo": "components/handlebars.js",
   "version": "1.0.0",
   "main": "handlebars.js",
-  "scripts": [
-    "handlebars.js"
-  ]
+  "scripts": ["handlebars.js"]
 }

components/composer.json

@@ -1,35 +1,35 @@
 {
-    "name": "components/handlebars.js",
-    "description": "Handlebars.js and Mustache are both logicless templating languages that keep the view and the code separated like we all know they should be.",
-    "homepage": "http://handlebarsjs.com",
-    "license": "MIT",
-    "type": "component",
-    "keywords": [
-        "handlebars",
-        "mustache",
-        "html"
-    ],
-    "authors": [
-        {
-            "name": "Chris Wanstrath",
-            "homepage": "http://chriswanstrath.com"
-        }
-    ],
-    "require": {
-        "robloach/component-installer": "*"
-    },
-    "extra": {
-        "component": {
-            "name": "handlebars",
-            "scripts": [
-                "handlebars.js"
-            ],
-            "files": [
-                "handlebars.runtime.js"
-            ],
-            "shim": {
-                "exports": "Handlebars"
-            }
-        }
+  "name": "components/handlebars.js",
+  "description": "Handlebars.js and Mustache are both logicless templating languages that keep the view and the code separated like we all know they should be.",
+  "homepage": "http://handlebarsjs.com",
+  "license": "MIT",
+  "type": "component",
+  "keywords": [
+    "handlebars",
+    "mustache",
+    "html"
+  ],
+  "authors": [
+    {
+      "name": "Chris Wanstrath",
+      "homepage": "http://chriswanstrath.com"
     }
+  ],
+  "require": {
+    "robloach/component-installer": "*"
+  },
+  "extra": {
+    "component": {
+      "name": "handlebars",
+      "scripts": [
+        "handlebars.js"
+      ],
+      "files": [
+        "handlebars.runtime.js"
+      ],
+      "shim": {
+        "exports": "Handlebars"
+      }
+    }
+  }
 }

components/handlebars-source.gemspec

@@ -10,8 +10,8 @@ Gem::Specification.new do |gem|
   gem.date          = Time.now.strftime("%Y-%m-%d")
   gem.description   = %q{Handlebars.js source code wrapper for (pre)compilation gems.}
   gem.summary       = %q{Handlebars.js source code wrapper}
-  gem.homepage      = "https://github.com/wycats/handlebars.js/"
-  gem.version       = package["version"]
+  gem.homepage      = "https://github.com/handlebars-lang/handlebars.js/"
+  gem.version       = package["version"].sub "-", "."
   gem.license       = "MIT"
 
   gem.files = [

components/handlebars.js.nuspec

@@ -2,10 +2,10 @@
 <package>
 	<metadata>
 		<id>handlebars.js</id>
-		<version>2.0.0-alpha.4</version>
+		<version>5.0.0-alpha.1</version>
 		<authors>handlebars.js Authors</authors>
-		<licenseUrl>https://github.com/wycats/handlebars.js/blob/master/LICENSE</licenseUrl>
-		<projectUrl>https://github.com/wycats/handlebars.js/</projectUrl>
+		<licenseUrl>https://github.com/handlebars-lang/handlebars.js/blob/master/LICENSE</licenseUrl>
+		<projectUrl>https://github.com/handlebars-lang/handlebars.js/</projectUrl>
 		<requireLicenseAcceptance>false</requireLicenseAcceptance>
 		<description>Extension of the Mustache logicless template language</description>
 		<releaseNotes></releaseNotes>

components/package.json

@@ -0,0 +1,20 @@
+{
+  "name": "handlebars",
+  "version": "5.0.0-alpha.1",
+  "license": "MIT",
+  "jspm": {
+    "main": "handlebars",
+    "shim": {
+      "handlebars": {
+        "exports": "Handlebars"
+      }
+    },
+    "files": [
+      "handlebars.js",
+      "handlebars.runtime.js"
+    ],
+    "buildConfig": {
+      "minify": true
+    }
+  }
+}

docs/compiler-api.md

@@ -0,0 +1,365 @@
+# Handlebars Compiler APIs
+
+There are a number of formal APIs that tool implementors may interact with.
+
+## AST
+
+Other tools may interact with the formal AST as defined below. Any JSON structure matching this pattern may be used and passed into the `compile` and `precompile` methods in the same way as the text for a template.
+
+AST structures may be generated either with the `Handlebars.parse` method and then manipulated, via the `Handlebars.AST` objects of the same name, or constructed manually as a generic JavaScript object matching the structure defined below.
+
+```javascript
+var ast = Handlebars.parse(myTemplate);
+
+// Modify ast
+
+Handlebars.precompile(ast);
+```
+
+### Parsing
+
+There are two primary APIs that are used to parse an existing template into the AST:
+
+#### parseWithoutProcessing
+
+`Handlebars.parseWithoutProcessing` is the primary mechanism to turn a raw template string into the Handlebars AST described in this document. No processing is done on the resulting AST which makes this ideal for codemod (for source to source transformation) tooling.
+
+Example:
+
+```js
+let ast = Handlebars.parseWithoutProcessing(myTemplate);
+```
+
+#### parse
+
+`Handlebars.parse` will parse the template with `parseWithoutProcessing` (see above) then it will update the AST to strip extraneous whitespace. The whitespace stripping functionality handles two distinct situations:
+
+- Removes whitespace around dynamic statements that are on a line by themselves (aka "stand alone")
+- Applies "whitespace control" characters (i.e. `~`) by truncating the `ContentStatement` `value` property appropriately (e.g. `\n\n{{~foo}}` would have a `ContentStatement` with a `value` of `''`)
+
+`Handlebars.parse` is used internally by `Handlebars.precompile` and `Handlebars.compile`.
+
+Example:
+
+```js
+let ast = Handlebars.parse(myTemplate);
+```
+
+### Basic
+
+```java
+interface Node {
+    type: string;
+    loc: SourceLocation | null;
+}
+
+interface SourceLocation {
+    source: string | null;
+    start: Position;
+    end: Position;
+}
+
+interface Position {
+    line: uint >= 1;
+    column: uint >= 0;
+}
+```
+
+### Programs
+
+```java
+interface Program <: Node {
+    type: "Program";
+    body: [ Statement ];
+
+    blockParams: [ string ];
+}
+```
+
+### Statements
+
+```java
+interface Statement <: Node { }
+
+interface MustacheStatement <: Statement {
+    type: "MustacheStatement";
+
+    path: PathExpression | Literal;
+    params: [ Expression ];
+    hash: Hash;
+
+    escaped: boolean;
+    strip: StripFlags | null;
+}
+
+interface BlockStatement <: Statement {
+    type: "BlockStatement";
+    path: PathExpression | Literal;
+    params: [ Expression ];
+    hash: Hash;
+
+    program: Program | null;
+    inverse: Program | null;
+
+    openStrip: StripFlags | null;
+    inverseStrip: StripFlags | null;
+    closeStrip: StripFlags | null;
+}
+
+interface PartialStatement <: Statement {
+    type: "PartialStatement";
+    name: PathExpression | SubExpression;
+    params: [ Expression ];
+    hash: Hash;
+
+    indent: string;
+    strip: StripFlags | null;
+}
+
+interface PartialBlockStatement <: Statement {
+    type: "PartialBlockStatement";
+    name: PathExpression | SubExpression;
+    params: [ Expression ];
+    hash: Hash;
+
+    program: Program | null;
+
+    indent: string;
+    openStrip: StripFlags | null;
+    closeStrip: StripFlags | null;
+}
+```
+
+`name` will be a `SubExpression` when tied to a dynamic partial, i.e. `{{> (foo) }}`, otherwise this is a path or literal whose `original` value is used to lookup the desired partial.
+
+```java
+interface ContentStatement <: Statement {
+    type: "ContentStatement";
+    value: string;
+    original: string;
+}
+
+interface CommentStatement <: Statement {
+    type: "CommentStatement";
+    value: string;
+
+    strip: StripFlags | null;
+}
+```
+
+```java
+interface Decorator <: Statement {
+    type: "Decorator";
+
+    path: PathExpression | Literal;
+    params: [ Expression ];
+    hash: Hash;
+
+    strip: StripFlags | null;
+}
+
+interface DecoratorBlock <: Statement {
+    type: "DecoratorBlock";
+    path: PathExpression | Literal;
+    params: [ Expression ];
+    hash: Hash;
+
+    program: Program | null;
+
+    openStrip: StripFlags | null;
+    closeStrip: StripFlags | null;
+}
+```
+
+Decorator paths only utilize the `path.original` value and as a consequence do not support depthed evaluation.
+
+### Expressions
+
+```java
+interface Expression <: Node { }
+```
+
+##### SubExpressions
+
+```java
+interface SubExpression <: Expression {
+    type: "SubExpression";
+    path: PathExpression;
+    params: [ Expression ];
+    hash: Hash;
+}
+```
+
+##### Paths
+
+```java
+interface PathExpression <: Expression {
+    type: "PathExpression";
+    data: boolean;
+    depth: uint >= 0;
+    parts: [ string ];
+    original: string;
+}
+```
+
+- `data` is true when the given expression is a `@data` reference.
+- `depth` is an integer representation of which context the expression references. `0` represents the current context, `1` would be `../`, etc.
+- `parts` is an array of the names in the path. `foo.bar` would be `['foo', 'bar']`. Scope references, `.`, `..`, and `this` should be omitted from this array.
+- `original` is the path as entered by the user. Separator and scope references are left untouched.
+
+##### Literals
+
+```java
+interface Literal <: Expression { }
+
+interface StringLiteral <: Literal {
+    type: "StringLiteral";
+    value: string;
+    original: string;
+}
+
+interface BooleanLiteral <: Literal {
+    type: "BooleanLiteral";
+    value: boolean;
+    original: boolean;
+}
+
+interface NumberLiteral <: Literal {
+    type: "NumberLiteral";
+    value: number;
+    original: number;
+}
+
+interface UndefinedLiteral <: Literal {
+    type: "UndefinedLiteral";
+}
+
+interface NullLiteral <: Literal {
+    type: "NullLiteral";
+}
+```
+
+### Miscellaneous
+
+```java
+interface Hash <: Node {
+    type: "Hash";
+    pairs: [ HashPair ];
+}
+
+interface HashPair <: Node {
+    type: "HashPair";
+    key: string;
+    value: Expression;
+}
+
+interface StripFlags {
+    open: boolean;
+    close: boolean;
+}
+```
+
+`StripFlags` are used to signify whitespace control character that may have been entered on a given statement.
+
+## AST Visitor
+
+`Handlebars.Visitor` is available as a base class for general interaction with AST structures. This will by default traverse the entire tree and individual methods may be overridden to provide specific responses to particular nodes.
+
+Recording all referenced partial names:
+
+```javascript
+var Visitor = Handlebars.Visitor;
+
+function ImportScanner() {
+  this.partials = [];
+}
+ImportScanner.prototype = new Visitor();
+
+ImportScanner.prototype.PartialStatement = function (partial) {
+  this.partials.push({ request: partial.name.original });
+
+  Visitor.prototype.PartialStatement.call(this, partial);
+};
+
+var scanner = new ImportScanner();
+scanner.accept(ast);
+```
+
+The current node's ancestors will be maintained in the `parents` array, with the most recent parent listed first.
+
+The visitor may also be configured to operate in mutation mode by setting the `mutating` field to true. When in this mode, handler methods may return any valid AST node and it will replace the one they are currently operating on. Returning `false` will remove the given value (if valid) and returning `undefined` will leave the node intact. This return structure only apply to mutation mode and non-mutation mode visitors are free to return whatever values they wish.
+
+Implementors that may need to support mutation mode are encouraged to utilize the `acceptKey`, `acceptRequired` and `acceptArray` helpers which provide the conditional overwrite behavior as well as implement sanity checks where pertinent.
+
+## JavaScript Compiler
+
+The `Handlebars.JavaScriptCompiler` object has a number of methods that may be customized to alter the output of the compiler:
+
+- `nameLookup(parent, name, type)`
+  Used to generate the code to resolve a given path component.
+  - `parent` is the existing code in the path resolution
+  - `name` is the current path component
+  - `type` is the type of name being evaluated. May be one of `context`, `data`, `helper`, `decorator`, or `partial`.
+
+  Note that this does not impact dynamic partials, which implementors need to be aware of. Overriding `VM.resolvePartial` may be required to support dynamic cases.
+
+- `depthedLookup(name)`
+  Used to generate code that resolves parameters within any context in the stack. Is only used in `compat` mode.
+
+- `compilerInfo()`
+  Allows for custom compiler flags used in the runtime version checking logic.
+
+- `appendToBuffer(source, location, explicit)`
+  Allows for code buffer emitting code. Defaults behavior is string concatenation.
+  - `source` is the source code whose result is to be appending
+  - `location` is the location of the source in the source map.
+  - `explicit` is a flag signaling that the emit operation must occur, vs. the lazy evaled options otherwise.
+
+- `initializeBuffer()`
+  Allows for buffers other than the default string buffer to be used. Generally needs to be paired with a custom `appendToBuffer` implementation.
+
+### Example for the compiler api.
+
+This example changes all lookups of properties are performed by a helper (`lookupLowerCase`) which looks for `test` if `{{Test}}` occurs in the template. This is just to illustrate how compiler behavior can be change.
+
+There is also [a jsfiddle with this code](https://jsfiddle.net/9D88g/162/) if you want to play around with it.
+
+```javascript
+function MyCompiler() {
+  Handlebars.JavaScriptCompiler.apply(this, arguments);
+}
+MyCompiler.prototype = new Handlebars.JavaScriptCompiler();
+
+// Use this compile to compile BlockStatment-Blocks
+MyCompiler.prototype.compiler = MyCompiler;
+
+MyCompiler.prototype.nameLookup = function (parent, name, type) {
+  if (type === 'context') {
+    return this.source.functionCall('helpers.lookupLowerCase', '', [
+      parent,
+      JSON.stringify(name),
+    ]);
+  } else {
+    return Handlebars.JavaScriptCompiler.prototype.nameLookup.call(
+      this,
+      parent,
+      name,
+      type
+    );
+  }
+};
+
+var env = Handlebars.create();
+env.registerHelper('lookupLowerCase', function (parent, name) {
+  return parent[name.toLowerCase()];
+});
+
+env.JavaScriptCompiler = MyCompiler;
+
+var template = env.compile('{{#each Test}} ({{Value}}) {{/each}}');
+console.log(
+  template({
+    test: [{ value: 'a' }, { value: 'b' }, { value: 'c' }],
+  })
+);
+```

docs/decorators-api.md

@@ -0,0 +1,21 @@
+# Decorators
+
+**Decorators are deprecated, please join the discussion at [#1574](https://github.com/handlebars-lang/handlebars.js/issues/1574) to see what we can do about it.**
+
+Decorators allow for blocks to be annotated with metadata or wrapped in functionality prior to execution of the block. This may be used to communicate with the containing helper or to set up a particular state in the system prior to running the block.
+
+Decorators are registered through similar methods as helpers, `registerDecorators` and `unregisterDecorators`. These can then be referenced via the friendly name in the template using the `{{* decorator}}` and `{{#* decorator}}{/decorator}}` syntaxes. These syntaxes are derivatives of the normal mustache syntax and as such have all of the same argument and whitespace behaviors.
+
+Decorators are executed when the block program is instantiated and are passed `(program, props, container, context, data, blockParams, depths)`.
+
+- `program`: The block to wrap
+- `props`: Object used to set metadata on the final function. Any values set on this object will be set on the function, regardless of if the original function is replaced or not. Metadata should be applied using this object as values applied to `program` may be masked by subsequent decorators that may wrap `program`.
+- `container`: The current runtime container
+- `context`: The current context. Since the decorator is run before the block that contains it, this is the parent context.
+- `data`: The current `@data` values
+- `blockParams`: The current block parameters stack
+- `depths`: The current context stack
+
+Decorators may set values on `props` or return a modified function that wraps `program` in particular behaviors. If the decorator returns nothing, then `program` is left unaltered.
+
+The [inline partial](https://github.com/handlebars-lang/handlebars.js/blob/master/lib/handlebars/decorators/inline.js) implementation provides an example of decorators being used for both metadata and wrapping behaviors.

eslint.config.mjs

@@ -0,0 +1,17 @@
+import compat from 'eslint-plugin-compat';
+
+export default [
+  {
+    // Ignore everything except lib/
+    ignores: ['**', '!lib/**'],
+  },
+  {
+    // Only check browser API compat in the runtime library code.
+    // All other linting is handled by oxlint.
+    ...compat.configs['flat/recommended'],
+    files: ['lib/**/*.js'],
+    linterOptions: {
+      reportUnusedDisableDirectives: 'off',
+    },
+  },
+];

lib/handlebars.js

@@ -1,17 +1,24 @@
-/*globals Handlebars: true */
-import Handlebars from "./handlebars.runtime";
+import {
+  parser as Parser,
+  parse,
+  parseWithoutProcessing,
+  Visitor,
+} from '@handlebars/parser';
+
+import runtime from './handlebars.runtime';
 
 // Compiler imports
-import AST from "./handlebars/compiler/ast";
-import { parser as Parser, parse } from "./handlebars/compiler/base";
-import { Compiler, compile, precompile } from "./handlebars/compiler/compiler";
-import JavaScriptCompiler from "./handlebars/compiler/javascript-compiler";
+import AST from './handlebars/compiler/ast';
+import { Compiler, compile, precompile } from './handlebars/compiler/compiler';
+import JavaScriptCompiler from './handlebars/compiler/javascript-compiler';
 
-var _create = Handlebars.create;
-var create = function() {
-  var hb = _create();
+import noConflict from './handlebars/no-conflict';
 
-  hb.compile = function(input, options) {
+let _create = runtime.create;
+function create() {
+  let hb = _create();
+
+  hb.compile = function (input, options) {
     return compile(input, options, hb);
   };
   hb.precompile = function (input, options) {
@@ -23,11 +30,18 @@ var create = function() {
   hb.JavaScriptCompiler = JavaScriptCompiler;
   hb.Parser = Parser;
   hb.parse = parse;
+  hb.parseWithoutProcessing = parseWithoutProcessing;
 
   return hb;
-};
+}
 
-Handlebars = create();
-Handlebars.create = create;
+let inst = create();
+inst.create = create;
 
-export default Handlebars;
+noConflict(inst);
+
+inst.Visitor = Visitor;
+
+inst['default'] = inst;
+
+export default inst;

lib/handlebars.runtime.js

@@ -1,31 +1,40 @@
-/*globals Handlebars: true */
-module base from "./handlebars/base";
+import { Exception } from '@handlebars/parser';
+import * as base from './handlebars/base';
 
 // Each of these augment the Handlebars object. No need to setup here.
 // (This is done to easily share code between commonjs and browse envs)
-import SafeString from "./handlebars/safe-string";
-import Exception from "./handlebars/exception";
-module Utils from "./handlebars/utils";
-module runtime from "./handlebars/runtime";
+import SafeString from './handlebars/safe-string';
+import * as Utils from './handlebars/utils';
+import * as runtime from './handlebars/runtime';
+
+import noConflict from './handlebars/no-conflict';
 
 // For compatibility and usage outside of module systems, make the Handlebars object a namespace
-var create = function() {
-  var hb = new base.HandlebarsEnvironment();
+function create() {
+  let hb = new base.HandlebarsEnvironment();
 
   Utils.extend(hb, base);
   hb.SafeString = SafeString;
   hb.Exception = Exception;
   hb.Utils = Utils;
+  hb.escapeExpression = Utils.escapeExpression;
 
-  hb.VM = runtime;
-  hb.template = function(spec) {
+  // Spread into a plain object so that runtime functions (e.g. checkRevision)
+  // can be overridden by consumers. ES module namespace objects are sealed with
+  // getter-only properties per spec, which would prevent monkey-patching.
+  hb.VM = { ...runtime };
+  hb.template = function (spec) {
     return runtime.template(spec, hb);
   };
 
   return hb;
-};
+}
 
-var Handlebars = create();
-Handlebars.create = create;
+let inst = create();
+inst.create = create;
 
-export default Handlebars;
+noConflict(inst);
+
+inst['default'] = inst;
+
+export default inst;

lib/handlebars/base.js

@@ -1,230 +1,94 @@
-module Utils from "./utils";
-import Exception from "./exception";
+import { Exception } from '@handlebars/parser';
+import { createFrame, extend, toString } from './utils';
+import { registerDefaultHelpers } from './helpers';
+import { registerDefaultDecorators } from './decorators';
+import logger from './logger';
+import { resetLoggedProperties } from './internal/proto-access';
 
-export var VERSION = "2.0.0-alpha.4";
-export var COMPILER_REVISION = 5;
+export const VERSION = '4.7.7';
+export const COMPILER_REVISION = 8;
+export const LAST_COMPATIBLE_COMPILER_REVISION = 7;
 
-export var REVISION_CHANGES = {
+export const REVISION_CHANGES = {
   1: '<= 1.0.rc.2', // 1.0.rc.2 is actually rev2 but doesn't report it
   2: '== 1.0.0-rc.3',
   3: '== 1.0.0-rc.4',
   4: '== 1.x.x',
-  5: '>= 2.0.0'
+  5: '== 2.0.0-alpha.x',
+  6: '>= 2.0.0-beta.1',
+  7: '>= 4.0.0 <4.3.0',
+  8: '>= 4.3.0',
 };
 
-var isArray = Utils.isArray,
-    isFunction = Utils.isFunction,
-    toString = Utils.toString,
-    objectType = '[object Object]';
+const objectType = '[object Object]';
 
-export function HandlebarsEnvironment(helpers, partials) {
+export function HandlebarsEnvironment(helpers, partials, decorators) {
   this.helpers = helpers || {};
   this.partials = partials || {};
+  this.decorators = decorators || {};
 
   registerDefaultHelpers(this);
+  registerDefaultDecorators(this);
 }
 
 HandlebarsEnvironment.prototype = {
   constructor: HandlebarsEnvironment,
 
   logger: logger,
-  log: log,
+  log: logger.log,
 
-  registerHelper: function(name, fn, inverse) {
+  registerHelper: function (name, fn) {
     if (toString.call(name) === objectType) {
-      if (inverse || fn) { throw new Exception('Arg not supported with multiple helpers'); }
-      Utils.extend(this.helpers, name);
+      if (fn) {
+        throw new Exception('Arg not supported with multiple helpers');
+      }
+      extend(this.helpers, name);
     } else {
-      if (inverse) { fn.not = inverse; }
       this.helpers[name] = fn;
     }
   },
-  unregisterHelper: function(name) {
+  unregisterHelper: function (name) {
     delete this.helpers[name];
   },
 
-  registerPartial: function(name, str) {
+  registerPartial: function (name, partial) {
     if (toString.call(name) === objectType) {
-      Utils.extend(this.partials,  name);
+      extend(this.partials, name);
     } else {
-      this.partials[name] = str;
+      if (typeof partial === 'undefined') {
+        throw new Exception(
+          `Attempting to register a partial called "${name}" as undefined`
+        );
+      }
+      this.partials[name] = partial;
     }
   },
-  unregisterPartial: function(name) {
+  unregisterPartial: function (name) {
     delete this.partials[name];
-  }
+  },
+
+  registerDecorator: function (name, fn) {
+    if (toString.call(name) === objectType) {
+      if (fn) {
+        throw new Exception('Arg not supported with multiple decorators');
+      }
+      extend(this.decorators, name);
+    } else {
+      this.decorators[name] = fn;
+    }
+  },
+  unregisterDecorator: function (name) {
+    delete this.decorators[name];
+  },
+  /**
+   * Reset the memory of illegal property accesses that have already been logged.
+   * @deprecated should only be used in handlebars test-cases
+   */
+  resetLoggedPropertyAccesses() {
+    resetLoggedProperties();
+  },
 };
 
-function registerDefaultHelpers(instance) {
-  instance.registerHelper('helperMissing', function(/* [args, ]options */) {
-    if(arguments.length === 1) {
-      // A missing field in a {{foo}} constuct.
-      return undefined;
-    } else {
-      // Someone is actually trying to call something, blow up.
-      throw new Exception("Missing helper: '" + arguments[arguments.length-1].name + "'");
-    }
-  });
+export let log = logger.log;
 
-  instance.registerHelper('blockHelperMissing', function(context, options) {
-    var inverse = options.inverse || function() {}, fn = options.fn;
-
-    if (isFunction(context)) { context = context.call(this); }
-
-    if(context === true) {
-      return fn(this);
-    } else if(context === false || context == null) {
-      return inverse(this);
-    } else if (isArray(context)) {
-      if(context.length > 0) {
-        if (options.ids) {
-          options.ids = [options.name];
-        }
-
-        return instance.helpers.each(context, options);
-      } else {
-        return inverse(this);
-      }
-    } else {
-      if (options.data && options.ids) {
-        var data = createFrame(options.data);
-        data.contextPath = Utils.appendContextPath(options.data.contextPath, options.name);
-        options = {data: data};
-      }
-
-      return fn(context, options);
-    }
-  });
-
-  instance.registerHelper('each', function(context, options) {
-    // Allow for {{#each}}
-    if (!options) {
-      options = context;
-      context = this;
-    }
-
-    var fn = options.fn, inverse = options.inverse;
-    var i = 0, ret = "", data;
-
-    var contextPath;
-    if (options.data && options.ids) {
-      contextPath = Utils.appendContextPath(options.data.contextPath, options.ids[0]) + '.';
-    }
-
-    if (isFunction(context)) { context = context.call(this); }
-
-    if (options.data) {
-      data = createFrame(options.data);
-    }
-
-    if(context && typeof context === 'object') {
-      if (isArray(context)) {
-        for(var j = context.length; i<j; i++) {
-          if (data) {
-            data.index = i;
-            data.first = (i === 0);
-            data.last  = (i === (context.length-1));
-
-            if (contextPath) {
-              data.contextPath = contextPath + i;
-            }
-          }
-          ret = ret + fn(context[i], { data: data });
-        }
-      } else {
-        for(var key in context) {
-          if(context.hasOwnProperty(key)) {
-            if(data) {
-              data.key = key;
-              data.index = i;
-              data.first = (i === 0);
-
-              if (contextPath) {
-                data.contextPath = contextPath + key;
-              }
-            }
-            ret = ret + fn(context[key], {data: data});
-            i++;
-          }
-        }
-      }
-    }
-
-    if(i === 0){
-      ret = inverse(this);
-    }
-
-    return ret;
-  });
-
-  instance.registerHelper('if', function(conditional, options) {
-    if (isFunction(conditional)) { conditional = conditional.call(this); }
-
-    // Default behavior is to render the positive path if the value is truthy and not empty.
-    // The `includeZero` option may be set to treat the condtional as purely not empty based on the
-    // behavior of isEmpty. Effectively this determines if 0 is handled by the positive path or negative.
-    if ((!options.hash.includeZero && !conditional) || Utils.isEmpty(conditional)) {
-      return options.inverse(this);
-    } else {
-      return options.fn(this);
-    }
-  });
-
-  instance.registerHelper('unless', function(conditional, options) {
-    return instance.helpers['if'].call(this, conditional, {fn: options.inverse, inverse: options.fn, hash: options.hash});
-  });
-
-  instance.registerHelper('with', function(context, options) {
-    if (isFunction(context)) { context = context.call(this); }
-
-    var fn = options.fn;
-
-    if (!Utils.isEmpty(context)) {
-      if (options.data && options.ids) {
-        var data = createFrame(options.data);
-        data.contextPath = Utils.appendContextPath(options.data.contextPath, options.ids[0]);
-        options = {data:data};
-      }
-
-      return fn(context, options);
-    }
-  });
-
-  instance.registerHelper('log', function(context, options) {
-    var level = options.data && options.data.level != null ? parseInt(options.data.level, 10) : 1;
-    instance.log(level, context);
-  });
-
-  instance.registerHelper('lookup', function(obj, field, options) {
-    return obj && obj[field];
-  });
-}
-
-export var logger = {
-  methodMap: { 0: 'debug', 1: 'info', 2: 'warn', 3: 'error' },
-
-  // State enum
-  DEBUG: 0,
-  INFO: 1,
-  WARN: 2,
-  ERROR: 3,
-  level: 3,
-
-  // can be overridden in the host environment
-  log: function(level, obj) {
-    if (logger.level <= level) {
-      var method = logger.methodMap[level];
-      if (typeof console !== 'undefined' && console[method]) {
-        console[method].call(console, obj);
-      }
-    }
-  }
-};
-
-export function log(level, obj) { logger.log(level, obj); }
-
-export var createFrame = function(object) {
-  var frame = Utils.extend({}, object);
-  frame._parent = object;
-  return frame;
-};
+export { createFrame, logger };

lib/handlebars/compiler/ast.js

@@ -1,246 +1,32 @@
-import Exception from "../exception";
-
-function LocationInfo(locInfo){
-  locInfo = locInfo || {};
-  this.firstLine   = locInfo.first_line;
-  this.firstColumn = locInfo.first_column;
-  this.lastColumn  = locInfo.last_column;
-  this.lastLine    = locInfo.last_line;
-}
-
-var AST = {
-  ProgramNode: function(statements, inverseStrip, inverse, locInfo) {
-    var inverseLocationInfo, firstInverseNode;
-    if (arguments.length === 3) {
-      locInfo = inverse;
-      inverse = null;
-    } else if (arguments.length === 2) {
-      locInfo = inverseStrip;
-      inverseStrip = null;
-    }
-
-    LocationInfo.call(this, locInfo);
-    this.type = "program";
-    this.statements = statements;
-    this.strip = {};
-
-    if(inverse) {
-      firstInverseNode = inverse[0];
-      if (firstInverseNode) {
-        inverseLocationInfo = {
-          first_line: firstInverseNode.firstLine,
-          last_line: firstInverseNode.lastLine,
-          last_column: firstInverseNode.lastColumn,
-          first_column: firstInverseNode.firstColumn
-        };
-        this.inverse = new AST.ProgramNode(inverse, inverseStrip, inverseLocationInfo);
-      } else {
-        this.inverse = new AST.ProgramNode(inverse, inverseStrip);
-      }
-      this.strip.right = inverseStrip.left;
-    } else if (inverseStrip) {
-      this.strip.left = inverseStrip.right;
-    }
-  },
-
-  MustacheNode: function(rawParams, hash, open, strip, locInfo) {
-    LocationInfo.call(this, locInfo);
-    this.type = "mustache";
-    this.strip = strip;
-
-    // Open may be a string parsed from the parser or a passed boolean flag
-    if (open != null && open.charAt) {
-      // Must use charAt to support IE pre-10
-      var escapeFlag = open.charAt(3) || open.charAt(2);
-      this.escaped = escapeFlag !== '{' && escapeFlag !== '&';
-    } else {
-      this.escaped = !!open;
-    }
-
-    if (rawParams instanceof AST.SexprNode) {
-      this.sexpr = rawParams;
-    } else {
-      // Support old AST API
-      this.sexpr = new AST.SexprNode(rawParams, hash);
-    }
-
-    this.sexpr.isRoot = true;
-
-    // Support old AST API that stored this info in MustacheNode
-    this.id = this.sexpr.id;
-    this.params = this.sexpr.params;
-    this.hash = this.sexpr.hash;
-    this.eligibleHelper = this.sexpr.eligibleHelper;
-    this.isHelper = this.sexpr.isHelper;
-  },
-
-  SexprNode: function(rawParams, hash, locInfo) {
-    LocationInfo.call(this, locInfo);
-
-    this.type = "sexpr";
-    this.hash = hash;
-
-    var id = this.id = rawParams[0];
-    var params = this.params = rawParams.slice(1);
-
+let AST = {
+  // Public API used to evaluate derived attributes regarding AST nodes
+  helpers: {
     // a mustache is definitely a helper if:
     // * it is an eligible helper, and
     // * it has at least one parameter or hash segment
-    this.isHelper = !!(params.length || hash);
+    helperExpression: function (node) {
+      return (
+        node.type === 'SubExpression' ||
+        ((node.type === 'MustacheStatement' ||
+          node.type === 'BlockStatement') &&
+          !!((node.params && node.params.length) || node.hash))
+      );
+    },
 
-    // a mustache is an eligible helper if:
-    // * its id is simple (a single part, not `this` or `..`)
-    this.eligibleHelper = this.isHelper || id.isSimple;
-
-    // if a mustache is an eligible helper but not a definite
-    // helper, it is ambiguous, and will be resolved in a later
-    // pass or at runtime.
-  },
-
-  PartialNode: function(partialName, context, hash, strip, locInfo) {
-    LocationInfo.call(this, locInfo);
-    this.type         = "partial";
-    this.partialName  = partialName;
-    this.context      = context;
-    this.hash = hash;
-    this.strip = strip;
-  },
-
-  BlockNode: function(mustache, program, inverse, close, locInfo) {
-    LocationInfo.call(this, locInfo);
-
-    if(mustache.sexpr.id.original !== close.path.original) {
-      throw new Exception(mustache.sexpr.id.original + " doesn't match " + close.path.original, this);
-    }
-
-    this.type = 'block';
-    this.mustache = mustache;
-    this.program  = program;
-    this.inverse  = inverse;
-
-    this.strip = {
-      left: mustache.strip.left,
-      right: close.strip.right
-    };
-
-    (program || inverse).strip.left = mustache.strip.right;
-    (inverse || program).strip.right = close.strip.left;
-
-    if (inverse && !program) {
-      this.isInverse = true;
-    }
-  },
-
-  RawBlockNode: function(mustache, content, close, locInfo) {
-    LocationInfo.call(this, locInfo);
-
-    if (mustache.sexpr.id.original !== close) {
-      throw new Exception(mustache.sexpr.id.original + " doesn't match " + close, this);
-    }
-
-    content = new AST.ContentNode(content, locInfo);
-
-    this.type = 'block';
-    this.mustache = mustache;
-    this.program = new AST.ProgramNode([content], locInfo);
-  },
-
-  ContentNode: function(string, locInfo) {
-    LocationInfo.call(this, locInfo);
-    this.type = "content";
-    this.string = string;
-  },
-
-  HashNode: function(pairs, locInfo) {
-    LocationInfo.call(this, locInfo);
-    this.type = "hash";
-    this.pairs = pairs;
-  },
-
-  IdNode: function(parts, locInfo) {
-    LocationInfo.call(this, locInfo);
-    this.type = "ID";
-
-    var original = "",
-        dig = [],
-        depth = 0,
-        depthString = '';
-
-    for(var i=0,l=parts.length; i<l; i++) {
-      var part = parts[i].part;
-      original += (parts[i].separator || '') + part;
-
-      if (part === ".." || part === "." || part === "this") {
-        if (dig.length > 0) {
-          throw new Exception("Invalid path: " + original, this);
-        } else if (part === "..") {
-          depth++;
-          depthString += '../';
-        } else {
-          this.isScoped = true;
-        }
-      } else {
-        dig.push(part);
-      }
-    }
-
-    this.original = original;
-    this.parts    = dig;
-    this.string   = dig.join('.');
-    this.depth    = depth;
-    this.idName   = depthString + this.string;
+    scopedId: function (path) {
+      return /^\.|this\b/.test(path.original);
+    },
 
     // an ID is simple if it only has one part, and that part is not
     // `..` or `this`.
-    this.isSimple = parts.length === 1 && !this.isScoped && depth === 0;
-
-    this.stringModeValue = this.string;
+    simpleId: function (path) {
+      return (
+        path.parts.length === 1 && !AST.helpers.scopedId(path) && !path.depth
+      );
+    },
   },
-
-  PartialNameNode: function(name, locInfo) {
-    LocationInfo.call(this, locInfo);
-    this.type = "PARTIAL_NAME";
-    this.name = name.original;
-  },
-
-  DataNode: function(id, locInfo) {
-    LocationInfo.call(this, locInfo);
-    this.type = "DATA";
-    this.id = id;
-    this.stringModeValue = id.stringModeValue;
-    this.idName = '@' + id.stringModeValue;
-  },
-
-  StringNode: function(string, locInfo) {
-    LocationInfo.call(this, locInfo);
-    this.type = "STRING";
-    this.original =
-      this.string =
-      this.stringModeValue = string;
-  },
-
-  NumberNode: function(number, locInfo) {
-    LocationInfo.call(this, locInfo);
-    this.type = "NUMBER";
-    this.original =
-      this.number = number;
-    this.stringModeValue = Number(number);
-  },
-
-  BooleanNode: function(bool, locInfo) {
-    LocationInfo.call(this, locInfo);
-    this.type = "BOOLEAN";
-    this.bool = bool;
-    this.stringModeValue = bool === "true";
-  },
-
-  CommentNode: function(comment, locInfo) {
-    LocationInfo.call(this, locInfo);
-    this.type = "comment";
-    this.comment = comment;
-  }
 };
 
 // Must be exported as an object rather than the root of the module as the jison lexer
-// most modify the object to operate properly.
+// must modify the object to operate properly.
 export default AST;

lib/handlebars/compiler/base.js

@@ -1,12 +0,0 @@
-import parser from "./parser";
-import AST from "./ast";
-
-export { parser };
-
-export function parse(input) {
-  // Just return if an already-compile AST was passed in.
-  if(input.constructor === AST.ProgramNode) { return input; }
-
-  parser.yy = AST;
-  return parser.parse(input);
-}

lib/handlebars/compiler/code-gen.js

@@ -0,0 +1,177 @@
+/* global define */
+import { isArray } from '../utils';
+
+let SourceNode;
+
+try {
+  /* v8 ignore next */
+  if (typeof define !== 'function' || !define.amd) {
+    // We don't support this in AMD environments. For these environments, we assume that
+    // they are running on the browser and thus have no need for the source-map library.
+    // The variable indirection prevents bundlers from statically resolving and bundling
+    // source-map (which requires Node-built-ins). The stub SourceNode below handles
+    // browser/bundled usage. Bundlers may emit a "Critical dependency" warning — this
+    // is expected and harmless.
+    let mod = 'source-map';
+    let SourceMap = require(mod);
+    SourceNode = SourceMap.SourceNode;
+  }
+  // oxlint-disable-next-line no-unused-vars -- Babel 5 requires named catch param
+} catch (err) {
+  /* NOP */
+}
+
+/* v8 ignore next -- tested but not covered due to dist build */
+if (!SourceNode) {
+  SourceNode = function (line, column, srcFile, chunks) {
+    this.src = '';
+    if (chunks) {
+      this.add(chunks);
+    }
+  };
+  /* v8 ignore next */
+  SourceNode.prototype = {
+    add: function (chunks) {
+      if (isArray(chunks)) {
+        chunks = chunks.join('');
+      }
+      this.src += chunks;
+    },
+    prepend: function (chunks) {
+      if (isArray(chunks)) {
+        chunks = chunks.join('');
+      }
+      this.src = chunks + this.src;
+    },
+    toStringWithSourceMap: function () {
+      return { code: this.toString() };
+    },
+    toString: function () {
+      return this.src;
+    },
+  };
+}
+
+function castChunk(chunk, codeGen, loc) {
+  if (isArray(chunk)) {
+    let ret = [];
+
+    for (let i = 0, len = chunk.length; i < len; i++) {
+      ret.push(codeGen.wrap(chunk[i], loc));
+    }
+    return ret;
+  } else if (typeof chunk === 'boolean' || typeof chunk === 'number') {
+    // Handle primitives that the SourceNode will throw up on
+    return chunk + '';
+  }
+  return chunk;
+}
+
+function CodeGen(srcFile) {
+  this.srcFile = srcFile;
+  this.source = [];
+}
+
+CodeGen.prototype = {
+  isEmpty() {
+    return !this.source.length;
+  },
+  prepend: function (source, loc) {
+    this.source.unshift(this.wrap(source, loc));
+  },
+  push: function (source, loc) {
+    this.source.push(this.wrap(source, loc));
+  },
+
+  merge: function () {
+    let source = this.empty();
+    this.each(function (line) {
+      source.add(['  ', line, '\n']);
+    });
+    return source;
+  },
+
+  each: function (iter) {
+    for (let i = 0, len = this.source.length; i < len; i++) {
+      iter(this.source[i]);
+    }
+  },
+
+  empty: function () {
+    let loc = this.currentLocation || { start: {} };
+    return new SourceNode(loc.start.line, loc.start.column, this.srcFile);
+  },
+  wrap: function (chunk, loc = this.currentLocation || { start: {} }) {
+    if (chunk instanceof SourceNode) {
+      return chunk;
+    }
+
+    chunk = castChunk(chunk, this, loc);
+
+    return new SourceNode(
+      loc.start.line,
+      loc.start.column,
+      this.srcFile,
+      chunk
+    );
+  },
+
+  functionCall: function (fn, type, params) {
+    params = this.generateList(params);
+    return this.wrap([fn, type ? '.' + type + '(' : '(', params, ')']);
+  },
+
+  quotedString: function (str) {
+    return (
+      '"' +
+      (str + '')
+        .replace(/\\/g, '\\\\')
+        .replace(/"/g, '\\"')
+        .replace(/\n/g, '\\n')
+        .replace(/\r/g, '\\r')
+        .replace(/\u2028/g, '\\u2028') // Per Ecma-262 7.3 + 7.8.4
+        .replace(/\u2029/g, '\\u2029') +
+      '"'
+    );
+  },
+
+  objectLiteral: function (obj) {
+    let pairs = [];
+
+    Object.keys(obj).forEach((key) => {
+      let value = castChunk(obj[key], this);
+      if (value !== 'undefined') {
+        pairs.push([this.quotedString(key), ':', value]);
+      }
+    });
+
+    let ret = this.generateList(pairs);
+    ret.prepend('{');
+    ret.add('}');
+    return ret;
+  },
+
+  generateList: function (entries) {
+    let ret = this.empty();
+
+    for (let i = 0, len = entries.length; i < len; i++) {
+      if (i) {
+        ret.add(',');
+      }
+
+      ret.add(castChunk(entries[i], this));
+    }
+
+    return ret;
+  },
+
+  generateArray: function (entries) {
+    let ret = this.generateList(entries);
+    ret.prepend('[');
+    ret.add(']');
+
+    return ret;
+  },
+};
+
+export default CodeGen;

lib/handlebars/compiler/compiler.js

@@ -1,4 +1,8 @@
-import Exception from "../exception";
+import { Exception } from '@handlebars/parser';
+import { isArray, indexOf, extend } from '../utils';
+import AST from './ast';
+
+const slice = [].slice;
 
 export function Compiler() {}
 
@@ -10,54 +14,27 @@ export function Compiler() {}
 Compiler.prototype = {
   compiler: Compiler,
 
-  disassemble: function() {
-    var opcodes = this.opcodes, opcode, out = [], params, param;
-
-    for (var i=0, l=opcodes.length; i<l; i++) {
-      opcode = opcodes[i];
-
-      if (opcode.opcode === 'DECLARE') {
-        out.push("DECLARE " + opcode.name + "=" + opcode.value);
-      } else {
-        params = [];
-        for (var j=0; j<opcode.args.length; j++) {
-          param = opcode.args[j];
-          if (typeof param === "string") {
-            param = "\"" + param.replace("\n", "\\n") + "\"";
-          }
-          params.push(param);
-        }
-        out.push(opcode.opcode + " " + params.join(" "));
-      }
-    }
-
-    return out.join("\n");
-  },
-
-  equals: function(other) {
-    var len = this.opcodes.length;
+  equals: function (other) {
+    let len = this.opcodes.length;
     if (other.opcodes.length !== len) {
       return false;
     }
 
-    for (var i = 0; i < len; i++) {
-      var opcode = this.opcodes[i],
-          otherOpcode = other.opcodes[i];
-      if (opcode.opcode !== otherOpcode.opcode || opcode.args.length !== otherOpcode.args.length) {
+    for (let i = 0; i < len; i++) {
+      let opcode = this.opcodes[i],
+        otherOpcode = other.opcodes[i];
+      if (
+        opcode.opcode !== otherOpcode.opcode ||
+        !argEquals(opcode.args, otherOpcode.args)
+      ) {
         return false;
       }
-      for (var j = 0; j < opcode.args.length; j++) {
-        if (opcode.args[j] !== otherOpcode.args[j]) {
-          return false;
-        }
-      }
     }
 
+    // We know that length is the same between the two arrays because they are directly tied
+    // to the opcode behavior above.
     len = this.children.length;
-    if (other.children.length !== len) {
-      return false;
-    }
-    for (i = 0; i < len; i++) {
+    for (let i = 0; i < len; i++) {
       if (!this.children[i].equals(other.children[i])) {
         return false;
       }
@@ -68,113 +45,98 @@ Compiler.prototype = {
 
   guid: 0,
 
-  compile: function(program, options) {
+  compile: function (program, options) {
+    this.sourceNode = [];
     this.opcodes = [];
     this.children = [];
-    this.depths = {list: []};
     this.options = options;
-    this.stringParams = options.stringParams;
-    this.trackIds = options.trackIds;
 
-    // These changes will propagate to the other compiler components
-    var knownHelpers = this.options.knownHelpers;
-    this.options.knownHelpers = {
-      'helperMissing': true,
-      'blockHelperMissing': true,
-      'each': true,
-      'if': true,
-      'unless': true,
-      'with': true,
-      'log': true,
-      'lookup': true
-    };
-    if (knownHelpers) {
-      for (var name in knownHelpers) {
-        this.options.knownHelpers[name] = knownHelpers[name];
-      }
-    }
+    options.blockParams = options.blockParams || [];
+
+    options.knownHelpers = extend(
+      Object.create(null),
+      {
+        helperMissing: true,
+        blockHelperMissing: true,
+        each: true,
+        if: true,
+        unless: true,
+        with: true,
+        log: true,
+        lookup: true,
+      },
+      options.knownHelpers
+    );
 
     return this.accept(program);
   },
 
-  accept: function(node) {
-    var strip = node.strip || {},
-        ret;
-    if (strip.left) {
-      this.opcode('strip');
-    }
-
-    ret = this[node.type](node);
-
-    if (strip.right) {
-      this.opcode('strip');
-    }
-
-    return ret;
-  },
-
-  program: function(program) {
-    var statements = program.statements;
-
-    for(var i=0, l=statements.length; i<l; i++) {
-      this.accept(statements[i]);
-    }
-    this.isSimple = l === 1;
-
-    this.depths.list = this.depths.list.sort(function(a, b) {
-      return a - b;
-    });
-
-    return this;
-  },
-
-  compileProgram: function(program) {
-    var result = new this.compiler().compile(program, this.options);
-    var guid = this.guid++, depth;
+  compileProgram: function (program) {
+    let childCompiler = new this.compiler(),
+      result = childCompiler.compile(program, this.options),
+      guid = this.guid++;
 
     this.usePartial = this.usePartial || result.usePartial;
 
     this.children[guid] = result;
-
-    for(var i=0, l=result.depths.list.length; i<l; i++) {
-      depth = result.depths.list[i];
-
-      if(depth < 2) { continue; }
-      else { this.addDepth(depth - 1); }
-    }
+    this.useDepths = this.useDepths || result.useDepths;
 
     return guid;
   },
 
-  block: function(block) {
-    var mustache = block.mustache,
-        program = block.program,
-        inverse = block.inverse;
-
-    if (program) {
-      program = this.compileProgram(program);
+  accept: function (node) {
+    /* v8 ignore next -- Sanity code */
+    if (!this[node.type]) {
+      throw new Exception('Unknown type: ' + node.type, node);
     }
 
-    if (inverse) {
-      inverse = this.compileProgram(inverse);
+    this.sourceNode.unshift(node);
+    let ret = this[node.type](node);
+    this.sourceNode.shift();
+    return ret;
+  },
+
+  Program: function (program) {
+    this.options.blockParams.unshift(program.blockParams);
+
+    let body = program.body,
+      bodyLength = body.length;
+    for (let i = 0; i < bodyLength; i++) {
+      this.accept(body[i]);
     }
 
-    var sexpr = mustache.sexpr;
-    var type = this.classifySexpr(sexpr);
+    this.options.blockParams.shift();
 
-    if (type === "helper") {
-      this.helperSexpr(sexpr, program, inverse);
-    } else if (type === "simple") {
-      this.simpleSexpr(sexpr);
+    this.isSimple = bodyLength === 1;
+    this.blockParams = program.blockParams ? program.blockParams.length : 0;
+
+    return this;
+  },
+
+  BlockStatement: function (block) {
+    transformLiteralToPath(block);
+
+    let program = block.program,
+      inverse = block.inverse;
+
+    program = program && this.compileProgram(program);
+    inverse = inverse && this.compileProgram(inverse);
+
+    let type = this.classifySexpr(block);
+
+    if (type === 'helper') {
+      this.helperSexpr(block, program, inverse);
+    } else if (type === 'simple') {
+      this.simpleSexpr(block);
 
       // now that the simple mustache is resolved, we need to
       // evaluate it by executing `blockHelperMissing`
       this.opcode('pushProgram', program);
       this.opcode('pushProgram', inverse);
       this.opcode('emptyHash');
-      this.opcode('blockValue', sexpr.id.original);
+      this.opcode('blockValue', block.path.original);
     } else {
-      this.ambiguousSexpr(sexpr, program, inverse);
+      this.ambiguousSexpr(block, program, inverse);
 
       // now that the simple mustache is resolved, we need to
       // evaluate it by executing `blockHelperMissing`
@@ -187,178 +149,239 @@ Compiler.prototype = {
     this.opcode('append');
   },
 
-  hash: function(hash) {
-    var pairs = hash.pairs, i, l;
+  DecoratorBlock(decorator) {
+    let program = decorator.program && this.compileProgram(decorator.program);
+    let params = this.setupFullMustacheParams(decorator, program, undefined),
+      path = decorator.path;
 
-    this.opcode('pushHash');
-
-    for(i=0, l=pairs.length; i<l; i++) {
-      this.pushParam(pairs[i][1]);
-    }
-    while(i--) {
-      this.opcode('assignToHash', pairs[i][0]);
-    }
-    this.opcode('popHash');
+    this.useDecorators = true;
+    this.opcode('registerDecorator', params.length, path.original);
   },
 
-  partial: function(partial) {
-    var partialName = partial.partialName;
+  PartialStatement: function (partial) {
     this.usePartial = true;
 
-    if (partial.hash) {
-      this.accept(partial.hash);
-    } else {
-      this.opcode('push', 'undefined');
+    let program = partial.program;
+    if (program) {
+      program = this.compileProgram(partial.program);
     }
 
-    if (partial.context) {
-      this.accept(partial.context);
-    } else {
-      this.opcode('push', 'depth0');
+    let params = partial.params;
+    if (params.length > 1) {
+      throw new Exception(
+        'Unsupported number of partial arguments: ' + params.length,
+        partial
+      );
+    } else if (!params.length) {
+      if (this.options.explicitPartialContext) {
+        this.opcode('pushLiteral', 'undefined');
+      } else {
+        params.push({ type: 'PathExpression', parts: [], depth: 0 });
+      }
     }
 
-    this.opcode('invokePartial', partialName.name);
+    let partialName = partial.name.original,
+      isDynamic = partial.name.type === 'SubExpression';
+    if (isDynamic) {
+      this.accept(partial.name);
+    }
+
+    this.setupFullMustacheParams(partial, program, undefined, true);
+
+    let indent = partial.indent || '';
+    if (this.options.preventIndent && indent) {
+      this.opcode('appendContent', indent);
+      indent = '';
+    }
+
+    this.opcode('invokePartial', isDynamic, partialName, indent);
     this.opcode('append');
   },
-
-  content: function(content) {
-    this.opcode('appendContent', content.string);
+  PartialBlockStatement: function (partialBlock) {
+    this.PartialStatement(partialBlock);
   },
 
-  mustache: function(mustache) {
-    this.sexpr(mustache.sexpr);
+  MustacheStatement: function (mustache) {
+    this.SubExpression(mustache);
 
-    if(mustache.escaped && !this.options.noEscape) {
+    if (mustache.escaped && !this.options.noEscape) {
       this.opcode('appendEscaped');
     } else {
       this.opcode('append');
     }
   },
-
-  ambiguousSexpr: function(sexpr, program, inverse) {
-    var id = sexpr.id,
-        name = id.parts[0],
-        isBlock = program != null || inverse != null;
-
-    this.opcode('getContext', id.depth);
-
-    this.opcode('pushProgram', program);
-    this.opcode('pushProgram', inverse);
-
-    this.opcode('invokeAmbiguous', name, isBlock);
+  Decorator(decorator) {
+    this.DecoratorBlock(decorator);
   },
 
-  simpleSexpr: function(sexpr) {
-    var id = sexpr.id;
-
-    if (id.type === 'DATA') {
-      this.DATA(id);
-    } else if (id.parts.length) {
-      this.ID(id);
-    } else {
-      // Simplified ID for `this`
-      this.addDepth(id.depth);
-      this.opcode('getContext', id.depth);
-      this.opcode('pushContext');
-    }
-
-    this.opcode('resolvePossibleLambda');
-  },
-
-  helperSexpr: function(sexpr, program, inverse) {
-    var params = this.setupFullMustacheParams(sexpr, program, inverse),
-        id = sexpr.id,
-        name = id.parts[0];
-
-    if (this.options.knownHelpers[name]) {
-      this.opcode('invokeKnownHelper', params.length, name);
-    } else if (this.options.knownHelpersOnly) {
-      throw new Exception("You specified knownHelpersOnly, but used the unknown helper " + name, sexpr);
-    } else {
-      this.ID(id);
-      this.opcode('invokeHelper', params.length, id.original, sexpr.isRoot);
+  ContentStatement: function (content) {
+    if (content.value) {
+      this.opcode('appendContent', content.value);
     }
   },
 
-  sexpr: function(sexpr) {
-    var type = this.classifySexpr(sexpr);
+  CommentStatement: function () {},
 
-    if (type === "simple") {
+  SubExpression: function (sexpr) {
+    transformLiteralToPath(sexpr);
+    let type = this.classifySexpr(sexpr);
+
+    if (type === 'simple') {
       this.simpleSexpr(sexpr);
-    } else if (type === "helper") {
+    } else if (type === 'helper') {
       this.helperSexpr(sexpr);
     } else {
       this.ambiguousSexpr(sexpr);
     }
   },
+  ambiguousSexpr: function (sexpr, program, inverse) {
+    let path = sexpr.path,
+      name = path.parts[0],
+      isBlock = program != null || inverse != null;
 
-  ID: function(id) {
-    this.addDepth(id.depth);
-    this.opcode('getContext', id.depth);
+    this.opcode('getContext', path.depth);
 
-    var name = id.parts[0];
-    if (!name) {
-      this.opcode('pushContext');
+    this.opcode('pushProgram', program);
+    this.opcode('pushProgram', inverse);
+
+    path.strict = true;
+    this.accept(path);
+
+    this.opcode('invokeAmbiguous', name, isBlock);
+  },
+
+  simpleSexpr: function (sexpr) {
+    let path = sexpr.path;
+    path.strict = true;
+    this.accept(path);
+    this.opcode('resolvePossibleLambda');
+  },
+
+  helperSexpr: function (sexpr, program, inverse) {
+    let params = this.setupFullMustacheParams(sexpr, program, inverse),
+      path = sexpr.path,
+      name = path.parts[0];
+
+    if (this.options.knownHelpers[name]) {
+      this.opcode('invokeKnownHelper', params.length, name);
+    } else if (this.options.knownHelpersOnly) {
+      throw new Exception(
+        'You specified knownHelpersOnly, but used the unknown helper ' + name,
+        sexpr
+      );
     } else {
-      this.opcode('lookupOnContext', id.parts[0]);
-    }
+      path.strict = true;
+      path.falsy = true;
 
-    for(var i=1, l=id.parts.length; i<l; i++) {
-      this.opcode('lookup', id.parts[i]);
+      this.accept(path);
+      this.opcode(
+        'invokeHelper',
+        params.length,
+        path.original,
+        AST.helpers.simpleId(path)
+      );
     }
   },
 
-  DATA: function(data) {
-    this.options.data = true;
-    this.opcode('lookupData', data.id.depth);
-    var parts = data.id.parts;
-    for(var i=0, l=parts.length; i<l; i++) {
-      this.opcode('lookup', parts[i]);
+  PathExpression: function (path) {
+    this.addDepth(path.depth);
+    this.opcode('getContext', path.depth);
+
+    let name = path.parts[0],
+      scoped = AST.helpers.scopedId(path),
+      blockParamId = !path.depth && !scoped && this.blockParamIndex(name);
+
+    if (blockParamId) {
+      this.opcode('lookupBlockParam', blockParamId, path.parts);
+    } else if (!name) {
+      // Context reference, i.e. `{{foo .}}` or `{{foo ..}}`
+      this.opcode('pushContext');
+    } else if (path.data) {
+      this.options.data = true;
+      this.opcode('lookupData', path.depth, path.parts, path.strict);
+    } else {
+      this.opcode(
+        'lookupOnContext',
+        path.parts,
+        path.falsy,
+        path.strict,
+        scoped
+      );
     }
   },
 
-  STRING: function(string) {
-    this.opcode('pushString', string.string);
+  StringLiteral: function (string) {
+    this.opcode('pushString', string.value);
   },
 
-  NUMBER: function(number) {
-    this.opcode('pushLiteral', number.number);
+  NumberLiteral: function (number) {
+    this.opcode('pushLiteral', number.value);
   },
 
-  BOOLEAN: function(bool) {
-    this.opcode('pushLiteral', bool.bool);
+  BooleanLiteral: function (bool) {
+    this.opcode('pushLiteral', bool.value);
   },
 
-  comment: function() {},
+  UndefinedLiteral: function () {
+    this.opcode('pushLiteral', 'undefined');
+  },
+
+  NullLiteral: function () {
+    this.opcode('pushLiteral', 'null');
+  },
+
+  Hash: function (hash) {
+    let pairs = hash.pairs,
+      i = 0,
+      l = pairs.length;
+
+    this.opcode('pushHash');
+
+    for (; i < l; i++) {
+      this.pushParam(pairs[i].value);
+    }
+    while (i--) {
+      this.opcode('assignToHash', pairs[i].key);
+    }
+    this.opcode('popHash');
+  },
 
   // HELPERS
-  opcode: function(name) {
-    this.opcodes.push({ opcode: name, args: [].slice.call(arguments, 1) });
+  opcode: function (name) {
+    this.opcodes.push({
+      opcode: name,
+      args: slice.call(arguments, 1),
+      loc: this.sourceNode[0].loc,
+    });
   },
 
-  declare: function(name, value) {
-    this.opcodes.push({ opcode: 'DECLARE', name: name, value: value });
-  },
-
-  addDepth: function(depth) {
-    if(depth === 0) { return; }
-
-    if(!this.depths[depth]) {
-      this.depths[depth] = true;
-      this.depths.list.push(depth);
+  addDepth: function (depth) {
+    if (!depth) {
+      return;
     }
+
+    this.useDepths = true;
   },
 
-  classifySexpr: function(sexpr) {
-    var isHelper   = sexpr.isHelper;
-    var isEligible = sexpr.eligibleHelper;
-    var options    = this.options;
+  classifySexpr: function (sexpr) {
+    let isSimple = AST.helpers.simpleId(sexpr.path);
+
+    let isBlockParam = isSimple && !!this.blockParamIndex(sexpr.path.parts[0]);
+
+    // a mustache is an eligible helper if:
+    // * its id is simple (a single part, not `this` or `..`)
+    let isHelper = !isBlockParam && AST.helpers.helperExpression(sexpr);
+
+    // if a mustache is an eligible helper but not a definite
+    // helper, it is ambiguous, and will be resolved in a later
+    // pass or at runtime.
+    let isEligible = !isBlockParam && (isHelper || isSimple);
 
     // if ambiguous, we can possibly resolve the ambiguity now
     // An eligible helper is one that does not have a complex path, i.e. `this.foo`, `../foo` etc.
     if (isEligible && !isHelper) {
-      var name = sexpr.id.parts[0];
-
+      let name = sexpr.path.parts[0],
+        options = this.options;
       if (options.knownHelpers[name]) {
         isHelper = true;
       } else if (options.knownHelpersOnly) {
@@ -366,108 +389,146 @@ Compiler.prototype = {
       }
     }
 
-    if (isHelper) { return "helper"; }
-    else if (isEligible) { return "ambiguous"; }
-    else { return "simple"; }
+    if (isHelper) {
+      return 'helper';
+    } else if (isEligible) {
+      return 'ambiguous';
+    } else {
+      return 'simple';
+    }
   },
 
-  pushParams: function(params) {
-    for(var i=0, l=params.length; i<l; i++) {
+  pushParams: function (params) {
+    for (let i = 0, l = params.length; i < l; i++) {
       this.pushParam(params[i]);
     }
   },
 
-  pushParam: function(val) {
-    if (this.stringParams) {
-      if(val.depth) {
-        this.addDepth(val.depth);
-      }
-      this.opcode('getContext', val.depth || 0);
-      this.opcode('pushStringParam', val.stringModeValue, val.type);
-
-      if (val.type === 'sexpr') {
-        // Subexpressions get evaluated and passed in
-        // in string params mode.
-        this.sexpr(val);
-      }
-    } else {
-      if (this.trackIds) {
-        this.opcode('pushId', val.type, val.idName || val.stringModeValue);
-      }
-      this.accept(val);
-    }
+  pushParam: function (val) {
+    this.accept(val);
   },
 
-  setupFullMustacheParams: function(sexpr, program, inverse) {
-    var params = sexpr.params;
+  setupFullMustacheParams: function (sexpr, program, inverse, omitEmpty) {
+    let params = sexpr.params;
     this.pushParams(params);
 
     this.opcode('pushProgram', program);
     this.opcode('pushProgram', inverse);
 
     if (sexpr.hash) {
-      this.hash(sexpr.hash);
+      this.accept(sexpr.hash);
     } else {
-      this.opcode('emptyHash');
+      this.opcode('emptyHash', omitEmpty);
     }
 
     return params;
-  }
+  },
+
+  blockParamIndex: function (name) {
+    for (
+      let depth = 0, len = this.options.blockParams.length;
+      depth < len;
+      depth++
+    ) {
+      let blockParams = this.options.blockParams[depth],
+        param = blockParams && indexOf(blockParams, name);
+      if (blockParams && param >= 0) {
+        return [depth, param];
+      }
+    }
+  },
 };
 
-export function precompile(input, options, env) {
-  if (input == null || (typeof input !== 'string' && input.constructor !== env.AST.ProgramNode)) {
-    throw new Exception("You must pass a string or Handlebars AST to Handlebars.precompile. You passed " + input);
-  }
+export function precompile(input, options = {}, env) {
+  validateInput(input, options);
 
-  options = options || {};
-  if (!('data' in options)) {
-    options.data = true;
-  }
-
-  var ast = env.parse(input);
-  var environment = new env.Compiler().compile(ast, options);
+  let environment = compileEnvironment(input, options, env);
   return new env.JavaScriptCompiler().compile(environment, options);
 }
 
-export function compile(input, options, env) {
-  if (input == null || (typeof input !== 'string' && input.constructor !== env.AST.ProgramNode)) {
-    throw new Exception("You must pass a string or Handlebars AST to Handlebars.compile. You passed " + input);
-  }
+export function compile(input, options = {}, env) {
+  options = extend({}, options);
 
-  options = options || {};
+  validateInput(input, options);
 
-  if (!('data' in options)) {
-    options.data = true;
-  }
-
-  var compiled;
+  let compiled;
 
   function compileInput() {
-    var ast = env.parse(input);
-    var environment = new env.Compiler().compile(ast, options);
-    var templateSpec = new env.JavaScriptCompiler().compile(environment, options, undefined, true);
+    let environment = compileEnvironment(input, options, env),
+      templateSpec = new env.JavaScriptCompiler().compile(
+        environment,
+        options,
+        undefined,
+        true
+      );
     return env.template(templateSpec);
   }
 
   // Template is only compiled on first use and cached after that point.
-  var ret = function(context, options) {
+  return function (context, execOptions) {
     if (!compiled) {
       compiled = compileInput();
     }
-    return compiled.call(this, context, options);
+    return compiled.call(this, context, execOptions);
   };
-  ret._setup = function(options) {
-    if (!compiled) {
-      compiled = compileInput();
-    }
-    return compiled._setup(options);
-  };
-  ret._child = function(i) {
-    if (!compiled) {
-      compiled = compileInput();
-    }
-    return compiled._child(i);
-  };
-  return ret;
+}
+
+function validateInput(input, options) {
+  if (
+    input == null ||
+    (typeof input !== 'string' && input.type !== 'Program')
+  ) {
+    throw new Exception(
+      'You must pass a string or Handlebars AST to Handlebars.compile. You passed ' +
+        input
+    );
+  }
+
+  if (options.trackIds || options.stringParams) {
+    throw new Exception(
+      'TrackIds and stringParams are no longer supported. See Github #1145'
+    );
+  }
+
+  if (!('data' in options)) {
+    options.data = true;
+  }
+  if (options.compat) {
+    options.useDepths = true;
+  }
+}
+function compileEnvironment(input, options, env) {
+  let ast = env.parse(input, options);
+  return new env.Compiler().compile(ast, options);
+}
+
+function argEquals(a, b) {
+  if (a === b) {
+    return true;
+  }
+
+  if (isArray(a) && isArray(b) && a.length === b.length) {
+    for (let i = 0; i < a.length; i++) {
+      if (!argEquals(a[i], b[i])) {
+        return false;
+      }
+    }
+    return true;
+  }
+}
+
+function transformLiteralToPath(sexpr) {
+  if (!sexpr.path.parts) {
+    let literal = sexpr.path;
+    // Casting to string here to make false and 0 literal values play nicely with the rest
+    // of the system.
+    sexpr.path = {
+      type: 'PathExpression',
+      data: false,
+      depth: 0,
+      parts: [literal.original + ''],
+      original: literal.original + '',
+      loc: literal.loc,
+    };
+  }
 }

lib/handlebars/compiler/printer.js

@@ -1,143 +0,0 @@
-import Visitor from "./visitor";
-
-export function print(ast) {
-  return new PrintVisitor().accept(ast);
-}
-
-export function PrintVisitor() {
-  this.padding = 0;
-}
-
-PrintVisitor.prototype = new Visitor();
-
-PrintVisitor.prototype.pad = function(string, newline) {
-  var out = "";
-
-  for(var i=0,l=this.padding; i<l; i++) {
-    out = out + "  ";
-  }
-
-  out = out + string;
-
-  if(newline !== false) { out = out + "\n"; }
-  return out;
-};
-
-PrintVisitor.prototype.program = function(program) {
-  var out = "",
-      statements = program.statements,
-      i, l;
-
-  for(i=0, l=statements.length; i<l; i++) {
-    out = out + this.accept(statements[i]);
-  }
-
-  this.padding--;
-
-  return out;
-};
-
-PrintVisitor.prototype.block = function(block) {
-  var out = "";
-
-  out = out + this.pad("BLOCK:");
-  this.padding++;
-  out = out + this.accept(block.mustache);
-  if (block.program) {
-    out = out + this.pad("PROGRAM:");
-    this.padding++;
-    out = out + this.accept(block.program);
-    this.padding--;
-  }
-  if (block.inverse) {
-    if (block.program) { this.padding++; }
-    out = out + this.pad("{{^}}");
-    this.padding++;
-    out = out + this.accept(block.inverse);
-    this.padding--;
-    if (block.program) { this.padding--; }
-  }
-  this.padding--;
-
-  return out;
-};
-
-PrintVisitor.prototype.sexpr = function(sexpr) {
-  var params = sexpr.params, paramStrings = [], hash;
-
-  for(var i=0, l=params.length; i<l; i++) {
-    paramStrings.push(this.accept(params[i]));
-  }
-
-  params = "[" + paramStrings.join(", ") + "]";
-
-  hash = sexpr.hash ? " " + this.accept(sexpr.hash) : "";
-
-  return this.accept(sexpr.id) + " " + params + hash;
-};
-
-PrintVisitor.prototype.mustache = function(mustache) {
-  return this.pad("{{ " + this.accept(mustache.sexpr) + " }}");
-};
-
-PrintVisitor.prototype.partial = function(partial) {
-  var content = this.accept(partial.partialName);
-  if(partial.context) {
-    content += " " + this.accept(partial.context);
-  }
-  if (partial.hash) {
-    content += " " + this.accept(partial.hash);
-  }
-  return this.pad("{{> " + content + " }}");
-};
-
-PrintVisitor.prototype.hash = function(hash) {
-  var pairs = hash.pairs;
-  var joinedPairs = [], left, right;
-
-  for(var i=0, l=pairs.length; i<l; i++) {
-    left = pairs[i][0];
-    right = this.accept(pairs[i][1]);
-    joinedPairs.push( left + "=" + right );
-  }
-
-  return "HASH{" + joinedPairs.join(", ") + "}";
-};
-
-PrintVisitor.prototype.STRING = function(string) {
-  return '"' + string.string + '"';
-};
-
-PrintVisitor.prototype.NUMBER = function(number) {
-  return "NUMBER{" + number.number + "}";
-};
-
-PrintVisitor.prototype.BOOLEAN = function(bool) {
-  return "BOOLEAN{" + bool.bool + "}";
-};
-
-PrintVisitor.prototype.ID = function(id) {
-  var path = id.parts.join("/");
-  if(id.parts.length > 1) {
-    return "PATH:" + path;
-  } else {
-    return "ID:" + path;
-  }
-};
-
-PrintVisitor.prototype.PARTIAL_NAME = function(partialName) {
-    return "PARTIAL:" + partialName.name;
-};
-
-PrintVisitor.prototype.DATA = function(data) {
-  return "@" + this.accept(data.id);
-};
-
-PrintVisitor.prototype.content = function(content) {
-  return this.pad("CONTENT[ '" + content.string + "' ]");
-};
-
-PrintVisitor.prototype.comment = function(comment) {
-  return this.pad("{{! '" + comment.comment + "' }}");
-};
-

lib/handlebars/compiler/visitor.js

@@ -1,11 +0,0 @@
-function Visitor() {}
-
-Visitor.prototype = {
-  constructor: Visitor,
-
-  accept: function(object) {
-    return this[object.type](object);
-  }
-};
-
-export default Visitor;

lib/handlebars/decorators.js

@@ -0,0 +1,5 @@
+import registerInline from './decorators/inline';
+
+export function registerDefaultDecorators(instance) {
+  registerInline(instance);
+}

lib/handlebars/decorators/inline.js

@@ -0,0 +1,25 @@
+import { extend } from '../utils';
+
+export default function (instance) {
+  instance.registerDecorator(
+    'inline',
+    function (fn, props, container, options) {
+      let ret = fn;
+      if (!props.partials) {
+        props.partials = {};
+        ret = function (context, options) {
+          // Create a new partials stack frame prior to exec.
+          let original = container.partials;
+          container.partials = extend({}, original, props.partials);
+          let ret = fn(context, options);
+          container.partials = original;
+          return ret;
+        };
+      }
+
+      props.partials[options.args[0]] = options.fn;
+
+      return ret;
+    }
+  );
+}

lib/handlebars/exception.js

@@ -1,27 +0,0 @@
-
-var errorProps = ['description', 'fileName', 'lineNumber', 'message', 'name', 'number', 'stack'];
-
-function Exception(message, node) {
-  var line;
-  if (node && node.firstLine) {
-    line = node.firstLine;
-
-    message += ' - ' + line + ':' + node.firstColumn;
-  }
-
-  var tmp = Error.prototype.constructor.call(this, message);
-
-  // Unfortunately errors are not enumerable in Chrome (at least), so `for prop in tmp` doesn't work.
-  for (var idx = 0; idx < errorProps.length; idx++) {
-    this[errorProps[idx]] = tmp[errorProps[idx]];
-  }
-
-  if (line) {
-    this.lineNumber = line;
-    this.column = node.firstColumn;
-  }
-}
-
-Exception.prototype = new Error();
-
-export default Exception;

lib/handlebars/helpers.js

@@ -0,0 +1,27 @@
+import registerBlockHelperMissing from './helpers/block-helper-missing';
+import registerEach from './helpers/each';
+import registerHelperMissing from './helpers/helper-missing';
+import registerIf from './helpers/if';
+import registerLog from './helpers/log';
+import registerLookup from './helpers/lookup';
+import registerWith from './helpers/with';
+
+export function registerDefaultHelpers(instance) {
+  registerBlockHelperMissing(instance);
+  registerEach(instance);
+  registerHelperMissing(instance);
+  registerIf(instance);
+  registerLog(instance);
+  registerLookup(instance);
+  registerWith(instance);
+}
+
+export function moveHelperToHooks(instance, helperName, keepHelper) {
+  if (instance.helpers[helperName]) {
+    instance.hooks[helperName] = instance.helpers[helperName];
+    if (!keepHelper) {
+      // Using delete is slow
+      instance.helpers[helperName] = undefined;
+    }
+  }
+}

lib/handlebars/helpers/block-helper-missing.js

@@ -0,0 +1,22 @@
+import { isArray } from '../utils';
+
+export default function (instance) {
+  instance.registerHelper('blockHelperMissing', function (context, options) {
+    let inverse = options.inverse,
+      fn = options.fn;
+
+    if (context === true) {
+      return fn(this);
+    } else if (context === false || context == null) {
+      return inverse(this);
+    } else if (isArray(context)) {
+      if (context.length > 0) {
+        return instance.helpers.each(context, options);
+      } else {
+        return inverse(this);
+      }
+    } else {
+      return fn(context, options);
+    }
+  });
+}

lib/handlebars/helpers/each.js

@@ -0,0 +1,92 @@
+import { Exception } from '@handlebars/parser';
+import { createFrame, isArray, isFunction, isMap, isSet } from '../utils';
+
+export default function (instance) {
+  instance.registerHelper('each', function (context, options) {
+    if (!options) {
+      throw new Exception('Must pass iterator to #each');
+    }
+
+    let fn = options.fn,
+      inverse = options.inverse,
+      i = 0,
+      ret = '',
+      data;
+
+    if (isFunction(context)) {
+      context = context.call(this);
+    }
+
+    if (options.data) {
+      data = createFrame(options.data);
+    }
+
+    function execIteration(field, value, index, last) {
+      if (data) {
+        data.key = field;
+        data.index = index;
+        data.first = index === 0;
+        data.last = !!last;
+      }
+
+      ret =
+        ret +
+        fn(value, {
+          data: data,
+          blockParams: [context[field], field],
+        });
+    }
+
+    if (context && typeof context === 'object') {
+      if (isArray(context)) {
+        for (let j = context.length; i < j; i++) {
+          if (i in context) {
+            execIteration(i, context[i], i, i === context.length - 1);
+          }
+        }
+      } else if (isMap(context)) {
+        const j = context.size;
+        for (const [key, value] of context) {
+          execIteration(key, value, i++, i === j);
+        }
+      } else if (isSet(context)) {
+        const j = context.size;
+        for (const value of context) {
+          execIteration(i, value, i++, i === j);
+        }
+      } else if (typeof Symbol === 'function' && context[Symbol.iterator]) {
+        const newContext = [];
+        const iterator = context[Symbol.iterator]();
+        for (let it = iterator.next(); !it.done; it = iterator.next()) {
+          newContext.push(it.value);
+        }
+        context = newContext;
+        for (let j = context.length; i < j; i++) {
+          execIteration(i, context[i], i, i === context.length - 1);
+        }
+      } else {
+        let priorKey;
+
+        Object.keys(context).forEach((key) => {
+          // We're running the iterations one step out of sync so we can detect
+          // the last iteration without have to scan the object twice and create
+          // an intermediate keys array.
+          if (priorKey !== undefined) {
+            execIteration(priorKey, context[priorKey], i - 1);
+          }
+          priorKey = key;
+          i++;
+        });
+        if (priorKey !== undefined) {
+          execIteration(priorKey, context[priorKey], i - 1, true);
+        }
+      }
+    }
+
+    if (i === 0) {
+      ret = inverse(this);
+    }
+
+    return ret;
+  });
+}

lib/handlebars/helpers/helper-missing.js

@@ -0,0 +1,15 @@
+import { Exception } from '@handlebars/parser';
+
+export default function (instance) {
+  instance.registerHelper('helperMissing', function (/* [args, ]options */) {
+    if (arguments.length === 1) {
+      // A missing field in a {{foo}} construct.
+      return undefined;
+    } else {
+      // Someone is actually trying to call something, blow up.
+      throw new Exception(
+        'Missing helper: "' + arguments[arguments.length - 1].name + '"'
+      );
+    }
+  });
+}

lib/handlebars/helpers/if.js

@@ -0,0 +1,33 @@
+import { Exception } from '@handlebars/parser';
+import { isEmpty, isFunction } from '../utils';
+
+export default function (instance) {
+  instance.registerHelper('if', function (conditional, options) {
+    if (arguments.length != 2) {
+      throw new Exception('#if requires exactly one argument');
+    }
+    if (isFunction(conditional)) {
+      conditional = conditional.call(this);
+    }
+
+    // Default behavior is to render the positive path if the value is truthy and not empty.
+    // The `includeZero` option may be set to treat the conditional as purely not empty based on the
+    // behavior of isEmpty. Effectively this determines if 0 is handled by the positive path or negative.
+    if ((!options.hash.includeZero && !conditional) || isEmpty(conditional)) {
+      return options.inverse(this);
+    } else {
+      return options.fn(this);
+    }
+  });
+
+  instance.registerHelper('unless', function (conditional, options) {
+    if (arguments.length != 2) {
+      throw new Exception('#unless requires exactly one argument');
+    }
+    return instance.helpers['if'].call(this, conditional, {
+      fn: options.inverse,
+      inverse: options.fn,
+      hash: options.hash,
+    });
+  });
+}

lib/handlebars/helpers/log.js

@@ -0,0 +1,19 @@
+export default function (instance) {
+  instance.registerHelper('log', function (/* message, options */) {
+    let args = [undefined],
+      options = arguments[arguments.length - 1];
+    for (let i = 0; i < arguments.length - 1; i++) {
+      args.push(arguments[i]);
+    }
+
+    let level = 1;
+    if (options.hash.level != null) {
+      level = options.hash.level;
+    } else if (options.data && options.data.level != null) {
+      level = options.data.level;
+    }
+    args[0] = level;
+
+    instance.log(...args);
+  });
+}

lib/handlebars/helpers/lookup.js

@@ -0,0 +1,9 @@
+export default function (instance) {
+  instance.registerHelper('lookup', function (obj, field, options) {
+    if (!obj) {
+      // Note for 5.0: Change to "obj == null" in 5.0
+      return obj;
+    }
+    return options.lookupProperty(obj, field);
+  });
+}

lib/handlebars/helpers/with.js

@@ -0,0 +1,26 @@
+import { Exception } from '@handlebars/parser';
+import { isEmpty, isFunction } from '../utils';
+
+export default function (instance) {
+  instance.registerHelper('with', function (context, options) {
+    if (arguments.length != 2) {
+      throw new Exception('#with requires exactly one argument');
+    }
+    if (isFunction(context)) {
+      context = context.call(this);
+    }
+
+    let fn = options.fn;
+
+    if (!isEmpty(context)) {
+      let data = options.data;
+
+      return fn(context, {
+        data: data,
+        blockParams: [context],
+      });
+    } else {
+      return options.inverse(this);
+    }
+  });
+}

lib/handlebars/internal/proto-access.js

@@ -0,0 +1,68 @@
+import { extend } from '../utils';
+import logger from '../logger';
+
+const loggedProperties = Object.create(null);
+
+export function createProtoAccessControl(runtimeOptions) {
+  // Create an object with "null"-prototype to avoid truthy results on
+  // prototype properties.
+  const propertyWhiteList = Object.create(null);
+  // eslint-disable-next-line no-proto
+  propertyWhiteList['__proto__'] = false;
+  extend(propertyWhiteList, runtimeOptions.allowedProtoProperties);
+
+  const methodWhiteList = Object.create(null);
+  methodWhiteList['constructor'] = false;
+  methodWhiteList['__defineGetter__'] = false;
+  methodWhiteList['__defineSetter__'] = false;
+  methodWhiteList['__lookupGetter__'] = false;
+  extend(methodWhiteList, runtimeOptions.allowedProtoMethods);
+
+  return {
+    properties: {
+      whitelist: propertyWhiteList,
+      defaultValue: runtimeOptions.allowProtoPropertiesByDefault,
+    },
+    methods: {
+      whitelist: methodWhiteList,
+      defaultValue: runtimeOptions.allowProtoMethodsByDefault,
+    },
+  };
+}
+
+export function resultIsAllowed(result, protoAccessControl, propertyName) {
+  if (typeof result === 'function') {
+    return checkWhiteList(protoAccessControl.methods, propertyName);
+  } else {
+    return checkWhiteList(protoAccessControl.properties, propertyName);
+  }
+}
+
+function checkWhiteList(protoAccessControlForType, propertyName) {
+  if (protoAccessControlForType.whitelist[propertyName] !== undefined) {
+    return protoAccessControlForType.whitelist[propertyName] === true;
+  }
+  if (protoAccessControlForType.defaultValue !== undefined) {
+    return protoAccessControlForType.defaultValue;
+  }
+  logUnexpectedPropertyAccessOnce(propertyName);
+  return false;
+}
+
+function logUnexpectedPropertyAccessOnce(propertyName) {
+  if (loggedProperties[propertyName] !== true) {
+    loggedProperties[propertyName] = true;
+    logger.log(
+      'error',
+      `Handlebars: Access has been denied to resolve the property "${propertyName}" because it is not an "own property" of its parent.\n` +
+        `You can add a runtime option to disable the check or this warning:\n` +
+        `See https://handlebarsjs.com/api-reference/runtime-options.html#options-to-control-prototype-access for details`
+    );
+  }
+}
+
+export function resetLoggedProperties() {
+  Object.keys(loggedProperties).forEach((propertyName) => {
+    delete loggedProperties[propertyName];
+  });
+}

lib/handlebars/internal/wrapHelper.js

@@ -0,0 +1,13 @@
+export function wrapHelper(helper, transformOptionsFn) {
+  if (typeof helper !== 'function') {
+    // This should not happen, but apparently it does in https://github.com/handlebars-lang/handlebars.js/issues/1639
+    // We try to make the wrapper least-invasive by not wrapping it, if the helper is not a function.
+    return helper;
+  }
+  let wrapper = function (/* dynamic arguments */) {
+    const options = arguments[arguments.length - 1];
+    arguments[arguments.length - 1] = transformOptionsFn(options);
+    return helper.apply(this, arguments);
+  };
+  return wrapper;
+}

lib/handlebars/logger.js

@@ -0,0 +1,39 @@
+import { indexOf } from './utils';
+
+let logger = {
+  methodMap: ['debug', 'info', 'warn', 'error'],
+  level: 'info',
+
+  // Maps a given level value to the `methodMap` indexes above.
+  lookupLevel: function (level) {
+    if (typeof level === 'string') {
+      let levelMap = indexOf(logger.methodMap, level.toLowerCase());
+      if (levelMap >= 0) {
+        level = levelMap;
+      } else {
+        level = parseInt(level, 10);
+      }
+    }
+
+    return level;
+  },
+
+  // Can be overridden in the host environment
+  log: function (level, ...message) {
+    level = logger.lookupLevel(level);
+
+    if (
+      typeof console !== 'undefined' &&
+      logger.lookupLevel(logger.level) <= level
+    ) {
+      let method = logger.methodMap[level];
+      // eslint-disable-next-line no-console
+      if (!console[method]) {
+        method = 'log';
+      }
+      console[method](...message); // eslint-disable-line no-console
+    }
+  },
+};
+
+export default logger;

lib/handlebars/no-conflict.js

@@ -0,0 +1,11 @@
+export default function (Handlebars) {
+  let $Handlebars = globalThis.Handlebars;
+
+  /* v8 ignore next */
+  Handlebars.noConflict = function () {
+    if (globalThis.Handlebars === Handlebars) {
+      globalThis.Handlebars = $Handlebars;
+    }
+    return Handlebars;
+  };
+}

lib/handlebars/runtime.js

@@ -1,165 +1,390 @@
-module Utils from "./utils";
-import Exception from "./exception";
-import { COMPILER_REVISION, REVISION_CHANGES, createFrame } from "./base";
+import { Exception } from '@handlebars/parser';
+import * as Utils from './utils';
+import {
+  COMPILER_REVISION,
+  createFrame,
+  LAST_COMPATIBLE_COMPILER_REVISION,
+  REVISION_CHANGES,
+} from './base';
+import { moveHelperToHooks } from './helpers';
+import { wrapHelper } from './internal/wrapHelper';
+import {
+  createProtoAccessControl,
+  resultIsAllowed,
+} from './internal/proto-access';
 
 export function checkRevision(compilerInfo) {
-  var compilerRevision = compilerInfo && compilerInfo[0] || 1,
-      currentRevision = COMPILER_REVISION;
+  const compilerRevision = (compilerInfo && compilerInfo[0]) || 1,
+    currentRevision = COMPILER_REVISION;
 
-  if (compilerRevision !== currentRevision) {
-    if (compilerRevision < currentRevision) {
-      var runtimeVersions = REVISION_CHANGES[currentRevision],
-          compilerVersions = REVISION_CHANGES[compilerRevision];
-      throw new Exception("Template was precompiled with an older version of Handlebars than the current runtime. "+
-            "Please update your precompiler to a newer version ("+runtimeVersions+") or downgrade your runtime to an older version ("+compilerVersions+").");
-    } else {
-      // Use the embedded version info since the runtime doesn't know about this revision yet
-      throw new Exception("Template was precompiled with a newer version of Handlebars than the current runtime. "+
-            "Please update your runtime to a newer version ("+compilerInfo[1]+").");
-    }
+  if (
+    compilerRevision >= LAST_COMPATIBLE_COMPILER_REVISION &&
+    compilerRevision <= COMPILER_REVISION
+  ) {
+    return;
+  }
+
+  if (compilerRevision < LAST_COMPATIBLE_COMPILER_REVISION) {
+    const runtimeVersions = REVISION_CHANGES[currentRevision],
+      compilerVersions = REVISION_CHANGES[compilerRevision];
+    throw new Exception(
+      'Template was precompiled with an older version of Handlebars than the current runtime. ' +
+        'Please update your precompiler to a newer version (' +
+        runtimeVersions +
+        ') or downgrade your runtime to an older version (' +
+        compilerVersions +
+        ').'
+    );
+  } else {
+    // Use the embedded version info since the runtime doesn't know about this revision yet
+    throw new Exception(
+      'Template was precompiled with a newer version of Handlebars than the current runtime. ' +
+        'Please update your runtime to a newer version (' +
+        compilerInfo[1] +
+        ').'
+    );
   }
 }
 
-// TODO: Remove this line and break up compilePartial
-
 export function template(templateSpec, env) {
+  /* v8 ignore next */
   if (!env) {
-    throw new Exception("No environment passed to template");
+    throw new Exception('No environment passed to template');
+  }
+  if (!templateSpec || !templateSpec.main) {
+    throw new Exception('Unknown template object: ' + typeof templateSpec);
   }
 
+  templateSpec.main.decorator = templateSpec.main_d;
+
   // Note: Using env.VM references rather than local var references throughout this section to allow
-  // for external users to override these as psuedo-supported APIs.
+  // for external users to override these as pseudo-supported APIs.
   env.VM.checkRevision(templateSpec.compiler);
 
-  var invokePartialWrapper = function(partial, name, context, hash, helpers, partials, data) {
-    if (hash) {
-      context = Utils.extend({}, context, hash);
+  // backwards compatibility for precompiled templates with compiler-version 7 (<4.3.0)
+  const templateWasPrecompiledWithCompilerV7 =
+    templateSpec.compiler && templateSpec.compiler[0] === 7;
+
+  function invokePartialWrapper(partial, context, options) {
+    if (options.hash) {
+      context = Utils.extend({}, context, options.hash);
     }
+    partial = env.VM.resolvePartial.call(this, partial, context, options);
 
-    var result = env.VM.invokePartial.call(this, partial, name, context, helpers, partials, data);
-    if (result != null) { return result; }
+    options.hooks = this.hooks;
+    options.protoAccessControl = this.protoAccessControl;
 
-    if (env.compile) {
-      var options = { helpers: helpers, partials: partials, data: data };
-      partials[name] = env.compile(partial, { data: data !== undefined }, env);
-      return partials[name](context, options);
+    let result = env.VM.invokePartial.call(this, partial, context, options);
+
+    if (result == null && env.compile) {
+      options.partials[options.name] = env.compile(
+        partial,
+        templateSpec.compilerOptions,
+        env
+      );
+      result = options.partials[options.name](context, options);
+    }
+    if (result != null) {
+      if (options.indent) {
+        let lines = result.split('\n');
+        for (let i = 0, l = lines.length; i < l; i++) {
+          if (!lines[i] && i + 1 === l) {
+            break;
+          }
+
+          lines[i] = options.indent + lines[i];
+        }
+        result = lines.join('\n');
+      }
+      return result;
     } else {
-      throw new Exception("The partial " + name + " could not be compiled when running in runtime-only mode");
+      throw new Exception(
+        'The partial ' +
+          options.name +
+          ' could not be compiled when running in runtime-only mode'
+      );
     }
-  };
+  }
 
   // Just add water
-  var container = {
+  let container = {
+    strict: function (obj, name, loc) {
+      if (!obj || !(name in obj)) {
+        throw new Exception('"' + name + '" not defined in ' + obj, {
+          loc: loc,
+        });
+      }
+      return container.lookupProperty(obj, name);
+    },
+    lookupProperty: function (parent, propertyName) {
+      if (Utils.isMap(parent)) {
+        return parent.get(propertyName);
+      }
+
+      let result = parent[propertyName];
+      if (result == null) {
+        return result;
+      }
+      if (Object.prototype.hasOwnProperty.call(parent, propertyName)) {
+        return result;
+      }
+
+      if (resultIsAllowed(result, container.protoAccessControl, propertyName)) {
+        return result;
+      }
+      return undefined;
+    },
+    lookup: function (depths, name) {
+      const len = depths.length;
+      for (let i = 0; i < len; i++) {
+        let result = depths[i] && container.lookupProperty(depths[i], name);
+        if (result != null) {
+          return depths[i][name];
+        }
+      }
+    },
+    lambda: function (current, context) {
+      return typeof current === 'function' ? current.call(context) : current;
+    },
+
     escapeExpression: Utils.escapeExpression,
     invokePartial: invokePartialWrapper,
 
-    fn: function(i) {
-      return templateSpec[i];
-    },
-
-    programs: [],
-    program: function(i, data) {
-      var programWrapper = this.programs[i],
-          fn = this.fn(i);
-      if(data) {
-        programWrapper = program(this, i, fn, data);
-      } else if (!programWrapper) {
-        programWrapper = this.programs[i] = program(this, i, fn);
-      }
-      return programWrapper;
-    },
-    programWithDepth: env.VM.programWithDepth,
-
-    data: function(data, depth) {
-      while (data && depth--) {
-        data = data._parent;
-      }
-      return data;
-    },
-    merge: function(param, common) {
-      var ret = param || common;
-
-      if (param && common && (param !== common)) {
-        ret = Utils.extend({}, common, param);
-      }
-
+    fn: function (i) {
+      let ret = templateSpec[i];
+      ret.decorator = templateSpec[i + '_d'];
       return ret;
     },
 
+    programs: [],
+    program: function (i, data, declaredBlockParams, blockParams, depths) {
+      let programWrapper = this.programs[i],
+        fn = this.fn(i);
+      if (data || depths || blockParams || declaredBlockParams) {
+        programWrapper = wrapProgram(
+          this,
+          i,
+          fn,
+          data,
+          declaredBlockParams,
+          blockParams,
+          depths
+        );
+      } else if (!programWrapper) {
+        programWrapper = this.programs[i] = wrapProgram(this, i, fn);
+      }
+      return programWrapper;
+    },
+
+    data: function (value, depth) {
+      while (value && depth--) {
+        value = value._parent;
+      }
+      return value;
+    },
+    mergeIfNeeded: function (param, common) {
+      let obj = param || common;
+
+      if (param && common && param !== common) {
+        obj = Utils.extend({}, common, param);
+      }
+
+      return obj;
+    },
+    // An empty object to use as replacement for null-contexts
+    nullContext: Object.seal({}),
+
     noop: env.VM.noop,
-    compilerInfo: templateSpec.compiler
+    compilerInfo: templateSpec.compiler,
   };
 
-  var ret = function(context, options) {
-    options = options || {};
-    var helpers,
-        partials,
-        data = options.data;
+  function ret(context, options = {}) {
+    let data = options.data;
 
-    ret._setup(options);
+    _setup(options);
     if (!options.partial && templateSpec.useData) {
       data = initData(context, data);
     }
-    return templateSpec.main.call(container, context, container.helpers, container.partials, data);
-  };
+    let depths,
+      blockParams = templateSpec.useBlockParams ? [] : undefined;
+    if (templateSpec.useDepths) {
+      if (options.depths) {
+        depths =
+          context != options.depths[0]
+            ? [context].concat(options.depths)
+            : options.depths;
+      } else {
+        depths = [context];
+      }
+    }
 
-  ret._setup = function(options) {
+    function main(context /*, options*/) {
+      return (
+        '' +
+        templateSpec.main(
+          container,
+          context,
+          container.helpers,
+          container.partials,
+          data,
+          blockParams,
+          depths
+        )
+      );
+    }
+
+    main = executeDecorators(
+      templateSpec.main,
+      main,
+      container,
+      options.depths || [],
+      data,
+      blockParams
+    );
+    return main(context, options);
+  }
+
+  ret.isTop = true;
+
+  function _setup(options) {
     if (!options.partial) {
-      container.helpers = container.merge(options.helpers, env.helpers);
+      let mergedHelpers = {};
+      addHelpers(mergedHelpers, env.helpers, container);
+      addHelpers(mergedHelpers, options.helpers, container);
+      container.helpers = mergedHelpers;
 
       if (templateSpec.usePartial) {
-        container.partials = container.merge(options.partials, env.partials);
+        // Use mergeIfNeeded here to prevent compiling global partials multiple times
+        container.partials = container.mergeIfNeeded(
+          options.partials,
+          env.partials
+        );
       }
+      if (templateSpec.usePartial || templateSpec.useDecorators) {
+        container.decorators = Utils.extend(
+          {},
+          env.decorators,
+          options.decorators
+        );
+      }
+
+      container.hooks = {};
+      container.protoAccessControl = createProtoAccessControl(options);
+
+      let keepHelperInHelpers =
+        options.allowCallsToHelperMissing ||
+        templateWasPrecompiledWithCompilerV7;
+      moveHelperToHooks(container, 'helperMissing', keepHelperInHelpers);
+      moveHelperToHooks(container, 'blockHelperMissing', keepHelperInHelpers);
     } else {
+      container.protoAccessControl = options.protoAccessControl; // internal option
       container.helpers = options.helpers;
       container.partials = options.partials;
+      container.decorators = options.decorators;
+      container.hooks = options.hooks;
     }
-  };
+  }
 
-  ret._child = function(i) {
-    return container.programWithDepth(i);
-  };
   return ret;
 }
 
-export function programWithDepth(i, data /*, $depth */) {
-  /*jshint -W040 */
-  var args = Array.prototype.slice.call(arguments, 2),
-      container = this,
-      fn = container.fn(i);
+export function wrapProgram(
+  container,
+  i,
+  fn,
+  data,
+  declaredBlockParams,
+  blockParams,
+  depths
+) {
+  function prog(context, options = {}) {
+    let currentDepths = depths;
+    if (
+      depths &&
+      context != depths[0] &&
+      !(context === container.nullContext && depths[0] === null)
+    ) {
+      currentDepths = [context].concat(depths);
+    }
 
-  var prog = function(context, options) {
-    options = options || {};
+    return fn(
+      container,
+      context,
+      container.helpers,
+      container.partials,
+      options.data || data,
+      blockParams && [options.blockParams].concat(blockParams),
+      currentDepths
+    );
+  }
+
+  prog = executeDecorators(fn, prog, container, depths, data, blockParams);
 
-    return fn.apply(container, [context, container.helpers, container.partials, options.data || data].concat(args));
-  };
   prog.program = i;
-  prog.depth = args.length;
+  prog.depth = depths ? depths.length : 0;
+  prog.blockParams = declaredBlockParams || 0;
   return prog;
 }
 
-export function program(container, i, fn, data) {
-  var prog = function(context, options) {
-    options = options || {};
-
-    return fn.call(container, context, container.helpers, container.partials, options.data || data);
-  };
-  prog.program = i;
-  prog.depth = 0;
-  return prog;
+/**
+ * This is currently part of the official API, therefore implementation details should not be changed.
+ */
+export function resolvePartial(partial, context, options) {
+  if (!partial) {
+    if (options.name === '@partial-block') {
+      partial = options.data['partial-block'];
+    } else {
+      partial = options.partials[options.name];
+    }
+  } else if (!partial.call && !options.name) {
+    // This is a dynamic partial that returned a string
+    options.name = partial;
+    partial = options.partials[partial];
+  }
+  return partial;
 }
 
-export function invokePartial(partial, name, context, helpers, partials, data) {
-  var options = { partial: true, helpers: helpers, partials: partials, data: data };
+export function invokePartial(partial, context, options) {
+  // Use the current closure context to save the partial-block if this partial
+  const currentPartialBlock = options.data && options.data['partial-block'];
+  options.partial = true;
 
-  if(partial === undefined) {
-    throw new Exception("The partial " + name + " could not be found");
-  } else if(partial instanceof Function) {
+  let partialBlock;
+  if (options.fn && options.fn !== noop) {
+    options.data = createFrame(options.data);
+    // Wrapper function to get access to currentPartialBlock from the closure
+    let fn = options.fn;
+    partialBlock = options.data['partial-block'] = function partialBlockWrapper(
+      context,
+      options = {}
+    ) {
+      // Restore the partial-block from the closure for the execution of the block
+      // i.e. the part inside the block of the partial call.
+      options.data = createFrame(options.data);
+      options.data['partial-block'] = currentPartialBlock;
+      return fn(context, options);
+    };
+    if (fn.partials) {
+      options.partials = Utils.extend({}, options.partials, fn.partials);
+    }
+  }
+
+  if (partial === undefined && partialBlock) {
+    partial = partialBlock;
+  }
+
+  if (partial === undefined) {
+    throw new Exception(
+      'The partial "' + options.name + '" could not be found'
+    );
+  } else if (partial instanceof Function) {
     return partial(context, options);
   }
 }
 
-export function noop() { return ""; }
+export function noop() {
+  return '';
+}
 
 function initData(context, data) {
   if (!data || !('root' in data)) {
@@ -168,3 +393,36 @@ function initData(context, data) {
   }
   return data;
 }
+
+function executeDecorators(fn, prog, container, depths, data, blockParams) {
+  if (fn.decorator) {
+    let props = {};
+    prog = fn.decorator(
+      prog,
+      props,
+      container,
+      depths && depths[0],
+      data,
+      blockParams,
+      depths
+    );
+    Utils.extend(prog, props);
+  }
+  return prog;
+}
+
+function addHelpers(mergedHelpers, helpers, container) {
+  if (!helpers) return;
+  Object.keys(helpers).forEach((helperName) => {
+    let helper = helpers[helperName];
+    mergedHelpers[helperName] = passLookupPropertyOption(helper, container);
+  });
+}
+
+function passLookupPropertyOption(helper, container) {
+  const lookupProperty = container.lookupProperty;
+  return wrapHelper(helper, (options) => {
+    options.lookupProperty = lookupProperty;
+    return options;
+  });
+}

lib/handlebars/safe-string.js

@@ -3,8 +3,8 @@ function SafeString(string) {
   this.string = string;
 }
 
-SafeString.prototype.toString = function() {
-  return "" + this.string;
+SafeString.prototype.toString = SafeString.prototype.toHTML = function () {
+  return '' + this.string;
 };
 
 export default SafeString;

lib/handlebars/utils.js

@@ -1,25 +1,23 @@
-/*jshint -W004 */
-import SafeString from "./safe-string";
-
-var escape = {
-  "&": "&",
-  "<": "&lt;",
-  ">": "&gt;",
-  '"': "&quot;",
-  "'": "&#x27;",
-  "`": "&#x60;"
+const escape = {
+  '&': '&amp;',
+  '<': '&lt;',
+  '>': '&gt;',
+  '"': '&quot;',
+  "'": '&#x27;',
+  '`': '&#x60;',
+  '=': '&#x3D;',
 };
 
-var badChars = /[&<>"'`]/g;
-var possible = /[&<>"'`]/;
+const badChars = /[&<>"'`=]/g,
+  possible = /[&<>"'`=]/;
 
 function escapeChar(chr) {
-  return escape[chr] || "&amp;";
+  return escape[chr];
 }
 
 export function extend(obj /* , ...source */) {
-  for (var i = 1; i < arguments.length; i++) {
-    for (var key in arguments[i]) {
+  for (let i = 1; i < arguments.length; i++) {
+    for (let key in arguments[i]) {
       if (Object.prototype.hasOwnProperty.call(arguments[i], key)) {
         obj[key] = arguments[i][key];
       }
@@ -29,40 +27,57 @@ export function extend(obj /* , ...source */) {
   return obj;
 }
 
-export var toString = Object.prototype.toString;
+export let toString = Object.prototype.toString;
 
 // Sourced from lodash
-// https://github.com/bestiejs/lodash/blob/master/LICENSE.txt
-var isFunction = function(value) {
+// https://github.com/lodash/lodash/blob/4.17.21/LICENSE
+export function isFunction(value) {
   return typeof value === 'function';
-};
-// fallback for older versions of Chrome and Safari
-if (isFunction(/x/)) {
-  isFunction = function(value) {
-    return typeof value === 'function' && toString.call(value) === '[object Function]';
+}
+
+function testTag(name) {
+  const tag = '[object ' + name + ']';
+  return function (value) {
+    return value && typeof value === 'object'
+      ? toString.call(value) === tag
+      : false;
   };
 }
-export var isFunction;
 
-export var isArray = Array.isArray || function(value) {
-  return (value && typeof value === 'object') ? toString.call(value) === '[object Array]' : false;
-};
+export const isArray = Array.isArray;
+export const isMap = testTag('Map');
+export const isSet = testTag('Set');
 
+// Older IE versions do not directly support indexOf so we must implement our own, sadly.
+export function indexOf(array, value) {
+  for (let i = 0, len = array.length; i < len; i++) {
+    if (array[i] === value) {
+      return i;
+    }
+  }
+  return -1;
+}
 
 export function escapeExpression(string) {
-  // don't escape SafeStrings, since they're already safe
-  if (string instanceof SafeString) {
-    return string.toString();
-  } else if (!string && string !== 0) {
-    return "";
+  if (typeof string !== 'string') {
+    // don't escape SafeStrings, since they're already safe
+    if (string && string.toHTML) {
+      return string.toHTML();
+    } else if (string == null) {
+      return '';
+    } else if (!string) {
+      return string + '';
+    }
+
+    // Force a string conversion as this will be done by the append regardless and
+    // the regex test will do this transparently behind the scenes, causing issues if
+    // an object's to string has escaped characters in it.
+    string = '' + string;
   }
 
-  // Force a string conversion as this will be done by the append regardless and
-  // the regex test will do this transparently behind the scenes, causing issues if
-  // an object's to string has escaped characters in it.
-  string = "" + string;
-
-  if(!possible.test(string)) { return string; }
+  if (!possible.test(string)) {
+    return string;
+  }
   return string.replace(badChars, escapeChar);
 }
 
@@ -76,6 +91,8 @@ export function isEmpty(value) {
   }
 }
 
-export function appendContextPath(contextPath, id) {
-  return (contextPath ? contextPath + '.' : '') + id;
+export function createFrame(object) {
+  let frame = extend({}, object);
+  frame._parent = object;
+  return frame;
 }

lib/index.js

@@ -1,25 +1,25 @@
 // USAGE:
 // var handlebars = require('handlebars');
+/* eslint-disable no-var */
 
 // var local = handlebars.create();
 
-var handlebars = require('../dist/cjs/handlebars')["default"];
+var handlebars = require('../dist/cjs/handlebars')['default'];
 
-handlebars.Visitor = require('../dist/cjs/handlebars/compiler/visitor')["default"];
-
-var printer = require('../dist/cjs/handlebars/compiler/printer');
-handlebars.PrintVisitor = printer.PrintVisitor;
-handlebars.print = printer.print;
+var parser = require('@handlebars/parser');
+handlebars.PrintVisitor = parser.PrintVisitor;
+handlebars.print = parser.print;
 
 module.exports = handlebars;
 
 // Publish a Node.js require() handler for .handlebars and .hbs files
-if (typeof require !== 'undefined' && require.extensions) {
-  var extension = function(module, filename) {
-    var fs = require("fs");
-    var templateString = fs.readFileSync(filename, "utf8");
-    module.exports = handlebars.compile(templateString);
-  };
-  require.extensions[".handlebars"] = extension;
-  require.extensions[".hbs"] = extension;
+function extension(module, filename) {
+  var fs = require('fs');
+  var templateString = fs.readFileSync(filename, 'utf8');
+  module.exports = handlebars.compile(templateString);
+}
+/* v8 ignore next 4 */
+if (typeof require !== 'undefined' && require.extensions) {
+  require.extensions['.handlebars'] = extension;
+  require.extensions['.hbs'] = extension;
 }

lib/precompiler.js

@@ -0,0 +1,344 @@
+/* eslint-disable no-console */
+import Async from 'neo-async';
+import fs from 'fs';
+import Handlebars from './handlebars';
+import { basename } from 'path';
+import { SourceMapConsumer, SourceNode } from 'source-map';
+
+module.exports.loadTemplates = function (opts, callback) {
+  loadStrings(opts, function (err, strings) {
+    if (err) {
+      callback(err);
+    } else {
+      loadFiles(opts, function (err, files) {
+        if (err) {
+          callback(err);
+        } else {
+          opts.templates = strings.concat(files);
+          callback(undefined, opts);
+        }
+      });
+    }
+  });
+};
+
+function loadStrings(opts, callback) {
+  let strings = arrayCast(opts.string),
+    names = arrayCast(opts.name);
+
+  if (names.length !== strings.length && strings.length > 1) {
+    return callback(
+      new Handlebars.Exception(
+        'Number of names did not match the number of string inputs'
+      )
+    );
+  }
+
+  Async.map(
+    strings,
+    function (string, callback) {
+      if (string !== '-') {
+        callback(undefined, string);
+      } else {
+        // Load from stdin
+        let buffer = '';
+        process.stdin.setEncoding('utf8');
+
+        process.stdin.on('data', function (chunk) {
+          buffer += chunk;
+        });
+        process.stdin.on('end', function () {
+          callback(undefined, buffer);
+        });
+      }
+    },
+    function (err, strings) {
+      strings = strings.map((string, index) => ({
+        name: names[index],
+        path: names[index],
+        source: string,
+      }));
+      callback(err, strings);
+    }
+  );
+}
+
+function loadFiles(opts, callback) {
+  // Build file extension pattern
+  let extension = (opts.extension || 'handlebars').replace(
+    /[\\^$*+?.():=!|{}\-[\]]/g,
+    function (arg) {
+      return '\\' + arg;
+    }
+  );
+  extension = new RegExp('\\.' + extension + '$');
+
+  let ret = [],
+    queue = (opts.files || []).map((template) => ({
+      template,
+      root: opts.root,
+    }));
+  Async.whilst(
+    () => queue.length,
+    function (callback) {
+      let { template: path, root } = queue.shift();
+
+      fs.stat(path, function (err, stat) {
+        if (err) {
+          return callback(
+            new Handlebars.Exception(`Unable to open template file "${path}"`)
+          );
+        }
+
+        if (stat.isDirectory()) {
+          opts.hasDirectory = true;
+
+          fs.readdir(path, function (err, children) {
+            /* v8 ignore next -- Race condition that being too lazy to test */
+            if (err) {
+              return callback(err);
+            }
+            children.forEach(function (file) {
+              let childPath = path + '/' + file;
+
+              if (
+                extension.test(childPath) ||
+                fs.statSync(childPath).isDirectory()
+              ) {
+                queue.push({ template: childPath, root: root || path });
+              }
+            });
+
+            callback();
+          });
+        } else {
+          fs.readFile(path, 'utf8', function (err, data) {
+            /* v8 ignore next -- Race condition that being too lazy to test */
+            if (err) {
+              return callback(err);
+            }
+
+            if (opts.bom && data.indexOf('\uFEFF') === 0) {
+              data = data.substring(1);
+            }
+
+            // Clean the template name
+            let name = path;
+            if (!root) {
+              name = basename(name);
+            } else if (name.indexOf(root) === 0) {
+              name = name.substring(root.length + 1);
+            }
+            name = name.replace(extension, '');
+
+            ret.push({
+              path: path,
+              name: name,
+              source: data,
+            });
+
+            callback();
+          });
+        }
+      });
+    },
+    function (err) {
+      if (err) {
+        callback(err);
+      } else {
+        callback(undefined, ret);
+      }
+    }
+  );
+}
+
+module.exports.cli = async function (opts) {
+  if (opts.version) {
+    console.log(Handlebars.VERSION);
+    return;
+  }
+
+  if (!opts.templates.length && !opts.hasDirectory) {
+    throw new Handlebars.Exception(
+      'Must define at least one template or directory.'
+    );
+  }
+
+  if (opts.simple && opts.min) {
+    throw new Handlebars.Exception('Unable to minimize simple output');
+  }
+
+  const multiple = opts.templates.length !== 1 || opts.hasDirectory;
+  if (opts.simple && multiple) {
+    throw new Handlebars.Exception(
+      'Unable to output multiple templates in simple mode'
+    );
+  }
+
+  // Force simple mode if we have only one template and it's unnamed.
+  if (
+    !opts.amd &&
+    !opts.commonjs &&
+    opts.templates.length === 1 &&
+    !opts.templates[0].name
+  ) {
+    opts.simple = true;
+  }
+
+  // Convert the known list into a hash
+  let known = {};
+  if (opts.known && !Array.isArray(opts.known)) {
+    opts.known = [opts.known];
+  }
+  if (opts.known) {
+    for (let i = 0, len = opts.known.length; i < len; i++) {
+      known[opts.known[i]] = true;
+    }
+  }
+
+  const objectName = opts.partial ? 'Handlebars.partials' : 'templates';
+
+  let output = new SourceNode();
+  if (!opts.simple) {
+    if (opts.amd) {
+      output.add(
+        "define(['" +
+          opts.handlebarPath +
+          'handlebars.runtime\'], function(Handlebars) {\n  Handlebars = Handlebars["default"];'
+      );
+    } else if (opts.commonjs) {
+      output.add('var Handlebars = require("' + opts.commonjs + '");');
+    } else {
+      output.add('(function() {\n');
+    }
+    output.add('  var template = Handlebars.template, templates = ');
+    if (opts.namespace) {
+      output.add(opts.namespace);
+      output.add(' = ');
+      output.add(opts.namespace);
+      output.add(' || ');
+    }
+    output.add('{};\n');
+  }
+
+  for (const template of opts.templates) {
+    let options = {
+      knownHelpers: known,
+      knownHelpersOnly: opts.o,
+    };
+
+    if (opts.map) {
+      options.srcName = template.path;
+    }
+    if (opts.data) {
+      options.data = true;
+    }
+
+    let precompiled = Handlebars.precompile(template.source, options);
+
+    // If we are generating a source map, we have to reconstruct the SourceNode object
+    if (opts.map) {
+      let consumer = await new SourceMapConsumer(precompiled.map);
+      precompiled = SourceNode.fromStringWithSourceMap(
+        precompiled.code,
+        consumer
+      );
+      consumer.destroy();
+    }
+
+    if (opts.simple) {
+      output.add([precompiled, '\n']);
+    } else {
+      if (!template.name) {
+        throw new Handlebars.Exception('Name missing for template');
+      }
+
+      if (opts.amd && !multiple) {
+        output.add('return ');
+      }
+      output.add([
+        objectName,
+        "['",
+        template.name,
+        "'] = template(",
+        precompiled,
+        ');\n',
+      ]);
+    }
+  }
+
+  // Output the content
+  if (!opts.simple) {
+    if (opts.amd) {
+      if (multiple) {
+        output.add(['return ', objectName, ';\n']);
+      }
+      output.add('});');
+    } else if (!opts.commonjs) {
+      output.add('})();');
+    }
+  }
+
+  if (opts.map) {
+    output.add('\n//# sourceMappingURL=' + opts.map + '\n');
+  }
+
+  output = output.toStringWithSourceMap();
+  output.map = output.map + '';
+
+  if (opts.min) {
+    output = minify(output, opts.map);
+  }
+
+  if (opts.map) {
+    fs.writeFileSync(opts.map, output.map, 'utf8');
+  }
+  output = output.code;
+
+  if (opts.output) {
+    fs.writeFileSync(opts.output, output, 'utf8');
+  } else {
+    console.log(output);
+  }
+};
+
+function arrayCast(value) {
+  value = value != null ? value : [];
+  if (!Array.isArray(value)) {
+    value = [value];
+  }
+  return value;
+}
+
+/**
+ * Run uglify to minify the compiled template, if uglify exists in the dependencies.
+ *
+ * We are using `require` instead of `import` here, because es6-modules do not allow
+ * dynamic imports and uglify-js is an optional dependency. Since we are inside NodeJS here, this
+ * should not be a problem.
+ *
+ * @param {string} output the compiled template
+ * @param {string} sourceMapFile the file to write the source map to.
+ */
+function minify(output, sourceMapFile) {
+  try {
+    // Try to resolve uglify-js in order to see if it does exist
+    require.resolve('uglify-js');
+  } catch (e) {
+    if (e.code !== 'MODULE_NOT_FOUND') {
+      // Something else seems to be wrong
+      throw e;
+    }
+    // it does not exist!
+    console.error(
+      'Code minimization is disabled due to missing uglify-js dependency'
+    );
+    return output;
+  }
+  return require('uglify-js').minify(output.code, {
+    sourceMap: {
+      content: output.map,
+      url: sourceMapFile,
+    },
+  });
+}

package.json

@@ -1,61 +1,129 @@
 {
   "name": "handlebars",
-  "barename": "handlebars",
-  "version": "2.0.0-alpha.4",
+  "version": "5.0.0-alpha.1",
   "description": "Handlebars provides the power necessary to let you build semantic templates effectively with no frustration",
-  "homepage": "http://www.handlebarsjs.com/",
   "keywords": [
     "handlebars",
+    "html",
     "mustache",
-    "template",
-    "html"
+    "template"
   ],
+  "homepage": "https://handlebarsjs.com/",
+  "license": "MIT",
+  "author": "Yehuda Katz",
   "repository": {
     "type": "git",
-    "url": "https://github.com/wycats/handlebars.js.git"
+    "url": "https://github.com/handlebars-lang/handlebars.js.git"
   },
-  "author": "Yehuda Katz",
-  "license": "MIT",
-  "readmeFilename": "README.md",
-  "engines": {
-    "node": ">=0.4.7"
+  "bin": {
+    "handlebars": "bin/handlebars.mjs"
+  },
+  "files": [
+    "bin",
+    "dist/*.js",
+    "dist/cjs/**/*.js",
+    "lib",
+    "release-notes.md",
+    "runtime.js",
+    "types/*.d.ts",
+    "runtime.d.ts"
+  ],
+  "main": "lib/index.js",
+  "browser": "./dist/cjs/handlebars.js",
+  "types": "types/index.d.ts",
+  "scripts": {
+    "clean": "node -e \"require('fs').rmSync('dist',{recursive:true,force:true});require('fs').rmSync('tmp',{recursive:true,force:true})\"",
+    "build:cjs": "swc lib --out-dir dist/cjs --strip-leading-paths --ignore \"**/index.js\"",
+    "build:bundles": "rspack build",
+    "build": "npm run clean && npm run build:cjs && npm run build:bundles",
+    "release": "npm run build",
+    "publish:aws": "npm run build && npm run test:tasks && node tasks/publish-to-aws.js",
+    "format": "oxfmt --write . && oxlint --fix .",
+    "lint": "npm run lint:oxlint && npm run lint:format && npm run lint:types && npm run lint:compat",
+    "lint:oxlint": "oxlint --max-warnings 0 .",
+    "lint:format": "oxfmt --check .",
+    "lint:types": "tstyche",
+    "lint:compat": "eslint",
+    "test": "npm run build && vitest run --project node --project tasks --project rspack --coverage",
+    "test:browser": "vitest run --project browser",
+    "test:unit": "vitest run --project node",
+    "test:tasks": "vitest run --project tasks",
+    "test:publish": "npm run build && vitest run --project publish",
+    "test:browser-smoke": "playwright test --config tests/browser/playwright.config.js",
+    "test:serve": "npx serve -l 9999 .",
+    "test:integration": "npm run build && ./tests/integration/run-integration-tests.sh",
+    "bench": "node tests/bench/perf.mjs",
+    "bench:compare": "node tests/bench/compare.mjs",
+    "bench:size": "node tests/bench/size.mjs",
+    "--- combined tasks ---": "",
+    "check-before-pull-request": "concurrently --kill-others-on-fail npm:lint npm:test"
   },
   "dependencies": {
-    "optimist": "~0.3"
-  },
-  "optionalDependencies": {
-    "uglify-js": "~2.3"
+    "@handlebars/parser": "^2.1.0",
+    "neo-async": "^2.6.2",
+    "source-map": "^0.7.6",
+    "yargs": "^18.0.0"
   },
   "devDependencies": {
-    "async": "~0.2.9",
-    "aws-sdk": "~1.5.0",
-    "benchmark": "~1.0",
-    "dustjs-linkedin": "~2.0.2",
-    "eco": "~1.1.0-rc-3",
-    "grunt": "~0.4.1",
-    "grunt-cli": "~0.1.10",
-    "grunt-contrib-clean": "~0.4.1",
-    "grunt-contrib-concat": "~0.3.0",
-    "grunt-contrib-connect": "~0.5.0",
-    "grunt-contrib-copy": "~0.4.1",
-    "grunt-contrib-jshint": "0.x",
-    "grunt-contrib-requirejs": "~0.4.1",
-    "grunt-contrib-uglify": "~0.2.2",
-    "grunt-contrib-watch": "~0.5.3",
-    "grunt-saucelabs": "~5.0.1",
-    "es6-module-packager": "1.x",
-    "jison": "~0.3.0",
-    "keen.io": "0.0.3",
-    "mocha": "*",
-    "mustache": "~0.7.2",
-    "semver": "~2.1.0",
-    "underscore": "~1.5.1"
+    "@aws-sdk/client-s3": "^3.1011.0",
+    "@playwright/test": "^1.58.2",
+    "@rspack/cli": "^1.7.8",
+    "@rspack/core": "^1.7.8",
+    "@swc/cli": "^0.8.0",
+    "@swc/core": "^1.15.18",
+    "@vitest/browser": "^4.0.18",
+    "@vitest/browser-playwright": "^4.0.18",
+    "@vitest/coverage-v8": "^4.0.18",
+    "cli-testlab": "^6.0.0",
+    "concurrently": "^5.0.0",
+    "eslint": "^10.0.3",
+    "eslint-plugin-compat": "^7.0.1",
+    "fs-extra": "^8.1.0",
+    "husky": "^3.1.0",
+    "lint-staged": "^16.3.2",
+    "mock-stdin": "^0.3.0",
+    "oxfmt": "^0.36.0",
+    "oxlint": "^1.51.0",
+    "semver": "^5.0.1",
+    "tinybench": "^6.0.0",
+    "tstyche": "^6.2.0",
+    "typescript": "^5.9.3",
+    "uglify-js": "^3.19.3",
+    "vitest": "^4.0.18"
   },
-  "main": "lib/index.js",
-  "bin": {
-    "handlebars": "bin/handlebars"
+  "peerDependencies": {
+    "uglify-js": "^3.19.3"
   },
-  "scripts": {
-    "test": "grunt"
+  "husky": {
+    "hooks": {
+      "pre-commit": "lint-staged"
+    }
+  },
+  "lint-staged": {
+    "*.{js,css,json,md}": [
+      "oxfmt --write"
+    ],
+    "*.js": [
+      "oxlint --fix"
+    ]
+  },
+  "browserslist": [
+    "last 2 versions",
+    "Firefox ESR",
+    "not dead",
+    "not IE 11",
+    "maintained node versions"
+  ],
+  "engines": {
+    "node": ">=20"
+  },
+  "jspm": {
+    "main": "handlebars",
+    "directories": {
+      "lib": "dist/cjs"
+    },
+    "buildConfig": {
+      "minify": true
+    }
   }
 }

rspack.config.js

@@ -0,0 +1,88 @@
+const { rspack } = require('@rspack/core');
+const path = require('path');
+const fs = require('fs');
+
+const pkg = require('./package.json');
+const license = fs.readFileSync(path.resolve(__dirname, 'LICENSE'), 'utf8');
+const banner = `/*!
+
+ @license magnet:?xt=urn:btih:d3d9a9a6595521f9666a5e94cc830dab83b65699&dn=expat.txt Expat
+ ${pkg.name} v${pkg.version}
+
+${license}
+*/`;
+
+function createConfig(entry, filename, minimize) {
+  const plugins = [];
+
+  if (!minimize) {
+    // For non-minified builds, use BannerPlugin to add the license header
+    plugins.push(new rspack.BannerPlugin({ banner, raw: true }));
+  }
+
+  return {
+    mode: minimize ? 'production' : 'none',
+    context: __dirname,
+    entry,
+    output: {
+      path: path.resolve(__dirname, 'dist'),
+      filename,
+      library: {
+        name: 'Handlebars',
+        type: 'umd',
+        export: 'default',
+      },
+      globalObject: 'this',
+      clean: false,
+    },
+    module: {
+      rules: [
+        {
+          test: /\.js$/,
+          exclude: /node_modules/,
+          use: {
+            loader: 'builtin:swc-loader',
+            options: {
+              jsc: {
+                parser: { syntax: 'ecmascript' },
+              },
+            },
+          },
+        },
+      ],
+    },
+    optimization: {
+      minimize,
+      minimizer: minimize
+        ? [
+            new rspack.SwcJsMinimizerRspackPlugin({
+              extractComments: false,
+              minimizerOptions: {
+                compress: { passes: 2 },
+                mangle: true,
+                format: {
+                  comments: false,
+                  // Prepend the license banner in the minified output
+                  preamble: banner,
+                },
+              },
+            }),
+          ]
+        : [],
+    },
+    plugins,
+    target: ['web', 'browserslist'],
+    devtool: false,
+  };
+}
+
+module.exports = [
+  createConfig('./lib/handlebars.js', 'handlebars.js', false),
+  createConfig('./lib/handlebars.runtime.js', 'handlebars.runtime.js', false),
+  createConfig('./lib/handlebars.js', 'handlebars.min.js', true),
+  createConfig(
+    './lib/handlebars.runtime.js',
+    'handlebars.runtime.min.js',
+    true
+  ),
+];

runtime.d.ts

@@ -0,0 +1,3 @@
+import Handlebars = require('handlebars');
+
+declare module 'handlebars/runtime' {}

runtime.js

@@ -1,3 +1,3 @@
 // Create a simple path alias to allow browserify to resolve
 // the runtime on a supported path.
-module.exports = require('./dist/cjs/handlebars.runtime');
+module.exports = require('./dist/cjs/handlebars.runtime')['default'];

spec/amd.html

@@ -1,109 +0,0 @@
-<html>
-  <head>
-    <title>Mocha</title>
-    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
-    <meta name="viewport" content="width=device-width, initial-scale=1.0">
-
-    <link rel="stylesheet" href="/node_modules/mocha/mocha.css" />
-    <style>
-      .headless .suite > h1,
-      .headless .test.pass {
-        display: none;
-      }
-    </style>
-
-    <script>
-      // Show only errors in "headless", non-interactive mode.
-      if (/headless=true/.test(location.href)) {
-        document.documentElement.className = 'headless';
-      }
-    </script>
-    <script src="/node_modules/mocha/mocha.js"></script>
-    <script>
-      mocha.setup('bdd');
-    </script>
-
-    <script src="/spec/env/json2.js"></script>
-    <script src="/spec/env/require.js"></script>
-
-    <script src="/spec/env/common.js"></script>
-    <script>
-      requirejs.config({
-        paths: {
-          handlebars: '/dist/handlebars.amd',
-          tests: '/tmp/tests'
-        }
-      });
-
-      var CompilerContext = {
-        compile: function(template, options) {
-          var templateSpec = handlebarsEnv.precompile(template, options);
-          return handlebarsEnv.template(safeEval(templateSpec));
-        },
-        compileWithPartial: function(template, options) {
-          return handlebarsEnv.compile(template, options);
-        }
-      };
-
-      function safeEval(templateSpec) {
-        try {
-          var ret;
-          eval('ret = ' + templateSpec);
-          return ret;
-        } catch (err) {
-          console.error(templateSpec);
-          throw err;
-        }
-      }
-    </script>
-    <script>
-      onload = function(){
-
-        require(['handlebars'], function(Handlebars) {
-          window.Handlebars = Handlebars['default'];
-
-          require(['tests'], function(Handlebars) {
-            mocha.globals(['mochaResults'])
-            // The test harness leaks under FF. We should have decent global leak coverage from other tests
-            if (!navigator.userAgent.match(/Firefox\/([\d.]+)/)) {
-              mocha.checkLeaks();
-            }
-            var runner = mocha.run();
-
-            //Reporting for saucelabs
-            var failedTests = [];
-            runner.on('end', function(){
-              window.mochaResults = runner.stats;
-              window.mochaResults.reports = failedTests;
-            });
-
-            runner.on('fail', logFailure);
-
-            function logFailure(test, err){
-
-              var flattenTitles = function(test){
-                var titles = [];
-                while (test.parent.title){
-                  titles.push(test.parent.title);
-                  test = test.parent;
-                }
-                return titles.reverse();
-              };
-
-              failedTests.push({
-                name: test.title,
-                result: false,
-                message: err.message,
-                stack: err.stack,
-                titles: flattenTitles(test)
-              });
-            };
-          });
-        });
-      };
-    </script>
-  </head>
-  <body>
-    <div id="mocha"></div>
-  </body>
-</html>

spec/artifacts/bom.handlebars

@@ -0,0 +1 @@
+a

spec/artifacts/known.helpers.handlebars

@@ -0,0 +1,6 @@
+{{#someHelper true}}
+ <div>Some known helper</div>
+    {{#anotherHelper true}}
+    <div>Another known helper</div>
+    {{/anotherHelper}}
+{{/someHelper}}

spec/artifacts/non.default.extension.hbs

@@ -0,0 +1 @@
+<div>This is a test</div>