wip: only run "require"-test, if "require-extensions" exists

"require" does not mean "amd" in this case...

.eslintignore

@@ -0,0 +1,25 @@
+.rvmrc
+.DS_Store
+/tmp/
+*.sublime-project
+*.sublime-workspace
+npm-debug.log
+sauce_connect.log*
+.idea
+yarn-error.log
+node_modules
+/handlebars-release.tgz
+.nyc_output
+
+# Generated files
+lib/handlebars/compiler/parser.js
+/coverage/
+/dist/
+/integration-testing/*/dist/
+
+# Third-party or files that must remain unchanged
+/spec/expected/
+/spec/vendor
+
+# JS-Snippets
+src/*.js

.eslintrc

@@ -1,200 +0,0 @@
-{
-  "globals": {
-    "self": false
-  },
-  "env": {
-    "node": true
-  },
-  "ecmaFeatures": {
-    // Enabling features that can be implemented without polyfills. Want to avoid polyfills at this time.
-    "arrowFunctions": true,
-    "blockBindings": true,
-    "defaultParams": true,
-    "destructuring": true,
-    "modules": true,
-    "objectLiteralComputedProperties": true,
-    "objectLiteralDuplicateProperties": true,
-    "objectLiteralShorthandMethods": true,
-    "objectLiteralShorthandProperties": true,
-    "restParams": true,
-    "spread": true,
-    "templateStrings": true
-  },
-  "rules": {
-    // Possible Errors //
-    //-----------------//
-
-    "comma-dangle": [2, "never"],
-    "no-cond-assign": [2, "except-parens"],
-
-    // Allow for debugging
-    "no-console": 1,
-
-    "no-constant-condition": 2,
-    "no-control-regex": 2,
-
-    // Allow for debugging
-    "no-debugger": 1,
-
-    "no-dupe-args": 2,
-    "no-dupe-keys": 2,
-    "no-duplicate-case": 2,
-    "no-empty": 2,
-    "no-empty-character-class": 2,
-    "no-ex-assign": 2,
-    "no-extra-boolean-cast": 2,
-    "no-extra-parens": 0,
-    "no-extra-semi": 2,
-    "no-func-assign": 0,
-
-    // Stylistic... might consider disallowing in the future
-    "no-inner-declarations": 0,
-
-    "no-invalid-regexp": 2,
-    "no-irregular-whitespace": 2,
-    "no-negated-in-lhs": 2,
-    "no-obj-calls": 2,
-    "no-regex-spaces": 2,
-    "quote-props": [2, "as-needed", {"keywords": true}],
-    "no-sparse-arrays": 0,
-
-    // Optimizer and coverage will handle/highlight this and can be useful for debugging
-    "no-unreachable": 1,
-
-    "use-isnan": 2,
-    "valid-jsdoc": 0,
-    "valid-typeof": 2,
-
-
-    // Best Practices //
-    //----------------//
-    "block-scoped-var": 0,
-    "complexity": 0,
-    "consistent-return": 0,
-    "curly": 2,
-    "default-case": 1,
-    "dot-notation": [2, {"allowKeywords": false}],
-    "eqeqeq": 0,
-    "guard-for-in": 1,
-    "no-alert": 2,
-    "no-caller": 2,
-    "no-div-regex": 1,
-    "no-else-return": 0,
-    "no-empty-label": 2,
-    "no-eq-null": 0,
-    "no-eval": 2,
-    "no-extend-native": 2,
-    "no-extra-bind": 2,
-    "no-fallthrough": 2,
-    "no-floating-decimal": 2,
-    "no-implied-eval": 2,
-    "no-iterator": 2,
-    "no-labels": 2,
-    "no-lone-blocks": 2,
-    "no-loop-func": 2,
-    "no-multi-spaces": 2,
-    "no-multi-str": 1,
-    "no-native-reassign": 2,
-    "no-new": 2,
-    "no-new-func": 2,
-    "no-new-wrappers": 2,
-    "no-octal": 2,
-    "no-octal-escape": 2,
-    "no-param-reassign": 0,
-    "no-process-env": 2,
-    "no-proto": 2,
-    "no-redeclare": 2,
-    "no-return-assign": 2,
-    "no-script-url": 2,
-    "no-self-compare": 2,
-    "no-sequences": 2,
-    "no-throw-literal": 2,
-    "no-unused-expressions": 2,
-    "no-void": 0,
-    "no-warning-comments": 1,
-    "no-with": 2,
-    "radix": 2,
-    "vars-on-top": 0,
-    "wrap-iife": 2,
-    "yoda": 0,
-
-
-    // Strict //
-    //--------//
-    "strict": 0,
-
-
-    // Variables //
-    //-----------//
-    "no-catch-shadow": 2,
-    "no-delete-var": 2,
-    "no-label-var": 2,
-    "no-shadow": 0,
-    "no-shadow-restricted-names": 2,
-    "no-undef": 2,
-    "no-undef-init": 2,
-    "no-undefined": 0,
-    "no-unused-vars": [2, {"vars": "all", "args": "after-used"}],    
-    "no-use-before-define": [2, "nofunc"],
-
-
-    // Node.js //
-    //---------//
-    // Others left to environment defaults
-    "no-mixed-requires": 0,
-
-
-    // Stylistic //
-    //-----------//
-    "indent": 0,
-    "brace-style": [2, "1tbs", {"allowSingleLine": true}],
-    "camelcase": 2,
-    "comma-spacing": [2, {"before": false, "after": true}],
-    "comma-style": [2, "last"],
-    "consistent-this": [1, "self"],
-    "eol-last": 2,
-    "func-names": 0,
-    "func-style": [2, "declaration"],
-    "key-spacing": [2, {
-        "beforeColon": false,
-        "afterColon": true
-    }],
-    "max-nested-callbacks": 0,
-    "new-cap": 2,
-    "new-parens": 2,
-    "newline-after-var": 0,
-    "no-array-constructor": 2,
-    "no-continue": 0,
-    "no-inline-comments": 0,
-    "no-lonely-if": 2,
-    "no-mixed-spaces-and-tabs": 2,
-    "no-multiple-empty-lines": 0,
-    "no-nested-ternary": 1,
-    "no-new-object": 2,
-    "no-spaced-func": 2,
-    "no-ternary": 0,
-    "no-trailing-spaces": 2,
-    "no-underscore-dangle": 0,
-    "no-extra-parens": [2, "functions"],
-    "one-var": 0,
-    "operator-assignment": 0,
-    "padded-blocks": 0,
-    "quote-props": 0,
-    "quotes": [2, "single", "avoid-escape"],
-    "semi": 2,
-    "semi-spacing": [2, {"before": false, "after": true}],
-    "sort-vars": 0,
-    "space-after-keywords": [2, "always"],
-    "space-before-blocks": [2, "always"],
-    "space-before-function-paren": [2, {"anonymous": "never", "named": "never"}],
-    "space-in-brackets": 0,
-    "space-in-parens": [2, "never"],
-    "space-infix-ops": 2,
-    "space-return-throw-case": 2,
-    "space-unary-ops": 2,
-    "spaced-comment": [2, "always", {"markers": [","]}],
-    "wrap-regex": 1,
-
-    "no-var": 1
-  }
-}

.eslintrc.js

@@ -0,0 +1,66 @@
+module.exports = {
+  extends: ['eslint:recommended', 'plugin:compat/recommended', 'prettier'],
+  globals: {
+    self: false
+  },
+  env: {
+    node: true,
+    es6: true
+  },
+  rules: {
+    'no-console': 'warn',
+
+    // temporarily disabled until the violating places are fixed.
+    'no-func-assign': 'off',
+    'no-sparse-arrays': 'off',
+
+    // Best Practices //
+    //----------------//
+    '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-floating-decimal': '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-octal-escape': 'error',
+    'no-process-env': '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',
+
+    // Variables //
+    //-----------//
+    'no-label-var': 'error',
+    'no-undef-init': 'error',
+    'no-use-before-define': ['error', 'nofunc'],
+
+    // ECMAScript 6 //
+    //--------------//
+    'no-var': 'error'
+  },
+  parserOptions: {
+    sourceType: 'module',
+    ecmaVersion: 2018,
+    ecmaFeatures: {}
+  }
+};

.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

.gitignore

@@ -1,12 +1,20 @@
-vendor
 .rvmrc
 .DS_Store
-lib/handlebars/compiler/parser.js
-/dist/
 /tmp/
-/coverage/
-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
+lib/handlebars/compiler/parser.js
+/coverage/
+/dist/
+/integration-testing/*/dist/
+/spec/tmp/*

.istanbul.yml

@@ -1,2 +0,0 @@
-instrumentation:
-    excludes: ['**/spec/**']

.npmignore

@@ -1,25 +0,0 @@
-.DS_Store
-.gitignore
-.rvmrc
-.eslintrc
-.travis.yml
-.rspec
-Gemfile
-Gemfile.lock
-Rakefile
-Gruntfile.js
-*.gemspec
-*.nuspec
-*.log
-bench/*
-configurations/*
-components/*
-coverage/*
-dist/cdnjs/*
-dist/components/*
-spec/*
-src/*
-tasks/*
-tmp/*
-publish/*
-vendor/*

.prettierignore

@@ -0,0 +1,22 @@
+.rvmrc
+.DS_Store
+/tmp/
+*.sublime-project
+*.sublime-workspace
+npm-debug.log
+sauce_connect.log*
+.idea
+yarn-error.log
+node_modules
+/handlebars-release.tgz
+.nyc_output
+
+# Generated files
+lib/handlebars/compiler/parser.js
+/coverage/
+/dist/
+/integration-testing/*/dist/
+
+# Third-party or files that must remain unchanged
+/spec/expected/
+/spec/vendor

.travis.yml

@@ -1,26 +1,39 @@
 language: node_js
-before_install:
-- npm install -g grunt-cli
-script:
-- grunt --stack travis
+jobs:
+  include:
+  - stage: test
+    name: check javascript (eslint)
+    node_js: lts/*
+    script: npm run lint
+  - stage: test
+    name: check formatting (prettier)
+    node_js: lts/*
+    script: npm run check-format
+  - stage: test
+    name: check typescript definitions (dtslint)
+    node_js: lts/*
+    script: npm run dtslint
+  - stage: test
+    name: extensive tests and publish to aws
+    script: npm run extensive-tests-and-publish-to-aws
+    env:
+    - S3_BUCKET_NAME=builds.handlebarsjs.com
+    - secure: ckyEe5dzjdFDjmZ6wIrhGm0CFBEnKq8c1dYptfgVV/Q5/nJFGzu8T0yTjouS/ERxzdT2H327/63VCxhFnLCRHrsh4rlW/rCy4XI3O/0TeMLgFPa4TXkO8359qZ4CB44TBb3NsJyQXNMYdJpPLTCVTMpuiqqkFFOr+6OeggR7ufA=
+    - secure: Nm4AgSfsgNB21kgKrF9Tl7qVZU8YYREhouQunFracTcZZh2NZ2XH5aHuSiXCj88B13Cr/jGbJKsZ4T3QS3wWYtz6lkyVOx3H3iI+TMtqhD9RM3a7A4O+4vVN8IioB2YjhEu0OKjwgX5gp+0uF+pLEi7Hpj6fupD3AbbL5uYcKg8=
+    - SAUCE_USERNAME=handlebars
+    - secure: 1VkLQhbsEug4ZMQ52tTOus/WLvW3Etqe7GbCzZfzsI8d2ygJPjFfzU8fNm4pVVwoTI21MaM5AQq7SVPu8DWN1YbDjJycMdY1zO3DsB9aZBxTal98fIB7ZIUce9r5z2EP6mETrsbYjZkeckzIBI0A4UVa+F2BO4KbRDXP1Db3u3I=
+    node_js: '10'
+  - stage: test
+    name: test with latest nodejs-lts
+    node_js: lts/*
+    script: npm run test
+  - stage: test
+    name: test with active nodejs
+    node_js: node
+    script: npm run test
+cache: npm
 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
-
 git:
   depth: 100

CONTRIBUTING.md

@@ -6,15 +6,22 @@ Please see our [FAQ](https://github.com/wycats/handlebars.js/blob/master/FAQ.md)
 
 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 thats demonstrating the issue are welcomed and this also helps ensure that your issue won't regress in the future once it's fixed.
+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 site should be reported on [handlebars-site](https://github.com/wycats/handlebars-site).
 
+## Branches
+
+- The branch `4.x` contains the currently released version. Bugfixes should be made in this branch.
+- The branch `master` contains the next version. A release date is not yet specified. Maintainers
+  should merge the branch `4.x` into the master branch regularly.
+
 ## 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)
@@ -25,8 +32,8 @@ Generally we like to see pull requests that
 
 To build Handlebars.js you'll need a few things installed.
 
-* Node.js
-* [Grunt](http://gruntjs.com/getting-started)
+- Node.js
+- [Grunt](http://gruntjs.com/getting-started)
 
 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`.
 
@@ -42,27 +49,64 @@ The `grunt dev` implements watching for tests and allows for in browser testing
 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).
 
-## Ember testing
+##Running Tests
 
-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.
+To run tests locally, first install all dependencies.
 
 ```sh
-npm link
-grunt build release
-cp dist/*.js $emberRepoDir/bower_components/handlebars/
+npm install
+```
 
-cd $emberRepoDir
-npm link handlebars
+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
 ```
 
-## Releasing
+## Linting and Formatting
+
+Handlebars uses `eslint` to enforce best-practices and `prettier` to auto-format files.
+We do linting and formatting in two phases:
+
+- Committed files are linted and formatted in a pre-commit hook. In this stage eslint-errors are forbidden,
+  while warnings are allowed.
+- The travis-ci job also lints all files and checks if they are formatted correctly. In this stage, warnings
+  are forbidden.
+
+You can use the following scripts to make sure that the travis-job does not fail:
+
+- **npm run lint** will run `eslint` and fail on warnings
+- **npm run format** will run `prettier` on all files
+- **npm run check-before-pull-request** will perform all most checks that travis does in its build-job, excluding the "integration-test".
+- **npm run integration-test** will run integration tests (using old NodeJS versions and integrations with webpack, babel and so on)
+  These tests only work on a Linux-machine with `nvm` installed (for running tests in multiple versions of NodeJS).
+
+## Releasing the latest version
+
+Before attempting the release Handlebars, please make sure that you have the following authorizations:
+
+- Push-access to `wycats/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._
 
 Handlebars utilizes the [release yeoman generator][generator-release] to perform most release tasks.
 
 A full release may be completed with the following:
 
 ```
+npm ci
 yo release
 npm publish
 yo release:publish components handlebars.js dist/components/
@@ -72,9 +116,23 @@ 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 link should be updated to point to the most recent distribution for all instances in our documentation.
+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/handlebarsjs.com-github-pages](https://github.com/handlebars-lang/handlebarsjs.com-github-pages/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/wycats/handlebars.js/pull/new/master
 [issue]: https://github.com/wycats/handlebars.js/issues/new
-[jsfiddle]: http://jsfiddle.net/9D88g/46/
+[jsfiddle]: https://jsfiddle.net/9D88g/180/

Gruntfile.js

@@ -1,44 +1,42 @@
 /* eslint-disable no-process-env */
 module.exports = function(grunt) {
-
   grunt.initConfig({
     pkg: grunt.file.readJSON('package.json'),
 
-    eslint: {
-      options: {
-      },
-      files: [
-        '*.js',
-        'bench/**/*.js',
-        'tasks/**/*.js',
-        'lib/**/!(*.min|parser).js',
-        'spec/**/!(*.amd|json2|require).js'
-      ]
-    },
-
-    clean: ['tmp', 'dist', 'lib/handlebars/compiler/parser.js'],
+    clean: [
+      'tmp',
+      'dist',
+      'lib/handlebars/compiler/parser.js',
+      'integration-testing/**/node_modules'
+    ],
 
     copy: {
       dist: {
         options: {
           processContent: function(content) {
-            return grunt.template.process('/*!\n\n <%= pkg.name %> v<%= pkg.version %>\n\n<%= grunt.file.read("LICENSE") %>\n@license\n*/\n')
-                + content;
+            return (
+              grunt.template.process(
+                '/**!\n\n @license\n <%= pkg.name %> v<%= pkg.version %>\n\n<%= grunt.file.read("LICENSE") %>\n*/\n'
+              ) + content
+            );
           }
         },
-        files: [
-          {expand: true, cwd: 'dist/', src: ['*.js'], dest: 'dist/'}
-        ]
+        files: [{ expand: true, cwd: 'dist/', src: ['*.js'], dest: 'dist/' }]
       },
       cdnjs: {
         files: [
-          {expand: true, cwd: 'dist/', src: ['*.js'], dest: 'dist/cdnjs'}
+          { 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'}
+          {
+            expand: true,
+            cwd: 'components/',
+            src: ['**'],
+            dest: 'dist/components'
+          },
+          { expand: true, cwd: 'dist/', src: ['*.js'], dest: 'dist/components' }
         ]
       }
     },
@@ -53,24 +51,28 @@ module.exports = function(grunt) {
         options: {
           modules: 'amd'
         },
-        files: [{
-          expand: true,
-          cwd: 'lib/',
-          src: '**/!(index).js',
-          dest: 'dist/amd/'
-        }]
+        files: [
+          {
+            expand: true,
+            cwd: 'lib/',
+            src: '**/!(index).js',
+            dest: 'dist/amd/'
+          }
+        ]
       },
 
       cjs: {
         options: {
           modules: 'common'
         },
-        files: [{
-          cwd: 'lib/',
-          expand: true,
-          src: '**/!(index).js',
-          dest: 'dist/cjs/'
-        }]
+        files: [
+          {
+            cwd: 'lib/',
+            expand: true,
+            src: '**/!(index).js',
+            dest: 'dist/cjs/'
+          }
+        ]
       }
     },
     webpack: {
@@ -79,7 +81,12 @@ module.exports = function(grunt) {
         module: {
           loaders: [
             // the optional 'runtime' transformer tells babel to require the runtime instead of inlining it.
-            { test: /\.jsx?$/, exclude: /node_modules/, loader: 'babel-loader?optional=runtime&loose=es6.modules&auxiliaryCommentBefore=istanbul%20ignore%20next' }
+            {
+              test: /\.jsx?$/,
+              exclude: /node_modules/,
+              loader:
+                'babel-loader?optional=runtime&loose=es6.modules&auxiliaryCommentBefore=istanbul%20ignore%20next'
+            }
           ]
         },
         output: {
@@ -125,18 +132,20 @@ module.exports = function(grunt) {
       options: {
         mangle: true,
         compress: true,
-        preserveComments: 'some'
+        preserveComments: /(?:^!|@(?:license|preserve|cc_on))/
       },
       dist: {
-        files: [{
-          cwd: 'dist/',
-          expand: true,
-          src: ['handlebars*.js', '!*.min.js'],
-          dest: 'dist/',
-          rename: function(dest, src) {
-            return dest + src.replace(/\.js$/, '.min.js');
+        files: [
+          {
+            cwd: 'dist/',
+            expand: true,
+            src: ['handlebars*.js', '!*.min.js'],
+            dest: 'dist/',
+            rename: function(dest, src) {
+              return dest + src.replace(/\.js$/, '.min.js');
+            }
           }
-        }]
+        ]
       }
     },
 
@@ -156,37 +165,80 @@ module.exports = function(grunt) {
         }
       }
     },
+    karma: {
+      options: {
+        configFile: 'karma.conf.js'
+      },
+      saucelabs: {
+        build: process.env.TRAVIS_JOB_ID || 'non-travis',
+        configFile: 'karma-setup/default/karma.conf.js',
+        ...require('./karma-setup/shared/saucelabs'),
+        singleRun: true
+      },
+      default: {
+        browsers: [],
+        configFile: 'karma-setup/default/karma.conf.js',
+        singleRun: false,
+        autoWatch: true
+      },
+      amd: {
+        configFile: 'karma-setup/amd/karma.conf.js',
+        browsers: [],
+        singleRun: false,
+        autoWatch: true
+      }
+    },
     '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'],
+          urls: [
+            'http://localhost:9999/spec/?headless=true',
+            'http://localhost:9999/spec/amd.html?headless=true'
+          ],
           detailedError: true,
           concurrency: 4,
           browsers: [
-            {browserName: 'chrome'},
-            {browserName: 'firefox', platform: 'Linux'},
-            {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: 'chrome' },
+            { browserName: 'firefox', platform: 'Linux' },
+            { browserName: 'safari', version: 9, platform: 'OS X 10.11' },
+            { browserName: 'safari', version: 8, platform: 'OS X 10.10' },
+            {
+              browserName: 'internet explorer',
+              version: 11,
+              platform: 'Windows 8.1'
+            },
+            {
+              browserName: 'internet explorer',
+              version: 10,
+              platform: 'Windows 8'
+            }
           ]
         }
       },
       sanity: {
         options: {
           build: process.env.TRAVIS_JOB_ID,
-          urls: ['http://localhost:9999/spec/umd.html?headless=true', 'http://localhost:9999/spec/amd-runtime.html?headless=true', 'http://localhost:9999/spec/umd-runtime.html?headless=true'],
+          urls: [
+            'http://localhost:9999/spec/umd.html?headless=true',
+            'http://localhost:9999/spec/amd-runtime.html?headless=true',
+            'http://localhost:9999/spec/umd-runtime.html?headless=true'
+          ],
           detailedError: true,
           concurrency: 2,
-          browsers: [
-            {browserName: 'chrome'}
-          ]
+          browsers: [{ browserName: 'chrome' }]
         }
       }
     },
 
+    bgShell: {
+      integrationTests: {
+        cmd: './integration-testing/run-integration-tests.sh',
+        bg: false,
+        fail: true
+      }
+    },
+
     watch: {
       scripts: {
         options: {
@@ -194,25 +246,11 @@ module.exports = function(grunt) {
         },
 
         files: ['src/*', 'lib/**/*.js', 'spec/**/*.js'],
-        tasks: ['build', 'amd', 'tests', 'test']
+        tasks: ['on-file-change']
       }
     }
   });
 
-  // Build a new version of the library
-  this.registerTask('build', 'Builds a distributable version of the current project', [
-                    'eslint',
-                    'parser',
-                    'node',
-                    'globals']);
-
-  this.registerTask('amd', ['babel:amd', 'requirejs']);
-  this.registerTask('node', ['babel:cjs']);
-  this.registerTask('globals', ['webpack']);
-  this.registerTask('tests', ['concat:tests']);
-
-  this.registerTask('release', 'Build final packages', ['eslint', 'amd', 'uglify', 'copy:dist', 'copy:components', 'copy:cdnjs']);
-
   // Load tasks from npm
   grunt.loadNpmTasks('grunt-contrib-clean');
   grunt.loadNpmTasks('grunt-contrib-concat');
@@ -222,17 +260,62 @@ module.exports = function(grunt) {
   grunt.loadNpmTasks('grunt-contrib-uglify');
   grunt.loadNpmTasks('grunt-contrib-watch');
   grunt.loadNpmTasks('grunt-babel');
-  grunt.loadNpmTasks('grunt-eslint');
-  grunt.loadNpmTasks('grunt-saucelabs');
+  grunt.loadNpmTasks('grunt-bg-shell');
+  grunt.loadNpmTasks('grunt-karma');
   grunt.loadNpmTasks('grunt-webpack');
 
   grunt.task.loadTasks('tasks');
 
+  this.registerTask(
+    'build',
+    'Builds a distributable version of the current project',
+    ['parser', 'node', 'globals']
+  );
+
+  this.registerTask('node', ['babel:cjs']);
+  this.registerTask('globals', ['webpack']);
+
+  this.registerTask('release', 'Build final packages', [
+    'amd',
+    'uglify',
+    'test:min',
+    'copy:dist',
+    'copy:components',
+    'copy:cdnjs'
+  ]);
+
+  this.registerTask('amd', ['babel:amd', 'requirejs']);
+
+  this.registerTask('test', ['test:bin', 'test:cov']);
+
   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']);
+  if (process.env.SAUCE_ACCESS_KEY) {
+    grunt.registerTask('sauce', ['karma:saucelabs']);
+  } else {
+    grunt.registerTask('sauce', []);
+  }
 
+  // Requires secret properties (saucelabs-credentials etc.) from .travis.yaml
+  grunt.registerTask('extensive-tests-and-publish-to-aws', [
+    'default',
+    'bgShell:integrationTests',
+    'sauce',
+    'metrics',
+    'publish-to-aws'
+  ]);
+  grunt.registerTask('on-file-change', [
+    'build',
+    'amd',
+    'concat:tests',
+    'test'
+  ]);
+
+  // === Primary tasks ===
   grunt.registerTask('dev', ['clean', 'connect', 'watch']);
   grunt.registerTask('default', ['clean', 'build', 'test', 'release']);
+  grunt.registerTask('integration-tests', [
+    'default',
+    'bgShell:integrationTests'
+  ]);
 };

LICENSE

@@ -1,4 +1,4 @@
-Copyright (C) 2011-2015 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

@@ -1,4 +1,5 @@
 [![Travis Build Status](https://img.shields.io/travis/wycats/handlebars.js/master.svg)](https://travis-ci.org/wycats/handlebars.js)
+[![Appveyor Build Status](https://ci.appveyor.com/api/projects/status/github/wycats/handlebars.js?branch=master&svg=true)](https://ci.appveyor.com/project/wycats/handlebars-js)
 [![Selenium Test Status](https://saucelabs.com/buildstatus/handlebars)](https://saucelabs.com/u/handlebars)
 
 Handlebars.js
@@ -10,12 +11,12 @@ 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) and the live demo at [http://tryhandlebarsjs.com/](http://tryhandlebarsjs.com/).
+[https://handlebarsjs.com/](https://handlebarsjs.com) and the live demo at [http://tryhandlebarsjs.com/](http://tryhandlebarsjs.com/).
 
 Installing
 ----------
 
-See our [installation documentation](http://handlebarsjs.com/installation.html).
+See our [installation documentation](https://handlebarsjs.com/installation/).
 
 Usage
 -----
@@ -45,23 +46,23 @@ var result = template(data);
 // </ul>
 ```
 
-Full documentation and more examples are at [handlebarsjs.com](http://handlebarsjs.com/).
+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](http://handlebarsjs.com/precompilation.html).
+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/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](http://handlebarsjs.com/#paths)
-- [Helpers](http://handlebarsjs.com/#helpers)
-- [Block Expressions](http://handlebarsjs.com/#block-expressions)
-- [Literal Values](http://handlebarsjs.com/#literals)
-- [Delimited Comments](http://handlebarsjs.com/#comments)
+- [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](http://mustache.github.io/mustache.5.html) defines the exact behavior of sections. In the case of name conflicts, helpers are given priority.
 
@@ -121,6 +122,7 @@ 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.
+* [Cory](https://github.com/leo/cory), by [@leo](https://github.com/leo), is another tiny static site generator
 * [CoSchedule](http://coschedule.com) An editorial calendar for WordPress that uses Handlebars.js
 * [dashbars](https://github.com/pismute/dashbars) A modern helper library for Handlebars.js.
 * [Ember.js](http://www.emberjs.com) makes Handlebars.js the primary way to
@@ -148,7 +150,9 @@ Handlebars in the Wild
   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
+* [DOMBars](https://github.com/blakeembrey/dombars) is a DOM-based templating engine built on the Handlebars parser and runtime **DEPRECATED**
+* [promised-handlebars](https://github.com/nknapp/promised-handlebars) is a wrapper for Handlebars that allows helpers to return Promises.
+* [just-handlebars-helpers](https://github.com/leapfrogtechnology/just-handlebars-helpers) A fully tested lightweight package with common Handlebars helpers.
 
 External Resources
 ------------------

appveyor.yml

@@ -0,0 +1,36 @@
+# Test against these versions of Node.js
+environment:
+  matrix:
+    - nodejs_version: "10"
+
+platform:
+  - x64
+
+# Install scripts (runs after repo cloning)
+install:
+  # Get the latest stable version of Node.js
+  - ps: Install-Product node $env:nodejs_version $env:platform
+  # Clone submodules (mustache spec)
+  - cmd: git submodule update --init --recursive
+  # Install modules
+  - cmd: npm ci
+
+
+# Post-install test scripts
+test_script:
+  # Output useful info for debugging
+  - cmd: node --version
+  - cmd: npm --version
+  # Run tests
+  - cmd: npm run test
+
+# Don't actually build
+build: off
+
+on_failure:
+  - cmd: 7z a coverage.zip coverage
+  - cmd: appveyor PushArtifact coverage.zip
+
+
+# Set build version format here instead of in the admin panel
+version: "{build}"

bench/.eslintrc

@@ -1,4 +1,5 @@
 {
+  "extends": "prettier",
   "globals": {
     "require": true
   },
@@ -11,4 +12,4 @@
     "handle-callback-err": 0,
     "no-console": 0
   }
-}
+}

bench/dist-size.js

@@ -1,12 +1,14 @@
-var async = require('async'),
-    fs = require('fs'),
-    zlib = require('zlib');
+var async = require('neo-async'),
+  fs = require('fs'),
+  zlib = require('zlib');
 
 module.exports = function(grunt, callback) {
   var distFiles = fs.readdirSync('dist'),
-      distSizes = {};
+    distSizes = {};
 
-  async.each(distFiles, function(file, callback) {
+  async.each(
+    distFiles,
+    function(file, callback) {
       var content;
       try {
         content = fs.readFileSync('dist/' + file);
@@ -32,7 +34,10 @@ module.exports = function(grunt, callback) {
       });
     },
     function() {
-      grunt.log.writeln('Distribution sizes: ' + JSON.stringify(distSizes, undefined, 2));
+      grunt.log.writeln(
+        'Distribution sizes: ' + JSON.stringify(distSizes, undefined, 2)
+      );
       callback([distSizes]);
-    });
+    }
+  );
 };

bench/index.js

@@ -2,7 +2,7 @@ var fs = require('fs');
 
 var metrics = fs.readdirSync(__dirname);
 metrics.forEach(function(metric) {
-  if (metric === 'index.js' || !(/(.*)\.js$/.test(metric))) {
+  if (metric === 'index.js' || !/(.*)\.js$/.test(metric)) {
     return;
   }
 

bench/precompile-size.js

@@ -1,5 +1,5 @@
 var _ = require('underscore'),
-    templates = require('./templates');
+  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
@@ -8,12 +8,17 @@ module.exports = function(grunt, callback) {
   var templateSizes = {};
   _.each(templates, function(info, template) {
     var src = info.handlebars,
-        compiled = Handlebars.precompile(src, {}),
-        knownHelpers = Handlebars.precompile(src, {knownHelpersOnly: true, knownHelpers: info.helpers});
+      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));
+  grunt.log.writeln(
+    'Precompiled sizes: ' + JSON.stringify(templateSizes, undefined, 2)
+  );
   callback([templateSizes]);
 };

bench/templates/arguments.js

@@ -8,5 +8,6 @@ module.exports = {
     bar: true
   },
 
-  handlebars: '{{foo person "person" 1 true foo=bar foo="person" foo=1 foo=true}}'
+  handlebars:
+    '{{foo person "person" 1 true foo=bar foo="person" foo=1 foo=true}}'
 };

bench/templates/array-each.js

@@ -1,5 +1,12 @@
 module.exports = {
-  context: { names: [{name: 'Moe'}, {name: 'Larry'}, {name: 'Curly'}, {name: 'Shemp'}] },
+  context: {
+    names: [
+      { name: 'Moe' },
+      { name: 'Larry' },
+      { name: 'Curly' },
+      { name: 'Shemp' }
+    ]
+  },
   handlebars: '{{#each names}}{{name}}{{/each}}',
   dust: '{#names}{name}{/names}',
   mustache: '{{#names}}{{name}}{{/names}}',

bench/templates/array-mustache.js

@@ -1,4 +1,11 @@
 module.exports = {
-  context: { names: [{name: 'Moe'}, {name: 'Larry'}, {name: 'Curly'}, {name: 'Shemp'}] },
+  context: {
+    names: [
+      { name: 'Moe' },
+      { name: 'Larry' },
+      { name: 'Curly' },
+      { name: 'Shemp' }
+    ]
+  },
   handlebars: '{{#names}}{{name}}{{/names}}'
 };

bench/templates/complex.js

@@ -5,11 +5,11 @@ module.exports = {
     header: function() {
       return 'Colors';
     },
-    hasItems: true,   // To make things fairer in mustache land due to no `{{if}}` construct on arrays
+    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'}
+      { name: 'red', current: true, url: '#Red' },
+      { name: 'green', current: false, url: '#Green' },
+      { name: 'blue', current: false, url: '#Blue' }
     ]
   },
 

bench/templates/data.js

@@ -1,4 +1,11 @@
 module.exports = {
-  context: { names: [{name: 'Moe'}, {name: 'Larry'}, {name: 'Curly'}, {name: 'Shemp'}] },
+  context: {
+    names: [
+      { name: 'Moe' },
+      { name: 'Larry' },
+      { name: 'Curly' },
+      { name: 'Shemp' }
+    ]
+  },
   handlebars: '{{#each names}}{{@index}}{{name}}{{/each}}'
 };

bench/templates/depth-1.js

@@ -1,5 +1,13 @@
 module.exports = {
-  context: { names: [{name: 'Moe'}, {name: 'Larry'}, {name: 'Curly'}, {name: 'Shemp'}], foo: 'bar' },
+  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 +1,16 @@
 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}}',
+  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 %>'
+  eco:
+    '<% for item in @names: %><% for child in item.name: %><%= item.bat %><%= @foo %><% end %><% end %>'
 };

bench/templates/index.js

@@ -2,7 +2,7 @@ var fs = require('fs');
 
 var templates = fs.readdirSync(__dirname);
 templates.forEach(function(template) {
-  if (template === 'index.js' || !(/(.*)\.js$/.test(template))) {
+  if (template === 'index.js' || !/(.*)\.js$/.test(template)) {
     return;
   }
   module.exports[RegExp.$1] = require('./' + RegExp.$1);

bench/templates/partial-recursion.js

@@ -1,5 +1,8 @@
 module.exports = {
-  context: { name: '1', kids: [{ name: '1.1', kids: [{name: '1.1.1', kids: []}] }] },
+  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}}' }

bench/templates/partial.js

@@ -1,8 +1,16 @@
 module.exports = {
-  context: { peeps: [{name: 'Moe', count: 15}, {name: 'Larry', count: 5}, {name: 'Curly', count: 1}] },
+  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: {
+      variables: 'Hello {{name}}! You have {{count}} new messages.'
+    }
   },
 
   handlebars: '{{#each peeps}}{{>variables}}{{/each}}',

bench/templates/paths.js

@@ -1,7 +1,9 @@
 module.exports = {
-  context: { person: { name: {bar: {baz: 'Larry'}}, age: 45 } },
-  handlebars: '{{person.name.bar.baz}}{{person.age}}{{person.foo}}{{animal.age}}',
+  context: { person: { name: { bar: { baz: 'Larry' } }, age: 45 } },
+  handlebars:
+    '{{person.name.bar.baz}}{{person.age}}{{person.foo}}{{animal.age}}',
   dust: '{person.name.bar.baz}{person.age}{person.foo}{animal.age}',
-  eco: '<%= @person.name.bar.baz %><%= @person.age %><%= @person.foo %><% if @animal: %><%= @animal.age %><% end %>',
+  eco:
+    '<%= @person.name.bar.baz %><%= @person.age %><%= @person.foo %><% if @animal: %><%= @animal.age %><% end %>',
   mustache: '{{person.name.bar.baz}}{{person.age}}{{person.foo}}{{animal.age}}'
 };

bench/templates/variables.js

@@ -1,8 +1,7 @@
 module.exports = {
-  context: {name: 'Mick', count: 30},
+  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

@@ -1,19 +1,27 @@
 var _ = require('underscore'),
-    runner = require('./util/template-runner'),
-
-    eco, dust, Handlebars, Mustache;
+  runner = require('./util/template-runner'),
+  eco,
+  dust,
+  Handlebars,
+  Mustache;
 
 try {
   dust = require('dustjs-linkedin');
-} catch (err) { /* NOP */ }
+} catch (err) {
+  /* NOP */
+}
 
 try {
   Mustache = require('mustache');
-} catch (err) { /* NOP */ }
+} catch (err) {
+  /* NOP */
+}
 
 try {
   eco = require('eco');
-} catch (err) { /* NOP */ }
+} catch (err) {
+  /* NOP */
+}
 
 function error() {
   throw new Error('EWOT');
@@ -22,21 +30,28 @@ function error() {
 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,
+    compatOut,
+    dustOut,
+    ecoOut,
+    mustacheOut;
 
-      context = template.context,
-      partials = template.partials,
-
-      handlebarsOut,
-      compatOut,
-      dustOut,
-      ecoOut,
-      mustacheOut;
-
-  var handlebar = Handlebars.compile(template.handlebars, {data: false}),
-      compat = Handlebars.compile(template.handlebars, {data: false, compat: true}),
-      options = {helpers: template.helpers};
-  _.each(template.partials && template.partials.handlebars, function(partial, partialName) {
-    Handlebars.registerPartial(partialName, Handlebars.compile(partial, {data: false}));
+  var handlebar = Handlebars.compile(template.handlebars, { data: false }),
+    compat = Handlebars.compile(template.handlebars, {
+      data: false,
+      compat: true
+    }),
+    options = { helpers: template.helpers };
+  _.each(template.partials && template.partials.handlebars, function(
+    partial,
+    partialName
+  ) {
+    Handlebars.registerPartial(
+      partialName,
+      Handlebars.compile(partial, { data: false })
+    );
   });
 
   handlebarsOut = handlebar(context, options);
@@ -58,7 +73,9 @@ function makeSuite(bench, name, template, handlebarsOnly) {
       dustOut = false;
       dust.loadSource(dust.compile(template.dust, templateName));
 
-      dust.render(templateName, context, function(err, out) { dustOut = out; });
+      dust.render(templateName, context, function(err, out) {
+        dustOut = out;
+      });
 
       bench('dust', function() {
         dust.render(templateName, context, function() {});
@@ -84,7 +101,7 @@ function makeSuite(bench, name, template, handlebarsOnly) {
 
   if (Mustache) {
     var mustacheSource = template.mustache,
-        mustachePartials = partials && partials.mustache;
+      mustachePartials = partials && partials.mustache;
 
     if (mustacheSource) {
       mustacheOut = Mustache.to_html(mustacheSource, context, mustachePartials);
@@ -107,9 +124,16 @@ function makeSuite(bench, name, template, handlebarsOnly) {
     b = b.replace(/\s/g, '');
 
     if (handlebarsOut !== b) {
-      throw new Error('Template output mismatch: ' + name
-            + '\n\nHandlebars: ' + handlebarsOut
-            + '\n\n' + lang + ': ' + b);
+      throw new Error(
+        'Template output mismatch: ' +
+          name +
+          '\n\nHandlebars: ' +
+          handlebarsOut +
+          '\n\n' +
+          lang +
+          ': ' +
+          b
+      );
     }
   }
 

bench/util/benchwarmer.js

@@ -1,5 +1,5 @@
 var _ = require('underscore'),
-    Benchmark = require('benchmark');
+  Benchmark = require('benchmark');
 
 function BenchWarmer() {
   this.benchmarks = [];
@@ -11,7 +11,7 @@ function BenchWarmer() {
   this.errors = {};
 }
 
-var print = require('sys').print;
+var print = require('util').print;
 
 BenchWarmer.prototype = {
   winners: function(benches) {
@@ -29,20 +29,25 @@ BenchWarmer.prototype = {
     });
   },
   push: function(name, fn) {
-    if (this.names.indexOf(name) == -1) {
+    if (this.names.indexOf(name) === -1) {
       this.names.push(name);
     }
 
-    var first = this.first, suiteName = this.suiteName, self = this;
+    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); }
+        if (first) {
+          self.startLine(suiteName);
+        }
         self.writeBench(bench);
         self.currentBenches.push(bench);
-      }, onError: function() {
+      },
+      onError: function() {
         self.errors[this.name] = this;
       }
     });
@@ -75,10 +80,14 @@ BenchWarmer.prototype = {
         });
         print('\n');
 
-        var errors = false, prop, bench;
+        var errors = false,
+          prop,
+          bench;
         for (prop in self.errors) {
-          if (self.errors.hasOwnProperty(prop)
-              && self.errors[prop].error.message !== 'EWOT') {
+          if (
+            Object.prototype.hasOwnProperty.call(self, prop) &&
+            self.errors[prop].error.message !== 'EWOT'
+          ) {
             errors = true;
             break;
           }
@@ -86,9 +95,8 @@ BenchWarmer.prototype = {
 
         if (errors) {
           print('\n\nErrors:\n');
-          for (prop in self.errors) {
-            if (self.errors.hasOwnProperty(prop)
-                && self.errors[prop].error.message !== 'EWOT') {
+          Object.keys(self.errors).forEach(function(prop) {
+            if (self.errors[prop].error.message !== 'EWOT') {
               bench = self.errors[prop];
               print('\n' + bench.name + ':\n');
               print(bench.error.message);
@@ -97,7 +105,7 @@ BenchWarmer.prototype = {
               }
               print('\n');
             }
-          }
+          });
         }
 
         callback();
@@ -108,23 +116,39 @@ BenchWarmer.prototype = {
   },
 
   scaleTimes: function() {
-    var scaled = this.scaled = {};
-    _.each(this.times, function(times, name) {
-      var output = scaled[name] = {};
+    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);
+        _.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;
+    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; }
+      if (benchSize < name.length) {
+        benchSize = name.length;
+      }
     }
 
     this.nameSize = benchSize + 2;
@@ -147,7 +171,9 @@ BenchWarmer.prototype = {
   },
 
   startLine: function(name) {
-    var winners = Benchmark.map(this.winners(this.currentBenches), function(bench) {
+    var winners = Benchmark.map(this.winners(this.currentBenches), function(
+      bench
+    ) {
       return bench.name.split(': ')[1];
     });
 
@@ -165,9 +191,9 @@ BenchWarmer.prototype = {
 
     if (!bench.error) {
       var count = bench.hz,
-          moe = count * bench.stats.rme / 100,
-          minimum,
-          maximum;
+        moe = (count * bench.stats.rme) / 100,
+        minimum,
+        maximum;
 
       count = Math.round(count / 1000);
       moe = Math.round(moe / 1000);

bench/util/template-runner.js

@@ -1,12 +1,12 @@
 var _ = require('underscore'),
-    BenchWarmer = require('./benchwarmer'),
-    templates = require('../templates');
+  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');
+    grep = grunt.option('grep');
   if (grep) {
     grep = new RegExp(grep);
   }

bin/.eslintrc.js

@@ -0,0 +1,6 @@
+module.exports = {
+  rules: {
+    'no-console': 0,
+    'no-var': 0
+  }
+};

bin/handlebars

@@ -1,128 +1,176 @@
 #!/usr/bin/env node
 
-var optimist = require('optimist')
-    .usage('Precompile handlebar templates.\nUsage: $0 [template|directory]...', {
-      'f': {
-        'type': 'string',
-        'description': 'Output File',
-        'alias': 'output'
-      },
-      'map': {
-        'type': 'string',
-        'description': 'Source Map File'
-      },
-      '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'
-      },
-      'N': {
-        'type': 'string',
-        'description': 'Name of passed string templates. Optional if running in a simple mode. Required when operating on multiple templates.',
-        'alias': 'name'
-      },
-      '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'
-      },
-      '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'
-      },
+var argv = parseArgs({
+  'f': {
+    'type': 'string',
+    'description': 'Output File',
+    'alias': 'output'
+  },
+  'map': {
+    'type': 'string',
+    'description': 'Source Map File'
+  },
+  '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'
+  },
+  'N': {
+    'type': 'string',
+    'description': 'Name of passed string templates. Optional if running in a simple mode. Required when operating on multiple templates.',
+    'alias': 'name'
+  },
+  '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'
+  },
+  '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'
+  },
+  'help': {
+    'type': 'boolean',
+    'description': 'Outputs this message'
+  }
+});
 
-      'help': {
-        'type': 'boolean',
-        'description': 'Outputs this message'
-      }
-    })
-
-    .wrap(120)
-    .check(function(argv) {
-      if (argv.version) {
-        return;
-      }
-    });
-
-
-var argv = optimist.argv;
 argv.files = argv._;
 delete argv._;
 
 var Precompiler = require('../dist/cjs/precompiler');
 Precompiler.loadTemplates(argv, function(err, opts) {
+
   if (err) {
     throw err;
   }
 
   if (opts.help || (!opts.templates.length && !opts.version)) {
-    optimist.showHelp();
+    printUsage(argv._spec, 120);
   } else {
     Precompiler.cli(opts);
   }
 });
+
+function pad(n) {
+  var str = '';
+  while (str.length < n) {
+    str += ' ';
+  }
+  return str;
+}
+
+function parseArgs(spec) {
+  var opts = { alias: {}, boolean: [], default: {}, string: [] };
+
+  Object.keys(spec).forEach(function (arg) {
+    var opt = spec[arg];
+    opts[opt.type].push(arg);
+    if ('alias' in opt) opts.alias[arg] = opt.alias;
+    if ('default' in opt) opts.default[arg] = opt.default;
+  });
+
+  var argv = require('minimist')(process.argv.slice(2), opts);
+  argv._spec = spec;
+  return argv;
+}
+
+function printUsage(spec, wrap) {
+  var wordwrap = require('wordwrap');
+
+  console.log('Precompile handlebar templates.');
+  console.log('Usage: handlebars [template|directory]...');
+
+  var opts = [];
+  var width = 0;
+  Object.keys(spec).forEach(function (arg) {
+    var opt = spec[arg];
+
+    var name = (arg.length === 1 ? '-' : '--') + arg;
+    if ('alias' in opt) name += ', --' + opt.alias;
+
+    var meta = '[' + opt.type + ']';
+    if ('default' in opt) meta += ' [default: ' + JSON.stringify(opt.default) + ']';
+
+    opts.push({ name: name, desc: opt.description, meta: meta });
+    if (name.length > width) width = name.length;
+  });
+
+  console.log('Options:');
+  opts.forEach(function (opt) {
+    var desc = wordwrap(width + 4, wrap + 1)(opt.desc);
+
+    console.log('  %s%s%s%s%s',
+      opt.name,
+      pad(width - opt.name.length + 2),
+      desc.slice(width + 4),
+      pad(wrap - opt.meta.length - desc.split(/\n/).pop().length),
+      opt.meta
+      );
+  });
+}

components/bower.json

@@ -1,6 +1,6 @@
 {
   "name": "handlebars",
-  "version": "4.0.1",
+  "version": "4.7.6",
   "main": "handlebars.js",
   "license": "MIT",
   "dependencies": {}

components/handlebars.js.nuspec

@@ -2,7 +2,7 @@
 <package>
 	<metadata>
 		<id>handlebars.js</id>
-		<version>4.0.1</version>
+		<version>4.7.6</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>

components/package.json

@@ -0,0 +1,20 @@
+{
+  "name": "handlebars",
+  "version": "4.7.6",
+  "license": "MIT",
+  "jspm": {
+    "main": "handlebars",
+    "shim": {
+      "handlebars": {
+        "exports": "Handlebars"
+      }
+    },
+    "files": [
+      "handlebars.js",
+      "handlebars.runtime.js"
+    ],
+    "buildConfig": {
+      "minify": true
+    }
+  }
+}

docs/compiler-api.md

@@ -16,6 +16,34 @@ var ast = Handlebars.parse(myTemplate);
 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
 
@@ -66,7 +94,7 @@ interface MustacheStatement <: Statement {
 
 interface BlockStatement <: Statement {
     type: "BlockStatement";
-    path: PathExpression;
+    path: PathExpression | Literal;
     params: [ Expression ];
     hash: Hash;
 
@@ -296,21 +324,43 @@ The `Handlebars.JavaScriptCompiler` object has a number of methods that may be c
 - `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 = Object.create(Handlebars.JavaScriptCompiler);
+MyCompiler.prototype = new Handlebars.JavaScriptCompiler();
 
-MyCompiler.nameLookup = function(parent, name, type) {
-  if (type === 'partial') {
-    return 'MyPartialList[' + JSON.stringify(name) ']';
+// 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;
-env.compile('my template');
+
+var template = env.compile('{{#each Test}} ({{Value}}) {{/each}}');
+console.log(template({
+  test: [ 
+    {value: 'a'},
+    {value: 'b'},
+    {value: 'c'}
+    ]
+}));
 ```

docs/decorators-api.md

@@ -2,9 +2,9 @@
 
 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 setup 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 syntaxs are derivitives of the normal mustache syntax and as such have all of the same argument and whitespace behaviors.
+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)`
+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`.

integration-testing/README.md

@@ -0,0 +1,12 @@
+Add a new integration test by creating a new subfolder
+
+Add a file "test.sh" to that runs the test. "test.sh" should exit with a non-zero exit code 
+and display an error message, if something goes wrong.
+
+* An integration test should reflect real-world setups that use handlebars.
+* It should compile a minimal template and compare the output to an expected output.
+* It should use "../.." as dependency for Handlebars so that the currently built library is used.
+
+Currently, integration tests are only running on Linux, especially in travis-ci.
+
+  

integration-testing/multi-nodejs-test/.eslintrc.js

@@ -0,0 +1,13 @@
+module.exports = {
+  extends: ['eslint:recommended', 'plugin:es5/no-es2015', 'prettier'],
+  globals: {
+    self: false
+  },
+  env: {
+    node: true
+  },
+  rules: {
+    'no-console': 'off',
+    'no-var': 'off'
+  }
+};

integration-testing/multi-nodejs-test/.gitignore

@@ -0,0 +1,2 @@
+target
+package-lock.json

integration-testing/multi-nodejs-test/package.json

@@ -0,0 +1,16 @@
+{
+  "name": "multi-nodejs-test",
+  "version": "1.0.0",
+  "description": "Simple integration test with all relevant NodeJS-versions.",
+  "keywords": [],
+  "author": "Nils Knappmeier",
+  "private": true,
+  "license": "MIT",
+  "dependencies": {
+    "handlebars": "file:../.."
+  },
+  "scripts": {
+    "test": "node run-handlebars.js",
+    "test-precompile": "handlebars precompile-test-template.txt.hbs"
+  }
+}

integration-testing/multi-nodejs-test/precompile-test-template.txt.hbs

@@ -0,0 +1 @@
+Author: {{author}}

integration-testing/multi-nodejs-test/run-handlebars.js

@@ -0,0 +1,11 @@
+// This test should run successfully with node 0.10++ as long as Handlebars has been compiled before
+var assert = require('assert');
+var Handlebars = require('handlebars');
+
+console.log('Testing built Handlebars with Node version ' + process.version);
+
+var template = Handlebars.compile('Author: {{author}}');
+var output = template({ author: 'Yehuda' });
+assert.strictEqual(output, 'Author: Yehuda');
+
+console.log('Success');

integration-testing/multi-nodejs-test/test.sh

@@ -0,0 +1,29 @@
+#!/bin/bash
+
+set -e
+
+cd "$( dirname "$( readlink -f "$0" )" )" || exit 1
+# shellcheck disable=SC1090
+[ -s "$NVM_DIR/nvm.sh" ] && \. "$NVM_DIR/nvm.sh"
+
+# This script tests with precompiler and the built distribution with multiple NodeJS version.
+# The rest of the travis-build will only work with newer NodeJS versions, because the build
+# tools don't support older versions.
+# However, the built distribution should work with older NodeJS versions as well.
+# This test is simple by design. It merely ensures, that calling Handlebars does not fail with old versions.
+# It does (almost) not test for correctness, because that is already done in the mocha-tests.
+# And it does not use any NodeJS based testing framwork to make this part independent of the Node version.
+
+unset npm_config_prefix
+
+echo "Handlebars should be able to run in various versions of NodeJS"
+for i in  0.10 0.12 4 5 6 7 8 9 10 11 12 13 ; do
+    rm target node_modules package-lock.json -rf
+    mkdir target
+    nvm install "$i"
+    nvm exec "$i" npm install
+    nvm exec "$i" npm run test
+    nvm exec "$i" npm run test-precompile
+
+    echo Success
+done

integration-testing/run-integration-tests.sh

@@ -0,0 +1,15 @@
+#!/bin/bash
+
+set -e
+
+cd "$( dirname "$( readlink -f "$0" )" )"
+
+for i in */test.sh ; do
+  (
+    echo "----------------------------------------"
+    echo "-- Running integration test: $i"
+    echo "----------------------------------------"
+    cd "$( dirname "$i" )"
+    ./test.sh
+  )
+done

integration-testing/webpack-babel-test/.babelrc

@@ -0,0 +1,11 @@
+{
+  "plugins": [
+    "@roundingwellos/babel-plugin-handlebars-inline-precompile"
+   // "istanbul"
+  ],
+  "presets": [
+    [
+      "@babel/preset-env"
+    ]
+  ]
+}

integration-testing/webpack-babel-test/.gitignore

@@ -0,0 +1,3 @@
+node_modules
+dist
+package-lock.json

integration-testing/webpack-babel-test/package.json

@@ -0,0 +1,24 @@
+{
+  "name": "webpack-babel-test",
+  "version": "1.0.0",
+  "description": "",
+  "main": "index.js",
+  "keywords": [],
+  "author": "",
+  "license": "ISC",
+  "dependencies": {
+    "@babel/core": "^7.5.5",
+    "@babel/preset-env": "^7.5.5",
+    "@roundingwellos/babel-plugin-handlebars-inline-precompile": "^3.0.1",
+    "babel-loader": "^8.0.6",
+    "babel-plugin-istanbul": "^5.2.0",
+    "handlebars": "file:../..",
+    "handlebars-loader": "^1.7.1",
+    "nyc": "^14.1.1",
+    "webpack": "^4.39.3",
+    "webpack-cli": "^3.3.7"
+  },
+  "scripts": {
+    "build": "webpack --config webpack.config.js"
+  }
+}

integration-testing/webpack-babel-test/src/handlebars-inline-precompile-test.js

@@ -0,0 +1,12 @@
+import * as Handlebars from 'handlebars/runtime';
+import hbs from 'handlebars-inline-precompile';
+import { assertEquals } from '../../webpack-test/src/lib/assert';
+
+Handlebars.registerHelper('loud', function(text) {
+  return text.toUpperCase();
+});
+
+const template = hbs`{{loud name}}`;
+const output = template({ name: 'yehuda' });
+
+assertEquals(output, 'YEHUDA');

integration-testing/webpack-babel-test/src/lib/assert.js

@@ -0,0 +1,5 @@
+export function assertEquals(actual, expected) {
+  if (actual !== expected) {
+    throw new Error(`Expected "${actual}" to equal "${expected}"`);
+  }
+}

integration-testing/webpack-babel-test/test.sh

@@ -0,0 +1,16 @@
+#!/bin/bash
+
+set -e
+
+# Cleanup: package-lock and "npm ci" is not working with local dependencies
+rm dist package-lock.json -rf
+npm install
+npm run build
+
+for i in dist/*-test.js ; do
+  echo "----------------------"
+  echo "-- Running $i"
+  echo "----------------------"
+  node "$i"
+  echo "Success"
+done

integration-testing/webpack-babel-test/webpack.config.js

@@ -0,0 +1,32 @@
+const fs = require('fs');
+
+const testFiles = fs.readdirSync('src');
+const entryPoints = {};
+testFiles
+  .filter(file => file.match(/-test.js$/))
+  .forEach(file => {
+    entryPoints[file] = `./src/${file}`;
+  });
+
+module.exports = {
+  entry: entryPoints,
+  output: {
+    filename: '[name]',
+    path: __dirname + '/dist'
+  },
+  module: {
+    rules: [
+      {
+        test: /\.js?$/,
+        exclude: /node_modules/,
+        use: {
+          loader: 'babel-loader',
+          options: { cacheDirectory: false }
+        }
+      }
+    ]
+  },
+  optimization: {
+    minimize: false
+  }
+};

integration-testing/webpack-test/.gitignore

@@ -0,0 +1,3 @@
+node_modules
+dist
+package-lock.json

integration-testing/webpack-test/package.json

@@ -0,0 +1,21 @@
+{
+  "name": "webpack-test",
+  "description": "Various tests with Handlebars and Webpack",
+  "version": "1.0.0",
+  "main": "index.js",
+  "scripts": {
+    "build": "webpack --config webpack.config.js",
+    "test": "node dist/main.js"
+  },
+  "private": true,
+  "keywords": [],
+  "author": "",
+  "license": "ISC",
+  "dependencies": {},
+  "devDependencies": {
+    "handlebars": "file:../..",
+    "handlebars-loader": "^1.7.1",
+    "webpack": "^4.39.3",
+    "webpack-cli": "^3.3.7"
+  }
+}

integration-testing/webpack-test/src/handlebars-default-import-pre-4.2-test.js

@@ -0,0 +1,6 @@
+import Handlebars from 'handlebars/dist/handlebars';
+
+import { assertEquals } from './lib/assert';
+
+const template = Handlebars.compile('Author: {{author}}');
+assertEquals(template({ author: 'Yehuda' }), 'Author: Yehuda');

integration-testing/webpack-test/src/handlebars-default-import-test.js

@@ -0,0 +1,5 @@
+import Handlebars from 'handlebars';
+import { assertEquals } from './lib/assert';
+
+const template = Handlebars.compile('Author: {{author}}');
+assertEquals(template({ author: 'Yehuda' }), 'Author: Yehuda');

integration-testing/webpack-test/src/handlebars-loader-test.js

@@ -0,0 +1,10 @@
+import { assertEquals } from './lib/assert';
+
+import testTemplate from './test-template.handlebars';
+assertEquals(testTemplate({ author: 'Yehuda' }).trim(), 'Author: Yehuda');
+
+const testTemplateRequire = require('./test-template.handlebars');
+assertEquals(
+  testTemplateRequire({ author: 'Yehuda' }).trim(),
+  'Author: Yehuda'
+);

integration-testing/webpack-test/src/handlebars-require-vs-import-test.js

@@ -0,0 +1,10 @@
+import * as HandlebarsViaImport from 'handlebars';
+const HandlebarsViaRequire = require('handlebars');
+import { assertEquals } from './lib/assert';
+
+HandlebarsViaImport.registerHelper('loud', function(text) {
+  return text.toUpperCase();
+});
+
+const template = HandlebarsViaRequire.compile('Author: {{loud author}}');
+assertEquals(template({ author: 'Yehuda' }), 'Author: YEHUDA');

integration-testing/webpack-test/src/handlebars-wildcard-import-pre-4.2-test.js

@@ -0,0 +1,6 @@
+import * as Handlebars from 'handlebars/dist/handlebars';
+
+import { assertEquals } from './lib/assert';
+
+const template = Handlebars.compile('Author: {{author}}');
+assertEquals(template({ author: 'Yehuda' }), 'Author: Yehuda');

integration-testing/webpack-test/src/handlebars-wildcard-import-test.js

@@ -0,0 +1,5 @@
+import * as Handlebars from 'handlebars';
+import { assertEquals } from './lib/assert';
+
+const template = Handlebars.compile('Author: {{author}}');
+assertEquals(template({ author: 'Yehuda' }), 'Author: Yehuda');

integration-testing/webpack-test/src/lib/assert.js

@@ -0,0 +1,5 @@
+export function assertEquals(actual, expected) {
+  if (actual !== expected) {
+    throw new Error(`Expected "${actual}" to equal "${expected}"`);
+  }
+}

integration-testing/webpack-test/src/test-template.handlebars

@@ -0,0 +1,2 @@
+Author: {{author}}
+

integration-testing/webpack-test/test.sh

@@ -0,0 +1,16 @@
+#!/bin/bash
+
+set -e
+
+# Cleanup: package-lock and "npm ci" is not working with local dependencies
+rm dist package-lock.json -rf
+npm install
+npm run build
+
+for i in dist/*-test.js ; do
+  echo "----------------------"
+  echo "-- Running $i"
+  echo "----------------------"
+  node "$i"
+  echo "Success"
+done

integration-testing/webpack-test/webpack.config.js

@@ -0,0 +1,20 @@
+const fs = require('fs');
+
+const testFiles = fs.readdirSync('src');
+const entryPoints = {};
+testFiles
+  .filter(file => file.match(/-test.js$/))
+  .forEach(file => {
+    entryPoints[file] = `./src/${file}`;
+  });
+
+module.exports = {
+  entry: entryPoints,
+  output: {
+    filename: '[name]',
+    path: __dirname + '/dist'
+  },
+  module: {
+    rules: [{ test: /\.handlebars$/, loader: 'handlebars-loader' }]
+  }
+};

karma-setup/.eslintrc

@@ -0,0 +1,56 @@
+{
+  "extends": [
+    "../.eslintrc.js"
+  ],
+  "overrides": [
+    {
+      "extends": [
+        "plugin:es5/no-es2015",
+        "prettier"
+      ],
+      "files": ["**/*.browser.js"],
+      "plugins": [
+        "es5"
+      ],
+      "globals": {
+        "TODO: clean this up": true,
+        "CompilerContext": true,
+        "Handlebars": true,
+        "handlebarsEnv": true,
+        "shouldCompileTo": true,
+        "shouldCompileToWithPartials": true,
+        "shouldThrow": true,
+        "expectTemplate": true,
+        "compileWithPartials": true,
+        "console": true,
+        "require": true,
+        "suite": true,
+        "equal": true,
+        "equals": true,
+        "test": true,
+        "testBoth": true,
+        "raises": true,
+        "deepEqual": true,
+        "start": true,
+        "stop": true,
+        "ok": true,
+        "sinon": true,
+        "strictEqual": true,
+        "define": true,
+        "expect": true,
+        "chai": true
+      },
+      "env": {
+        "mocha": true
+      },
+      "rules": {
+        // Disabling for tests, for now.
+        "no-path-concat": "off",
+
+        "no-var": "off",
+        "dot-notation": "off"
+      }
+    },
+  ]
+
+}

karma-setup/amd/karma.conf.js

@@ -0,0 +1,19 @@
+module.exports = function(config) {
+  config.set({
+    basePath: '../..',
+    reporters: ['dots'],
+    frameworks: ['mocha', 'requirejs'],
+    browsers: ['Chrome'],
+    files: [
+      { pattern: 'node_modules/sinon/pkg/sinon.js', included: false },
+      { pattern: 'node_modules/chai/chai.js', included: false },
+      { pattern: 'node_modules/dirty-chai/lib/dirty-chai.js', included: false },
+      { pattern: 'dist/handlebars.amd.js', included: false },
+      'karma-setup/shared/*.browser.js',
+      'karma-setup/amd/*.browser.js',
+      'spec/vendor/json2.js',
+      'spec/env/common.js',
+      { pattern: 'spec/*.js', included: false }
+    ]
+  });
+};

karma-setup/amd/require-config.browser.js

@@ -0,0 +1,38 @@
+/* global requirejs */
+
+var tests = Object.keys(window.__karma__.files).filter(function(file) {
+  return file.match(/^\/base\/spec\/[^/]*\.js/);
+});
+
+requirejs.config({
+  // Karma serves files from '/base'
+  baseUrl: '/base',
+
+  paths: {
+    handlebars: 'dist/handlebars.amd',
+    sinon: 'node_modules/sinon/pkg/sinon',
+    chai: 'node_modules/chai/chai',
+    dirtyChai: 'node_modules/dirty-chai/lib/dirty-chai'
+  },
+
+  // start test run, once Require.js is done
+  callback: function() {
+    require(['handlebars', 'chai', 'dirtyChai', 'sinon'], function(
+      Handlebars,
+      chai,
+      dirtyChai,
+      sinon
+    ) {
+      window.Handlebars = Handlebars;
+
+      chai.use(dirtyChai);
+      window.expect = chai.expect;
+
+      window.sinon = sinon;
+
+      require(tests, function() {
+        window.__karma__.start();
+      });
+    });
+  }
+});

karma-setup/default/global-expect.browser.js

@@ -0,0 +1 @@
+window.expect = chai.expect;

karma-setup/default/karma.conf.js

@@ -0,0 +1,20 @@
+module.exports = function(config) {
+  config.set({
+    basePath: '../..',
+    reporters: ['dots'],
+    frameworks: ['mocha'],
+    browsers: ['Chrome'],
+    files: [
+      'node_modules/sinon/pkg/sinon.js',
+      'node_modules/chai/chai.js',
+      'node_modules/dirty-chai/lib/dirty-chai.js',
+      'karma-setup/shared/*.browser.js',
+      'karma-setup/default/*.browser.js',
+      'spec/vendor/json2.js',
+      'spec/env/common.js',
+
+      'dist/handlebars.js',
+      'spec/*.js'
+    ]
+  });
+};

karma-setup/shared/global-compiler-context.browser.js

@@ -0,0 +1,22 @@
+window.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;
+    // eslint-disable-next-line no-eval
+    eval('ret = ' + templateSpec);
+    return ret;
+  } catch (err) {
+    // eslint-disable-next-line no-console
+    console.error(templateSpec);
+    throw err;
+  }
+}

karma-setup/shared/saucelabs.js

@@ -0,0 +1,47 @@
+// Example set of browsers to run on Sauce Labs
+// Check out https://saucelabs.com/platforms for all browser/platform combos
+const customLaunchers = {
+  sl_chrome: {
+    base: 'SauceLabs',
+    browserName: 'chrome'
+  },
+  sl_firefox: {
+    base: 'SauceLabs',
+    browserName: 'firefox',
+    platform: 'Linux'
+  },
+  sl_safari_9: {
+    base: 'SauceLabs',
+    browserName: 'safari',
+    version: 9,
+    platform: 'OS X 10.11'
+  },
+  sl_safari_8: {
+    base: 'SauceLabs',
+    browserName: 'safari',
+    version: 8,
+    platform: 'OS X 10.10'
+  },
+  sl_ie_10: {
+    base: 'SauceLabs',
+    browserName: 'internet explorer',
+    version: 10,
+    platform: 'Windows 8'
+  },
+  sl_ie_11: {
+    base: 'SauceLabs',
+    browserName: 'internet explorer',
+    platform: 'Windows 8.1',
+    version: '11'
+  }
+};
+
+const browsers = Object.keys(customLaunchers);
+
+module.exports = {
+  customLaunchers,
+  browsers,
+  sauceLabs: {
+    testName: 'handlebars-unit-tests'
+  }
+};

lib/handlebars.js

@@ -2,7 +2,11 @@ import runtime from './handlebars.runtime';
 
 // Compiler imports
 import AST from './handlebars/compiler/ast';
-import { parser as Parser, parse } from './handlebars/compiler/base';
+import {
+  parser as Parser,
+  parse,
+  parseWithoutProcessing
+} from './handlebars/compiler/base';
 import { Compiler, compile, precompile } from './handlebars/compiler/compiler';
 import JavaScriptCompiler from './handlebars/compiler/javascript-compiler';
 import Visitor from './handlebars/compiler/visitor';
@@ -25,6 +29,7 @@ function create() {
   hb.JavaScriptCompiler = JavaScriptCompiler;
   hb.Parser = Parser;
   hb.parse = parse;
+  hb.parseWithoutProcessing = parseWithoutProcessing;
 
   return hb;
 }

lib/handlebars/base.js

@@ -1,11 +1,13 @@
-import {createFrame, extend, toString} from './utils';
+import { createFrame, extend, toString } from './utils';
 import Exception from './exception';
-import {registerDefaultHelpers} from './helpers';
-import {registerDefaultDecorators} from './decorators';
+import { registerDefaultHelpers } from './helpers';
+import { registerDefaultDecorators } from './decorators';
 import logger from './logger';
+import { resetLoggedProperties } from './internal/proto-access';
 
-export const VERSION = '4.0.1';
-export const COMPILER_REVISION = 7;
+export const VERSION = '4.7.6';
+export const COMPILER_REVISION = 8;
+export const LAST_COMPATIBLE_COMPILER_REVISION = 7;
 
 export const REVISION_CHANGES = {
   1: '<= 1.0.rc.2', // 1.0.rc.2 is actually rev2 but doesn't report it
@@ -14,7 +16,8 @@ export const REVISION_CHANGES = {
   4: '== 1.x.x',
   5: '== 2.0.0-alpha.x',
   6: '>= 2.0.0-beta.1',
-  7: '>= 4.0.0'
+  7: '>= 4.0.0 <4.3.0',
+  8: '>= 4.3.0'
 };
 
 const objectType = '[object Object]';
@@ -36,7 +39,9 @@ HandlebarsEnvironment.prototype = {
 
   registerHelper: function(name, fn) {
     if (toString.call(name) === objectType) {
-      if (fn) { throw new Exception('Arg not supported with multiple helpers'); }
+      if (fn) {
+        throw new Exception('Arg not supported with multiple helpers');
+      }
       extend(this.helpers, name);
     } else {
       this.helpers[name] = fn;
@@ -51,7 +56,9 @@ HandlebarsEnvironment.prototype = {
       extend(this.partials, name);
     } else {
       if (typeof partial === 'undefined') {
-        throw new Exception('Attempting to register a partial as undefined');
+        throw new Exception(
+          `Attempting to register a partial called "${name}" as undefined`
+        );
       }
       this.partials[name] = partial;
     }
@@ -62,7 +69,9 @@ HandlebarsEnvironment.prototype = {
 
   registerDecorator: function(name, fn) {
     if (toString.call(name) === objectType) {
-      if (fn) { throw new Exception('Arg not supported with multiple decorators'); }
+      if (fn) {
+        throw new Exception('Arg not supported with multiple decorators');
+      }
       extend(this.decorators, name);
     } else {
       this.decorators[name] = fn;
@@ -70,9 +79,16 @@ HandlebarsEnvironment.prototype = {
   },
   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();
   }
 };
 
 export let log = logger.log;
 
-export {createFrame, logger};
+export { createFrame, logger };

lib/handlebars/compiler/ast.js

@@ -5,24 +5,28 @@ let AST = {
     // * it is an eligible helper, and
     // * it has at least one parameter or hash segment
     helperExpression: function(node) {
-      return (node.type === 'SubExpression')
-          || ((node.type === 'MustacheStatement' || node.type === 'BlockStatement')
-            && !!((node.params && node.params.length) || node.hash));
+      return (
+        node.type === 'SubExpression' ||
+        ((node.type === 'MustacheStatement' ||
+          node.type === 'BlockStatement') &&
+          !!((node.params && node.params.length) || node.hash))
+      );
     },
 
     scopedId: function(path) {
-      return (/^\.|this\b/).test(path.original);
+      return /^\.|this\b/.test(path.original);
     },
 
     // an ID is simple if it only has one part, and that part is not
     // `..` or `this`.
     simpleId: function(path) {
-      return path.parts.length === 1 && !AST.helpers.scopedId(path) && !path.depth;
+      return (
+        path.parts.length === 1 && !AST.helpers.scopedId(path) && !path.depth
+      );
     }
   }
 };
 
-
 // Must be exported as an object rather than the root of the module as the jison lexer
 // must modify the object to operate properly.
 export default AST;

lib/handlebars/compiler/base.js

@@ -8,9 +8,11 @@ export { parser };
 let yy = {};
 extend(yy, Helpers);
 
-export function parse(input, options) {
+export function parseWithoutProcessing(input, options) {
   // Just return if an already-compiled AST was passed in.
-  if (input.type === 'Program') { return input; }
+  if (input.type === 'Program') {
+    return input;
+  }
 
   parser.yy = yy;
 
@@ -19,6 +21,14 @@ export function parse(input, options) {
     return new yy.SourceLocation(options && options.srcName, locInfo);
   };
 
-  let strip = new WhitespaceControl(options);
-  return strip.accept(parser.parse(input));
+  let ast = parser.parse(input);
+
+  return ast;
+}
+
+export function parse(input, options) {
+  let ast = parseWithoutProcessing(input, options);
+  let strip = new WhitespaceControl(options);
+
+  return strip.accept(ast);
 }

lib/handlebars/compiler/code-gen.js

@@ -1,5 +1,5 @@
 /* global define */
-import {isArray} from '../utils';
+import { isArray } from '../utils';
 
 let SourceNode;
 
@@ -38,7 +38,7 @@ if (!SourceNode) {
       this.src = chunks + this.src;
     },
     toStringWithSourceMap: function() {
-      return {code: this.toString()};
+      return { code: this.toString() };
     },
     toString: function() {
       return this.src;
@@ -46,7 +46,6 @@ if (!SourceNode) {
   };
 }
 
-
 function castChunk(chunk, codeGen, loc) {
   if (isArray(chunk)) {
     let ret = [];
@@ -62,7 +61,6 @@ function castChunk(chunk, codeGen, loc) {
   return chunk;
 }
 
-
 function CodeGen(srcFile) {
   this.srcFile = srcFile;
   this.source = [];
@@ -94,17 +92,22 @@ CodeGen.prototype = {
   },
 
   empty: function() {
-    let loc = this.currentLocation || {start: {}};
+    let loc = this.currentLocation || { start: {} };
     return new SourceNode(loc.start.line, loc.start.column, this.srcFile);
   },
-  wrap: function(chunk, loc = this.currentLocation || {start: {}}) {
+  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);
+    return new SourceNode(
+      loc.start.line,
+      loc.start.column,
+      this.srcFile,
+      chunk
+    );
   },
 
   functionCall: function(fn, type, params) {
@@ -113,26 +116,28 @@ CodeGen.prototype = {
   },
 
   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') + '"';
+    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 = [];
 
-    for (let key in obj) {
-      if (obj.hasOwnProperty(key)) {
-        let value = castChunk(obj[key], this);
-        if (value !== 'undefined') {
-          pairs.push([this.quotedString(key), ':', value]);
-        }
+    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('{');
@@ -140,7 +145,6 @@ CodeGen.prototype = {
     return ret;
   },
 
-
   generateList: function(entries) {
     let ret = this.empty();
 
@@ -165,4 +169,3 @@ CodeGen.prototype = {
 };
 
 export default CodeGen;
-

lib/handlebars/compiler/compiler.js

@@ -1,7 +1,7 @@
 /* eslint-disable new-cap */
 
 import Exception from '../exception';
-import {isArray, indexOf} from '../utils';
+import { isArray, indexOf, extend } from '../utils';
 import AST from './ast';
 
 const slice = [].slice;
@@ -24,8 +24,11 @@ Compiler.prototype = {
 
     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)) {
+        otherOpcode = other.opcodes[i];
+      if (
+        opcode.opcode !== otherOpcode.opcode ||
+        !argEquals(opcode.args, otherOpcode.args)
+      ) {
         return false;
       }
     }
@@ -54,34 +57,28 @@ Compiler.prototype = {
 
     options.blockParams = options.blockParams || [];
 
-    // These changes will propagate to the other compiler components
-    let knownHelpers = options.knownHelpers;
-    options.knownHelpers = {
-      'helperMissing': true,
-      'blockHelperMissing': true,
-      'each': true,
-      'if': true,
-      'unless': true,
-      'with': true,
-      'log': true,
-      'lookup': true
-    };
-    if (knownHelpers) {
-      for (let name in knownHelpers) {
-        /* istanbul ignore else */
-        if (name in knownHelpers) {
-          options.knownHelpers[name] = knownHelpers[name];
-        }
-      }
-    }
+    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);
   },
 
   compileProgram: function(program) {
     let childCompiler = new this.compiler(), // eslint-disable-line new-cap
-        result = childCompiler.compile(program, this.options),
-        guid = this.guid++;
+      result = childCompiler.compile(program, this.options),
+      guid = this.guid++;
 
     this.usePartial = this.usePartial || result.usePartial;
 
@@ -107,7 +104,7 @@ Compiler.prototype = {
     this.options.blockParams.unshift(program.blockParams);
 
     let body = program.body,
-        bodyLength = body.length;
+      bodyLength = body.length;
     for (let i = 0; i < bodyLength; i++) {
       this.accept(body[i]);
     }
@@ -124,7 +121,7 @@ Compiler.prototype = {
     transformLiteralToPath(block);
 
     let program = block.program,
-        inverse = block.inverse;
+      inverse = block.inverse;
 
     program = program && this.compileProgram(program);
     inverse = inverse && this.compileProgram(inverse);
@@ -159,7 +156,7 @@ Compiler.prototype = {
   DecoratorBlock(decorator) {
     let program = decorator.program && this.compileProgram(decorator.program);
     let params = this.setupFullMustacheParams(decorator, program, undefined),
-        path = decorator.path;
+      path = decorator.path;
 
     this.useDecorators = true;
     this.opcode('registerDecorator', params.length, path.original);
@@ -175,17 +172,20 @@ Compiler.prototype = {
 
     let params = partial.params;
     if (params.length > 1) {
-      throw new Exception('Unsupported number of partial arguments: ' + params.length, partial);
+      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});
+        params.push({ type: 'PathExpression', parts: [], depth: 0 });
       }
     }
 
     let partialName = partial.name.original,
-        isDynamic = partial.name.type === 'SubExpression';
+      isDynamic = partial.name.type === 'SubExpression';
     if (isDynamic) {
       this.accept(partial.name);
     }
@@ -218,7 +218,6 @@ Compiler.prototype = {
     this.DecoratorBlock(decorator);
   },
 
-
   ContentStatement: function(content) {
     if (content.value) {
       this.opcode('appendContent', content.value);
@@ -241,8 +240,8 @@ Compiler.prototype = {
   },
   ambiguousSexpr: function(sexpr, program, inverse) {
     let path = sexpr.path,
-        name = path.parts[0],
-        isBlock = program != null || inverse != null;
+      name = path.parts[0],
+      isBlock = program != null || inverse != null;
 
     this.opcode('getContext', path.depth);
 
@@ -264,19 +263,27 @@ Compiler.prototype = {
 
   helperSexpr: function(sexpr, program, inverse) {
     let params = this.setupFullMustacheParams(sexpr, program, inverse),
-        path = sexpr.path,
-        name = path.parts[0];
+      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);
+      throw new Exception(
+        'You specified knownHelpersOnly, but used the unknown helper ' + name,
+        sexpr
+      );
     } else {
       path.strict = true;
       path.falsy = true;
 
       this.accept(path);
-      this.opcode('invokeHelper', params.length, path.original, AST.helpers.simpleId(path));
+      this.opcode(
+        'invokeHelper',
+        params.length,
+        path.original,
+        AST.helpers.simpleId(path)
+      );
     }
   },
 
@@ -285,8 +292,8 @@ Compiler.prototype = {
     this.opcode('getContext', path.depth);
 
     let name = path.parts[0],
-        scoped = AST.helpers.scopedId(path),
-        blockParamId = !path.depth && !scoped && this.blockParamIndex(name);
+      scoped = AST.helpers.scopedId(path),
+      blockParamId = !path.depth && !scoped && this.blockParamIndex(name);
 
     if (blockParamId) {
       this.opcode('lookupBlockParam', blockParamId, path.parts);
@@ -297,7 +304,13 @@ Compiler.prototype = {
       this.options.data = true;
       this.opcode('lookupData', path.depth, path.parts, path.strict);
     } else {
-      this.opcode('lookupOnContext', path.parts, path.falsy, path.strict, scoped);
+      this.opcode(
+        'lookupOnContext',
+        path.parts,
+        path.falsy,
+        path.strict,
+        scoped
+      );
     }
   },
 
@@ -323,8 +336,8 @@ Compiler.prototype = {
 
   Hash: function(hash) {
     let pairs = hash.pairs,
-        i = 0,
-        l = pairs.length;
+      i = 0,
+      l = pairs.length;
 
     this.opcode('pushHash');
 
@@ -339,7 +352,11 @@ Compiler.prototype = {
 
   // HELPERS
   opcode: function(name) {
-    this.opcodes.push({ opcode: name, args: slice.call(arguments, 1), loc: this.sourceNode[0].loc });
+    this.opcodes.push({
+      opcode: name,
+      args: slice.call(arguments, 1),
+      loc: this.sourceNode[0].loc
+    });
   },
 
   addDepth: function(depth) {
@@ -368,8 +385,7 @@ Compiler.prototype = {
     // An eligible helper is one that does not have a complex path, i.e. `this.foo`, `../foo` etc.
     if (isEligible && !isHelper) {
       let name = sexpr.path.parts[0],
-          options = this.options;
-
+        options = this.options;
       if (options.knownHelpers[name]) {
         isHelper = true;
       } else if (options.knownHelpersOnly) {
@@ -397,9 +413,7 @@ Compiler.prototype = {
 
     if (this.stringParams) {
       if (value.replace) {
-        value = value
-            .replace(/^(\.?\.\/)*/g, '')
-            .replace(/\//g, '.');
+        value = value.replace(/^(\.?\.\/)*/g, '').replace(/\//g, '.');
       }
 
       if (val.depth) {
@@ -417,7 +431,7 @@ Compiler.prototype = {
       if (this.trackIds) {
         let blockParamIndex;
         if (val.parts && !AST.helpers.scopedId(val) && !val.depth) {
-           blockParamIndex = this.blockParamIndex(val.parts[0]);
+          blockParamIndex = this.blockParamIndex(val.parts[0]);
         }
         if (blockParamIndex) {
           let blockParamChild = val.parts.slice(1).join('.');
@@ -426,9 +440,9 @@ Compiler.prototype = {
           value = val.original || value;
           if (value.replace) {
             value = value
-                .replace(/^this(?:\.|$)/, '')
-                .replace(/^\.\//, '')
-                .replace(/^\.$/, '');
+              .replace(/^this(?:\.|$)/, '')
+              .replace(/^\.\//, '')
+              .replace(/^\.$/, '');
           }
 
           this.opcode('pushId', val.type, value);
@@ -455,9 +469,13 @@ Compiler.prototype = {
   },
 
   blockParamIndex: function(name) {
-    for (let depth = 0, len = this.options.blockParams.length; depth < len; depth++) {
+    for (
+      let depth = 0, len = this.options.blockParams.length;
+      depth < len;
+      depth++
+    ) {
       let blockParams = this.options.blockParams[depth],
-          param = blockParams && indexOf(blockParams, name);
+        param = blockParams && indexOf(blockParams, name);
       if (blockParams && param >= 0) {
         return [depth, param];
       }
@@ -466,8 +484,14 @@ Compiler.prototype = {
 };
 
 export function precompile(input, options, env) {
-  if (input == null || (typeof input !== 'string' && input.type !== 'Program')) {
-    throw new Exception('You must pass a string or Handlebars AST to Handlebars.precompile. You passed ' + input);
+  if (
+    input == null ||
+    (typeof input !== 'string' && input.type !== 'Program')
+  ) {
+    throw new Exception(
+      'You must pass a string or Handlebars AST to Handlebars.precompile. You passed ' +
+        input
+    );
   }
 
   options = options || {};
@@ -479,15 +503,22 @@ export function precompile(input, options, env) {
   }
 
   let ast = env.parse(input, options),
-      environment = new env.Compiler().compile(ast, options);
+    environment = new env.Compiler().compile(ast, options);
   return new env.JavaScriptCompiler().compile(environment, options);
 }
 
 export function compile(input, options = {}, env) {
-  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 (
+    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
+    );
   }
 
+  options = extend({}, options);
   if (!('data' in options)) {
     options.data = true;
   }
@@ -499,8 +530,13 @@ export function compile(input, options = {}, env) {
 
   function compileInput() {
     let ast = env.parse(input, options),
-        environment = new env.Compiler().compile(ast, options),
-        templateSpec = new env.JavaScriptCompiler().compile(environment, options, undefined, true);
+      environment = new env.Compiler().compile(ast, options),
+      templateSpec = new env.JavaScriptCompiler().compile(
+        environment,
+        options,
+        undefined,
+        true
+      );
     return env.template(templateSpec);
   }
 

lib/handlebars/compiler/helpers.js

@@ -4,9 +4,12 @@ function validateClose(open, close) {
   close = close.path ? close.path.original : close;
 
   if (open.path.original !== close) {
-    let errorNode = {loc: open.path.loc};
+    let errorNode = { loc: open.path.loc };
 
-    throw new Exception(open.path.original + " doesn't match " + close, errorNode);
+    throw new Exception(
+      open.path.original + " doesn't match " + close,
+      errorNode
+    );
   }
 }
 
@@ -24,7 +27,7 @@ export function SourceLocation(source, locInfo) {
 
 export function id(token) {
   if (/^\[.*\]$/.test(token)) {
-    return token.substr(1, token.length - 2);
+    return token.substring(1, token.length - 1);
   } else {
     return token;
   }
@@ -38,31 +41,28 @@ export function stripFlags(open, close) {
 }
 
 export function stripComment(comment) {
-  return comment.replace(/^\{\{~?\!-?-?/, '')
-                .replace(/-?-?~?\}\}$/, '');
+  return comment.replace(/^\{\{~?!-?-?/, '').replace(/-?-?~?\}\}$/, '');
 }
 
 export function preparePath(data, parts, loc) {
   loc = this.locInfo(loc);
 
   let original = data ? '@' : '',
-      dig = [],
-      depth = 0,
-      depthString = '';
+    dig = [],
+    depth = 0;
 
   for (let i = 0, l = parts.length; i < l; i++) {
     let part = parts[i].part,
-        // If we have [] syntax then we do not treat path references as operators,
-        // i.e. foo.[this] resolves to approximately context.foo['this']
-        isLiteral = parts[i].original !== part;
+      // If we have [] syntax then we do not treat path references as operators,
+      // i.e. foo.[this] resolves to approximately context.foo['this']
+      isLiteral = parts[i].original !== part;
     original += (parts[i].separator || '') + part;
 
     if (!isLiteral && (part === '..' || part === '.' || part === 'this')) {
       if (dig.length > 0) {
-        throw new Exception('Invalid path: ' + original, {loc});
+        throw new Exception('Invalid path: ' + original, { loc });
       } else if (part === '..') {
         depth++;
-        depthString += '../';
       }
     } else {
       dig.push(part);
@@ -82,9 +82,9 @@ export function preparePath(data, parts, loc) {
 export function prepareMustache(path, params, hash, open, strip, locInfo) {
   // Must use charAt to support IE pre-10
   let escapeFlag = open.charAt(3) || open.charAt(2),
-      escaped = escapeFlag !== '{' && escapeFlag !== '&';
+    escaped = escapeFlag !== '{' && escapeFlag !== '&';
 
-  let decorator = (/\*/.test(open));
+  let decorator = /\*/.test(open);
   return {
     type: decorator ? 'Decorator' : 'MustacheStatement',
     path,
@@ -120,21 +120,30 @@ export function prepareRawBlock(openRawBlock, contents, close, locInfo) {
   };
 }
 
-export function prepareBlock(openBlock, program, inverseAndProgram, close, inverted, locInfo) {
+export function prepareBlock(
+  openBlock,
+  program,
+  inverseAndProgram,
+  close,
+  inverted,
+  locInfo
+) {
   if (close && close.path) {
     validateClose(openBlock, close);
   }
 
-  let decorator = (/\*/.test(openBlock.open));
+  let decorator = /\*/.test(openBlock.open);
 
   program.blockParams = openBlock.blockParams;
 
-  let inverse,
-      inverseStrip;
+  let inverse, inverseStrip;
 
   if (inverseAndProgram) {
     if (decorator) {
-      throw new Exception('Unexpected inverse block on decorator', inverseAndProgram);
+      throw new Exception(
+        'Unexpected inverse block on decorator',
+        inverseAndProgram
+      );
     }
 
     if (inverseAndProgram.chain) {
@@ -168,7 +177,7 @@ export function prepareBlock(openBlock, program, inverseAndProgram, close, inver
 export function prepareProgram(statements, loc) {
   if (!loc && statements.length) {
     const firstLoc = statements[0].loc,
-          lastLoc = statements[statements.length - 1].loc;
+      lastLoc = statements[statements.length - 1].loc;
 
     /* istanbul ignore else */
     if (firstLoc && lastLoc) {
@@ -194,7 +203,6 @@ export function prepareProgram(statements, loc) {
   };
 }
 
-
 export function preparePartialBlock(open, program, close, locInfo) {
   validateClose(open, close);
 
@@ -209,4 +217,3 @@ export function preparePartialBlock(open, program, close, locInfo) {
     loc: this.locInfo(locInfo)
   };
 }
-

lib/handlebars/compiler/javascript-compiler.js

@@ -1,6 +1,6 @@
 import { COMPILER_REVISION, REVISION_CHANGES } from '../base';
 import Exception from '../exception';
-import {isArray} from '../utils';
+import { isArray } from '../utils';
 import CodeGen from './code-gen';
 
 function Literal(value) {
@@ -12,12 +12,8 @@ function JavaScriptCompiler() {}
 JavaScriptCompiler.prototype = {
   // PUBLIC API: You can override these methods in a subclass to provide
   // alternative compiled forms for name lookup and buffering semantics
-  nameLookup: function(parent, name /* , type*/) {
-    if (JavaScriptCompiler.isValidJavaScriptVariableName(name)) {
-      return [parent, '.', name];
-    } else {
-      return [parent, '[', JSON.stringify(name), ']'];
-    }
+  nameLookup: function(parent, name /*,  type */) {
+    return this.internalNameLookup(parent, name);
   },
   depthedLookup: function(name) {
     return [this.aliasable('container.lookup'), '(depths, "', name, '")'];
@@ -25,7 +21,7 @@ JavaScriptCompiler.prototype = {
 
   compilerInfo: function() {
     const revision = COMPILER_REVISION,
-          versions = REVISION_CHANGES[revision];
+      versions = REVISION_CHANGES[revision];
     return [revision, versions];
   },
 
@@ -53,6 +49,12 @@ JavaScriptCompiler.prototype = {
     return this.quotedString('');
   },
   // END PUBLIC API
+  internalNameLookup: function(parent, name) {
+    this.lookupPropertyFunctionIsUsed = true;
+    return ['lookupProperty(', parent, ',', JSON.stringify(name), ')'];
+  },
+
+  lookupPropertyFunctionIsUsed: false,
 
   compile: function(environment, options, context, asObject) {
     this.environment = environment;
@@ -82,14 +84,18 @@ JavaScriptCompiler.prototype = {
 
     this.compileChildren(environment, options);
 
-    this.useDepths = this.useDepths || environment.useDepths || environment.useDecorators || this.options.compat;
+    this.useDepths =
+      this.useDepths ||
+      environment.useDepths ||
+      environment.useDecorators ||
+      this.options.compat;
     this.useBlockParams = this.useBlockParams || environment.useBlockParams;
 
     let opcodes = environment.opcodes,
-        opcode,
-        firstLoc,
-        i,
-        l;
+      opcode,
+      firstLoc,
+      i,
+      l;
 
     for (i = 0, l = opcodes.length; i < l; i++) {
       opcode = opcodes[i];
@@ -111,13 +117,28 @@ JavaScriptCompiler.prototype = {
     if (!this.decorators.isEmpty()) {
       this.useDecorators = true;
 
-      this.decorators.prepend('var decorators = container.decorators;\n');
+      this.decorators.prepend([
+        'var decorators = container.decorators, ',
+        this.lookupPropertyFunctionVarDeclaration(),
+        ';\n'
+      ]);
       this.decorators.push('return fn;');
 
       if (asObject) {
-        this.decorators = Function.apply(this, ['fn', 'props', 'container', 'depth0', 'data', 'blockParams', 'depths', this.decorators.merge()]);
+        this.decorators = Function.apply(this, [
+          'fn',
+          'props',
+          'container',
+          'depth0',
+          'data',
+          'blockParams',
+          'depths',
+          this.decorators.merge()
+        ]);
       } else {
-        this.decorators.prepend('function(fn, props, container, depth0, data, blockParams, depths) {\n');
+        this.decorators.prepend(
+          'function(fn, props, container, depth0, data, blockParams, depths) {\n'
+        );
         this.decorators.push('}\n');
         this.decorators = this.decorators.merge();
       }
@@ -133,11 +154,11 @@ JavaScriptCompiler.prototype = {
       };
 
       if (this.decorators) {
-        ret.main_d = this.decorators;   // eslint-disable-line camelcase
+        ret.main_d = this.decorators; // eslint-disable-line camelcase
         ret.useDecorators = true;
       }
 
-      let {programs, decorators} = this.context;
+      let { programs, decorators } = this.context;
       for (i = 0, l = programs.length; i < l; i++) {
         if (programs[i]) {
           ret[i] = programs[i];
@@ -167,11 +188,11 @@ JavaScriptCompiler.prototype = {
       if (!asObject) {
         ret.compiler = JSON.stringify(ret.compiler);
 
-        this.source.currentLocation = {start: {line: 1, column: 0}};
+        this.source.currentLocation = { start: { line: 1, column: 0 } };
         ret = this.objectLiteral(ret);
 
         if (options.srcName) {
-          ret = ret.toStringWithSourceMap({file: options.destName});
+          ret = ret.toStringWithSourceMap({ file: options.destName });
           ret.map = ret.map && ret.map.toString();
         } else {
           ret = ret.toString();
@@ -209,13 +230,16 @@ JavaScriptCompiler.prototype = {
     // aliases will not be used, but this case is already being run on the client and
     // we aren't concern about minimizing the template size.
     let aliasCount = 0;
-    for (let alias in this.aliases) {    // eslint-disable-line guard-for-in
+    Object.keys(this.aliases).forEach(alias => {
       let node = this.aliases[alias];
-
-      if (this.aliases.hasOwnProperty(alias) && node.children && node.referenceCount > 1) {
-        varDeclarations += ', alias' + (++aliasCount) + '=' + alias;
+      if (node.children && node.referenceCount > 1) {
+        varDeclarations += ', alias' + ++aliasCount + '=' + alias;
         node.children[0] = 'alias' + aliasCount;
       }
+    });
+
+    if (this.lookupPropertyFunctionIsUsed) {
+      varDeclarations += ', ' + this.lookupPropertyFunctionVarDeclaration();
     }
 
     let params = ['container', 'depth0', 'helpers', 'partials', 'data'];
@@ -235,18 +259,23 @@ JavaScriptCompiler.prototype = {
 
       return Function.apply(this, params);
     } else {
-      return this.source.wrap(['function(', params.join(','), ') {\n  ', source, '}']);
+      return this.source.wrap([
+        'function(',
+        params.join(','),
+        ') {\n  ',
+        source,
+        '}'
+      ]);
     }
   },
   mergeSource: function(varDeclarations) {
     let isSimple = this.environment.isSimple,
-        appendOnly = !this.forceBuffer,
-        appendFirst,
-
-        sourceSeen,
-        bufferStart,
-        bufferEnd;
-    this.source.each((line) => {
+      appendOnly = !this.forceBuffer,
+      appendFirst,
+      sourceSeen,
+      bufferStart,
+      bufferEnd;
+    this.source.each(line => {
       if (line.appendToBuffer) {
         if (bufferStart) {
           line.prepend('  + ');
@@ -272,7 +301,6 @@ JavaScriptCompiler.prototype = {
       }
     });
 
-
     if (appendOnly) {
       if (bufferStart) {
         bufferStart.prepend('return ');
@@ -281,7 +309,8 @@ JavaScriptCompiler.prototype = {
         this.source.push('return "";');
       }
     } else {
-      varDeclarations += ', buffer = ' + (appendFirst ? '' : this.initializeBuffer());
+      varDeclarations +=
+        ', buffer = ' + (appendFirst ? '' : this.initializeBuffer());
 
       if (bufferStart) {
         bufferStart.prepend('return buffer + ');
@@ -292,12 +321,25 @@ JavaScriptCompiler.prototype = {
     }
 
     if (varDeclarations) {
-      this.source.prepend('var ' + varDeclarations.substring(2) + (appendFirst ? '' : ';\n'));
+      this.source.prepend(
+        'var ' + varDeclarations.substring(2) + (appendFirst ? '' : ';\n')
+      );
     }
 
     return this.source.merge();
   },
 
+  lookupPropertyFunctionVarDeclaration: function() {
+    return `
+      lookupProperty = container.lookupProperty || function(parent, propertyName) {
+        if (Object.prototype.hasOwnProperty.call(parent, propertyName)) {
+          return parent[propertyName];
+        }
+        return undefined
+    }
+    `.trim();
+  },
+
   // [blockValue]
   //
   // On stack, before: hash, inverse, program, value
@@ -308,8 +350,10 @@ JavaScriptCompiler.prototype = {
   // replace it on the stack with the result of properly
   // invoking blockHelperMissing.
   blockValue: function(name) {
-    let blockHelperMissing = this.aliasable('helpers.blockHelperMissing'),
-        params = [this.contextName(0)];
+    let blockHelperMissing = this.aliasable(
+        'container.hooks.blockHelperMissing'
+      ),
+      params = [this.contextName(0)];
     this.setupHelperArgs(name, 0, params);
 
     let blockName = this.popStack();
@@ -326,8 +370,10 @@ JavaScriptCompiler.prototype = {
   // On stack, after, if lastHelper: value
   ambiguousBlockValue: function() {
     // We're being a bit cheeky and reusing the options value from the prior exec
-    let blockHelperMissing = this.aliasable('helpers.blockHelperMissing'),
-        params = [this.contextName(0)];
+    let blockHelperMissing = this.aliasable(
+        'container.hooks.blockHelperMissing'
+      ),
+      params = [this.contextName(0)];
     this.setupHelperArgs('', 0, params, true);
 
     this.flushInline();
@@ -336,9 +382,14 @@ JavaScriptCompiler.prototype = {
     params.splice(1, 0, current);
 
     this.pushSource([
-        'if (!', this.lastHelper, ') { ',
-          current, ' = ', this.source.functionCall(blockHelperMissing, 'call', params),
-        '}']);
+      'if (!',
+      this.lastHelper,
+      ') { ',
+      current,
+      ' = ',
+      this.source.functionCall(blockHelperMissing, 'call', params),
+      '}'
+    ]);
   },
 
   // [appendContent]
@@ -368,14 +419,24 @@ JavaScriptCompiler.prototype = {
   // Otherwise, the empty string is appended
   append: function() {
     if (this.isInline()) {
-      this.replaceStack((current) => [' != null ? ', current, ' : ""']);
+      this.replaceStack(current => [' != null ? ', current, ' : ""']);
 
       this.pushSource(this.appendToBuffer(this.popStack()));
     } else {
       let local = this.popStack();
-      this.pushSource(['if (', local, ' != null) { ', this.appendToBuffer(local, undefined, true), ' }']);
+      this.pushSource([
+        'if (',
+        local,
+        ' != null) { ',
+        this.appendToBuffer(local, undefined, true),
+        ' }'
+      ]);
       if (this.environment.isSimple) {
-        this.pushSource(['else { ', this.appendToBuffer("''", undefined, true), ' }']);
+        this.pushSource([
+          'else { ',
+          this.appendToBuffer("''", undefined, true),
+          ' }'
+        ]);
       }
     }
   },
@@ -387,8 +448,14 @@ JavaScriptCompiler.prototype = {
   //
   // Escape `value` and append it to the buffer
   appendEscaped: function() {
-    this.pushSource(this.appendToBuffer(
-        [this.aliasable('container.escapeExpression'), '(', this.popStack(), ')']));
+    this.pushSource(
+      this.appendToBuffer([
+        this.aliasable('container.escapeExpression'),
+        '(',
+        this.popStack(),
+        ')'
+      ])
+    );
   },
 
   // [getContext]
@@ -472,7 +539,7 @@ JavaScriptCompiler.prototype = {
     let len = parts.length;
     for (; i < len; i++) {
       /* eslint-disable no-loop-func */
-      this.replaceStack((current) => {
+      this.replaceStack(current => {
         let lookup = this.nameLookup(current, parts[i], type);
         // We want to ensure that zero and false are handled properly if the context (falsy flag)
         // needs to have the special handling for these values.
@@ -495,7 +562,14 @@ JavaScriptCompiler.prototype = {
   // If the `value` is a lambda, replace it on the stack by
   // the return value of the lambda
   resolvePossibleLambda: function() {
-    this.push([this.aliasable('container.lambda'), '(', this.popStack(), ', ', this.contextName(0), ')']);
+    this.push([
+      this.aliasable('container.lambda'),
+      '(',
+      this.popStack(),
+      ', ',
+      this.contextName(0),
+      ')'
+    ]);
   },
 
   // [pushStringParam]
@@ -535,7 +609,7 @@ JavaScriptCompiler.prototype = {
     if (this.hash) {
       this.hashes.push(this.hash);
     }
-    this.hash = {values: [], types: [], contexts: [], ids: []};
+    this.hash = { values: {}, types: [], contexts: [], ids: [] };
   },
   popHash: function() {
     let hash = this.hash;
@@ -599,11 +673,16 @@ JavaScriptCompiler.prototype = {
   // and inserts the decorator into the decorators list.
   registerDecorator(paramSize, name) {
     let foundDecorator = this.nameLookup('decorators', name, 'decorator'),
-        options = this.setupHelperArgs(name, paramSize);
+      options = this.setupHelperArgs(name, paramSize);
 
     this.decorators.push([
       'fn = ',
-      this.decorators.functionCall(foundDecorator, '', ['fn', 'props', 'container', options]),
+      this.decorators.functionCall(foundDecorator, '', [
+        'fn',
+        'props',
+        'container',
+        options
+      ]),
       ' || fn;'
     ]);
   },
@@ -619,18 +698,43 @@ JavaScriptCompiler.prototype = {
   // If the helper is not found, `helperMissing` is called.
   invokeHelper: function(paramSize, name, isSimple) {
     let nonHelper = this.popStack(),
-        helper = this.setupHelper(paramSize, name),
-        simple = isSimple ? [helper.name, ' || '] : '';
+      helper = this.setupHelper(paramSize, name);
 
-    let lookup = ['('].concat(simple, nonHelper);
-    if (!this.options.strict) {
-      lookup.push(' || ', this.aliasable('helpers.helperMissing'));
+    let possibleFunctionCalls = [];
+
+    if (isSimple) {
+      // direct call to helper
+      possibleFunctionCalls.push(helper.name);
+    }
+    // call a function from the input object
+    possibleFunctionCalls.push(nonHelper);
+    if (!this.options.strict) {
+      possibleFunctionCalls.push(
+        this.aliasable('container.hooks.helperMissing')
+      );
     }
-    lookup.push(')');
 
-    this.push(this.source.functionCall(lookup, 'call', helper.callParams));
+    let functionLookupCode = [
+      '(',
+      this.itemsSeparatedBy(possibleFunctionCalls, '||'),
+      ')'
+    ];
+    let functionCall = this.source.functionCall(
+      functionLookupCode,
+      'call',
+      helper.callParams
+    );
+    this.push(functionCall);
   },
 
+  itemsSeparatedBy: function(items, separator) {
+    let result = [];
+    result.push(items[0]);
+    for (let i = 1; i < items.length; i++) {
+      result.push(separator, items[i]);
+    }
+    return result;
+  },
   // [invokeKnownHelper]
   //
   // On stack, before: hash, inverse, program, params..., ...
@@ -663,22 +767,31 @@ JavaScriptCompiler.prototype = {
     this.emptyHash();
     let helper = this.setupHelper(0, name, helperCall);
 
-    let helperName = this.lastHelper = this.nameLookup('helpers', name, 'helper');
+    let helperName = (this.lastHelper = this.nameLookup(
+      'helpers',
+      name,
+      'helper'
+    ));
 
     let lookup = ['(', '(helper = ', helperName, ' || ', nonHelper, ')'];
     if (!this.options.strict) {
       lookup[0] = '(helper = ';
       lookup.push(
         ' != null ? helper : ',
-        this.aliasable('helpers.helperMissing')
+        this.aliasable('container.hooks.helperMissing')
       );
     }
 
     this.push([
-        '(', lookup,
-        (helper.paramsInit ? ['),(', helper.paramsInit] : []), '),',
-        '(typeof helper === ', this.aliasable('"function"'), ' ? ',
-        this.source.functionCall('helper', 'call', helper.callParams), ' : helper))'
+      '(',
+      lookup,
+      helper.paramsInit ? ['),(', helper.paramsInit] : [],
+      '),',
+      '(typeof helper === ',
+      this.aliasable('"function"'),
+      ' ? ',
+      this.source.functionCall('helper', 'call', helper.callParams),
+      ' : helper))'
     ]);
   },
 
@@ -691,7 +804,7 @@ JavaScriptCompiler.prototype = {
   // and pushes the result of the invocation back.
   invokePartial: function(isDynamic, name, indent) {
     let params = [],
-        options = this.setupParams(name, 1, params);
+      options = this.setupParams(name, 1, params);
 
     if (isDynamic) {
       name = this.popStack();
@@ -728,9 +841,9 @@ JavaScriptCompiler.prototype = {
   // Pops a value off the stack and assigns it to the current hash
   assignToHash: function(key) {
     let value = this.popStack(),
-        context,
-        type,
-        id;
+      context,
+      type,
+      id;
 
     if (this.trackIds) {
       id = this.popStack();
@@ -756,8 +869,13 @@ JavaScriptCompiler.prototype = {
   pushId: function(type, name, child) {
     if (type === 'BlockParam') {
       this.pushStackLiteral(
-          'blockParams[' + name[0] + '].path[' + name[1] + ']'
-          + (child ? ' + ' + JSON.stringify('.' + child) : ''));
+        'blockParams[' +
+          name[0] +
+          '].path[' +
+          name[1] +
+          ']' +
+          (child ? ' + ' + JSON.stringify('.' + child) : '')
+      );
     } else if (type === 'PathExpression') {
       this.pushString(name);
     } else if (type === 'SubExpression') {
@@ -772,31 +890,40 @@ JavaScriptCompiler.prototype = {
   compiler: JavaScriptCompiler,
 
   compileChildren: function(environment, options) {
-    let children = environment.children, child, compiler;
+    let children = environment.children,
+      child,
+      compiler;
 
     for (let i = 0, l = children.length; i < l; i++) {
       child = children[i];
-      compiler = new this.compiler();    // eslint-disable-line new-cap
+      compiler = new this.compiler(); // eslint-disable-line new-cap
 
-      let index = this.matchExistingProgram(child);
+      let existing = this.matchExistingProgram(child);
 
-      if (index == null) {
-        this.context.programs.push('');     // Placeholder to prevent name conflicts for nested children
-        index = this.context.programs.length;
+      if (existing == null) {
+        this.context.programs.push(''); // Placeholder to prevent name conflicts for nested children
+        let index = this.context.programs.length;
         child.index = index;
         child.name = 'program' + index;
-        this.context.programs[index] = compiler.compile(child, options, this.context, !this.precompile);
+        this.context.programs[index] = compiler.compile(
+          child,
+          options,
+          this.context,
+          !this.precompile
+        );
         this.context.decorators[index] = compiler.decorators;
         this.context.environments[index] = child;
 
         this.useDepths = this.useDepths || compiler.useDepths;
         this.useBlockParams = this.useBlockParams || compiler.useBlockParams;
+        child.useDepths = this.useDepths;
+        child.useBlockParams = this.useBlockParams;
       } else {
-        child.index = index;
-        child.name = 'program' + index;
+        child.index = existing.index;
+        child.name = 'program' + existing.index;
 
-        this.useDepths = this.useDepths || child.useDepths;
-        this.useBlockParams = this.useBlockParams || child.useBlockParams;
+        this.useDepths = this.useDepths || existing.useDepths;
+        this.useBlockParams = this.useBlockParams || existing.useBlockParams;
       }
     }
   },
@@ -804,14 +931,14 @@ JavaScriptCompiler.prototype = {
     for (let i = 0, len = this.context.environments.length; i < len; i++) {
       let environment = this.context.environments[i];
       if (environment && environment.equals(child)) {
-        return i;
+        return environment;
       }
     }
   },
 
   programExpression: function(guid) {
     let child = this.environment.children[guid],
-        programParams = [child.index, 'data', child.blockParams];
+      programParams = [child.index, 'data', child.blockParams];
 
     if (this.useBlockParams || this.useDepths) {
       programParams.push('blockParams');
@@ -846,7 +973,11 @@ JavaScriptCompiler.prototype = {
   pushSource: function(source) {
     if (this.pendingContent) {
       this.source.push(
-          this.appendToBuffer(this.source.quotedString(this.pendingContent), this.pendingLocation));
+        this.appendToBuffer(
+          this.source.quotedString(this.pendingContent),
+          this.pendingLocation
+        )
+      );
       this.pendingContent = undefined;
     }
 
@@ -857,9 +988,9 @@ JavaScriptCompiler.prototype = {
 
   replaceStack: function(callback) {
     let prefix = ['('],
-        stack,
-        createdStack,
-        usedLiteral;
+      stack,
+      createdStack,
+      usedLiteral;
 
     /* istanbul ignore next */
     if (!this.isInline()) {
@@ -896,7 +1027,9 @@ JavaScriptCompiler.prototype = {
 
   incrStack: function() {
     this.stackSlot++;
-    if (this.stackSlot > this.stackVars.length) { this.stackVars.push('stack' + this.stackSlot); }
+    if (this.stackSlot > this.stackVars.length) {
+      this.stackVars.push('stack' + this.stackSlot);
+    }
     return this.topStackName();
   },
   topStackName: function() {
@@ -923,9 +1056,9 @@ JavaScriptCompiler.prototype = {
 
   popStack: function(wrapped) {
     let inline = this.isInline(),
-        item = (inline ? this.inlineStack : this.compileStack).pop();
+      item = (inline ? this.inlineStack : this.compileStack).pop();
 
-    if (!wrapped && (item instanceof Literal)) {
+    if (!wrapped && item instanceof Literal) {
       return item.value;
     } else {
       if (!inline) {
@@ -940,8 +1073,8 @@ JavaScriptCompiler.prototype = {
   },
 
   topStack: function() {
-    let stack = (this.isInline() ? this.inlineStack : this.compileStack),
-        item = stack[stack.length - 1];
+    let stack = this.isInline() ? this.inlineStack : this.compileStack,
+      item = stack[stack.length - 1];
 
     /* istanbul ignore if */
     if (item instanceof Literal) {
@@ -983,24 +1116,29 @@ JavaScriptCompiler.prototype = {
 
   setupHelper: function(paramSize, name, blockHelper) {
     let params = [],
-        paramsInit = this.setupHelperArgs(name, paramSize, params, blockHelper);
-    let foundHelper = this.nameLookup('helpers', name, 'helper');
+      paramsInit = this.setupHelperArgs(name, paramSize, params, blockHelper);
+    let foundHelper = this.nameLookup('helpers', name, 'helper'),
+      callContext = this.aliasable(
+        `${this.contextName(0)} != null ? ${this.contextName(
+          0
+        )} : (container.nullContext || {})`
+      );
 
     return {
       params: params,
       paramsInit: paramsInit,
       name: foundHelper,
-      callParams: [this.contextName(0)].concat(params)
+      callParams: [callContext].concat(params)
     };
   },
 
   setupParams: function(helper, paramSize, params) {
     let options = {},
-        contexts = [],
-        types = [],
-        ids = [],
-        objectArgs = !params,
-        param;
+      contexts = [],
+      types = [],
+      ids = [],
+      objectArgs = !params,
+      param;
 
     if (objectArgs) {
       params = [];
@@ -1018,7 +1156,7 @@ JavaScriptCompiler.prototype = {
     }
 
     let inverse = this.popStack(),
-        program = this.popStack();
+      program = this.popStack();
 
     // Avoid setting fn and inverse if neither are set. This allows
     // helpers to do a check for `if (options.fn)`
@@ -1066,6 +1204,7 @@ JavaScriptCompiler.prototype = {
 
   setupHelperArgs: function(helper, paramSize, params, useRegister) {
     let options = this.setupParams(helper, paramSize, params);
+    options.loc = JSON.stringify(this.source.currentLocation);
     options = this.objectLiteral(options);
     if (useRegister) {
       this.useRegister('options');
@@ -1080,7 +1219,6 @@ JavaScriptCompiler.prototype = {
   }
 };
 
-
 (function() {
   const reservedWords = (
     'break else new var' +
@@ -1101,21 +1239,27 @@ JavaScriptCompiler.prototype = {
     ' null true false'
   ).split(' ');
 
-  const compilerWords = JavaScriptCompiler.RESERVED_WORDS = {};
+  const compilerWords = (JavaScriptCompiler.RESERVED_WORDS = {});
 
   for (let i = 0, l = reservedWords.length; i < l; i++) {
     compilerWords[reservedWords[i]] = true;
   }
-}());
+})();
 
+/**
+ * @deprecated May be removed in the next major version
+ */
 JavaScriptCompiler.isValidJavaScriptVariableName = function(name) {
-  return !JavaScriptCompiler.RESERVED_WORDS[name] && (/^[a-zA-Z_$][0-9a-zA-Z_$]*$/).test(name);
+  return (
+    !JavaScriptCompiler.RESERVED_WORDS[name] &&
+    /^[a-zA-Z_$][0-9a-zA-Z_$]*$/.test(name)
+  );
 };
 
 function strictLookup(requireTerminal, compiler, parts, type) {
   let stack = compiler.popStack(),
-      i = 0,
-      len = parts.length;
+    i = 0,
+    len = parts.length;
   if (requireTerminal) {
     len--;
   }
@@ -1125,7 +1269,16 @@ function strictLookup(requireTerminal, compiler, parts, type) {
   }
 
   if (requireTerminal) {
-    return [compiler.aliasable('container.strict'), '(', stack, ', ', compiler.quotedString(parts[i]), ')'];
+    return [
+      compiler.aliasable('container.strict'),
+      '(',
+      stack,
+      ', ',
+      compiler.quotedString(parts[i]),
+      ', ',
+      JSON.stringify(compiler.source.currentLocation),
+      ' )'
+    ];
   } else {
     return stack;
   }

lib/handlebars/compiler/printer.js

@@ -24,13 +24,14 @@ PrintVisitor.prototype.pad = function(string) {
 
 PrintVisitor.prototype.Program = function(program) {
   let out = '',
-      body = program.body,
-      i, l;
+    body = program.body,
+    i,
+    l;
 
   if (program.blockParams) {
     let blockParams = 'BLOCK PARAMS: [';
     for (i = 0, l = program.blockParams.length; i < l; i++) {
-       blockParams += ' ' + program.blockParams[i];
+      blockParams += ' ' + program.blockParams[i];
     }
     blockParams += ' ]';
     out += this.pad(blockParams);
@@ -52,11 +53,14 @@ PrintVisitor.prototype.Decorator = function(mustache) {
   return this.pad('{{ DIRECTIVE ' + this.SubExpression(mustache) + ' }}');
 };
 
-PrintVisitor.prototype.BlockStatement =
-PrintVisitor.prototype.DecoratorBlock = function(block) {
+PrintVisitor.prototype.BlockStatement = PrintVisitor.prototype.DecoratorBlock = function(
+  block
+) {
   let out = '';
 
-  out += this.pad((block.type === 'DecoratorBlock' ? 'DIRECTIVE ' : '') + 'BLOCK:');
+  out += this.pad(
+    (block.type === 'DecoratorBlock' ? 'DIRECTIVE ' : '') + 'BLOCK:'
+  );
   this.padding++;
   out += this.pad(this.SubExpression(block));
   if (block.program) {
@@ -66,12 +70,16 @@ PrintVisitor.prototype.DecoratorBlock = function(block) {
     this.padding--;
   }
   if (block.inverse) {
-    if (block.program) { this.padding++; }
+    if (block.program) {
+      this.padding++;
+    }
     out += this.pad('{{^}}');
     this.padding++;
     out += this.accept(block.inverse);
     this.padding--;
-    if (block.program) { this.padding--; }
+    if (block.program) {
+      this.padding--;
+    }
   }
   this.padding--;
 
@@ -115,8 +123,8 @@ PrintVisitor.prototype.CommentStatement = function(comment) {
 
 PrintVisitor.prototype.SubExpression = function(sexpr) {
   let params = sexpr.params,
-      paramStrings = [],
-      hash;
+    paramStrings = [],
+    hash;
 
   for (let i = 0, l = params.length; i < l; i++) {
     paramStrings.push(this.accept(params[i]));
@@ -134,7 +142,6 @@ PrintVisitor.prototype.PathExpression = function(id) {
   return (id.data ? '@' : '') + 'PATH:' + path;
 };
 
-
 PrintVisitor.prototype.StringLiteral = function(string) {
   return '"' + string.value + '"';
 };
@@ -157,7 +164,7 @@ PrintVisitor.prototype.NullLiteral = function() {
 
 PrintVisitor.prototype.Hash = function(hash) {
   let pairs = hash.pairs,
-      joinedPairs = [];
+    joinedPairs = [];
 
   for (let i = 0, l = pairs.length; i < l; i++) {
     joinedPairs.push(this.accept(pairs[i]));

lib/handlebars/compiler/visitor.js

@@ -15,7 +15,14 @@ Visitor.prototype = {
       // Hacky sanity check: This may have a few false positives for type for the helper
       // methods but will generally do the right thing without a lot of overhead.
       if (value && !Visitor.prototype[value.type]) {
-        throw new Exception('Unexpected node type "' + value.type + '" found when accepting ' + name + ' on ' + node.type);
+        throw new Exception(
+          'Unexpected node type "' +
+            value.type +
+            '" found when accepting ' +
+            name +
+            ' on ' +
+            node.type
+        );
       }
       node[name] = value;
     }

lib/handlebars/compiler/whitespace-control.js

@@ -14,18 +14,18 @@ WhitespaceControl.prototype.Program = function(program) {
   let body = program.body;
   for (let i = 0, l = body.length; i < l; i++) {
     let current = body[i],
-        strip = this.accept(current);
+      strip = this.accept(current);
 
     if (!strip) {
       continue;
     }
 
     let _isPrevWhitespace = isPrevWhitespace(body, i, isRoot),
-        _isNextWhitespace = isNextWhitespace(body, i, isRoot),
-
-        openStandalone = strip.openStandalone && _isPrevWhitespace,
-        closeStandalone = strip.closeStandalone && _isNextWhitespace,
-        inlineStandalone = strip.inlineStandalone && _isPrevWhitespace && _isNextWhitespace;
+      _isNextWhitespace = isNextWhitespace(body, i, isRoot),
+      openStandalone = strip.openStandalone && _isPrevWhitespace,
+      closeStandalone = strip.closeStandalone && _isNextWhitespace,
+      inlineStandalone =
+        strip.inlineStandalone && _isPrevWhitespace && _isNextWhitespace;
 
     if (strip.close) {
       omitRight(body, i, true);
@@ -41,7 +41,7 @@ WhitespaceControl.prototype.Program = function(program) {
         // If we are on a standalone node, save the indent info for partials
         if (current.type === 'PartialStatement') {
           // Pull out the whitespace from the final line
-          current.indent = (/([ \t]+$)/).exec(body[i - 1].original)[1];
+          current.indent = /([ \t]+$)/.exec(body[i - 1].original)[1];
         }
       }
     }
@@ -62,17 +62,17 @@ WhitespaceControl.prototype.Program = function(program) {
   return program;
 };
 
-WhitespaceControl.prototype.BlockStatement =
-WhitespaceControl.prototype.DecoratorBlock =
-WhitespaceControl.prototype.PartialBlockStatement = function(block) {
+WhitespaceControl.prototype.BlockStatement = WhitespaceControl.prototype.DecoratorBlock = WhitespaceControl.prototype.PartialBlockStatement = function(
+  block
+) {
   this.accept(block.program);
   this.accept(block.inverse);
 
   // Find the inverse program that is involed with whitespace stripping.
   let program = block.program || block.inverse,
-      inverse = block.program && block.inverse,
-      firstInverse = inverse,
-      lastInverse = inverse;
+    inverse = block.program && block.inverse,
+    firstInverse = inverse,
+    lastInverse = inverse;
 
   if (inverse && inverse.chained) {
     firstInverse = inverse.body[0].program;
@@ -112,9 +112,11 @@ WhitespaceControl.prototype.PartialBlockStatement = function(block) {
     }
 
     // Find standalone else statments
-    if (!this.options.ignoreStandalone
-        && isPrevWhitespace(program.body)
-        && isNextWhitespace(firstInverse.body)) {
+    if (
+      !this.options.ignoreStandalone &&
+      isPrevWhitespace(program.body) &&
+      isNextWhitespace(firstInverse.body)
+    ) {
       omitLeft(program.body);
       omitRight(firstInverse.body);
     }
@@ -125,13 +127,15 @@ WhitespaceControl.prototype.PartialBlockStatement = function(block) {
   return strip;
 };
 
-WhitespaceControl.prototype.Decorator =
-WhitespaceControl.prototype.MustacheStatement = function(mustache) {
+WhitespaceControl.prototype.Decorator = WhitespaceControl.prototype.MustacheStatement = function(
+  mustache
+) {
   return mustache.strip;
 };
 
-WhitespaceControl.prototype.PartialStatement =
-    WhitespaceControl.prototype.CommentStatement = function(node) {
+WhitespaceControl.prototype.PartialStatement = WhitespaceControl.prototype.CommentStatement = function(
+  node
+) {
   /* istanbul ignore next */
   let strip = node.strip || {};
   return {
@@ -141,7 +145,6 @@ WhitespaceControl.prototype.PartialStatement =
   };
 };
 
-
 function isPrevWhitespace(body, i, isRoot) {
   if (i === undefined) {
     i = body.length;
@@ -150,13 +153,15 @@ function isPrevWhitespace(body, i, isRoot) {
   // Nodes that end with newlines are considered whitespace (but are special
   // cased for strip operations)
   let prev = body[i - 1],
-      sibling = body[i - 2];
+    sibling = body[i - 2];
   if (!prev) {
     return isRoot;
   }
 
   if (prev.type === 'ContentStatement') {
-    return (sibling || !isRoot ? (/\r?\n\s*?$/) : (/(^|\r?\n)\s*?$/)).test(prev.original);
+    return (sibling || !isRoot ? /\r?\n\s*?$/ : /(^|\r?\n)\s*?$/).test(
+      prev.original
+    );
   }
 }
 function isNextWhitespace(body, i, isRoot) {
@@ -165,13 +170,15 @@ function isNextWhitespace(body, i, isRoot) {
   }
 
   let next = body[i + 1],
-      sibling = body[i + 2];
+    sibling = body[i + 2];
   if (!next) {
     return isRoot;
   }
 
   if (next.type === 'ContentStatement') {
-    return (sibling || !isRoot ? (/^\s*?\r?\n/) : (/^\s*?(\r?\n|$)/)).test(next.original);
+    return (sibling || !isRoot ? /^\s*?\r?\n/ : /^\s*?(\r?\n|$)/).test(
+      next.original
+    );
   }
 }
 
@@ -184,12 +191,19 @@ function isNextWhitespace(body, i, isRoot) {
 // content is met.
 function omitRight(body, i, multiple) {
   let current = body[i == null ? 0 : i + 1];
-  if (!current || current.type !== 'ContentStatement' || (!multiple && current.rightStripped)) {
+  if (
+    !current ||
+    current.type !== 'ContentStatement' ||
+    (!multiple && current.rightStripped)
+  ) {
     return;
   }
 
   let original = current.value;
-  current.value = current.value.replace(multiple ? (/^\s+/) : (/^[ \t]*\r?\n?/), '');
+  current.value = current.value.replace(
+    multiple ? /^\s+/ : /^[ \t]*\r?\n?/,
+    ''
+  );
   current.rightStripped = current.value !== original;
 }
 
@@ -202,13 +216,17 @@ function omitRight(body, i, multiple) {
 // content is met.
 function omitLeft(body, i, multiple) {
   let current = body[i == null ? body.length - 1 : i - 1];
-  if (!current || current.type !== 'ContentStatement' || (!multiple && current.leftStripped)) {
+  if (
+    !current ||
+    current.type !== 'ContentStatement' ||
+    (!multiple && current.leftStripped)
+  ) {
     return;
   }
 
-  // We omit the last node if it's whitespace only and not preceeded by a non-content node.
+  // We omit the last node if it's whitespace only and not preceded by a non-content node.
   let original = current.value;
-  current.value = current.value.replace(multiple ? (/\s+$/) : (/[ \t]+$/), '');
+  current.value = current.value.replace(multiple ? /\s+$/ : /[ \t]+$/, '');
   current.leftStripped = current.value !== original;
   return current.leftStripped;
 }

lib/handlebars/decorators.js

@@ -3,4 +3,3 @@ import registerInline from './decorators/inline';
 export function registerDefaultDecorators(instance) {
   registerInline(instance);
 }
-

lib/handlebars/decorators/inline.js

@@ -1,4 +1,4 @@
-import {extend} from '../utils';
+import { extend } from '../utils';
 
 export default function(instance) {
   instance.registerDecorator('inline', function(fn, props, container, options) {

lib/handlebars/exception.js

@@ -1,13 +1,26 @@
-
-const errorProps = ['description', 'fileName', 'lineNumber', 'message', 'name', 'number', 'stack'];
+const errorProps = [
+  'description',
+  'fileName',
+  'lineNumber',
+  'endLineNumber',
+  'message',
+  'name',
+  'number',
+  'stack'
+];
 
 function Exception(message, node) {
   let loc = node && node.loc,
-      line,
-      column;
+    line,
+    endLineNumber,
+    column,
+    endColumn;
+
   if (loc) {
     line = loc.start.line;
+    endLineNumber = loc.end.line;
     column = loc.start.column;
+    endColumn = loc.end.column;
 
     message += ' - ' + line + ':' + column;
   }
@@ -24,9 +37,29 @@ function Exception(message, node) {
     Error.captureStackTrace(this, Exception);
   }
 
-  if (loc) {
-    this.lineNumber = line;
-    this.column = column;
+  try {
+    if (loc) {
+      this.lineNumber = line;
+      this.endLineNumber = endLineNumber;
+
+      // Work around issue under safari where we can't directly set the column value
+      /* istanbul ignore next */
+      if (Object.defineProperty) {
+        Object.defineProperty(this, 'column', {
+          value: column,
+          enumerable: true
+        });
+        Object.defineProperty(this, 'endColumn', {
+          value: endColumn,
+          enumerable: true
+        });
+      } else {
+        this.column = column;
+        this.endColumn = endColumn;
+      }
+    }
+  } catch (nop) {
+    /* Ignore if the browser is very particular */
   }
 }
 

lib/handlebars/helpers.js

@@ -15,3 +15,12 @@ export function registerDefaultHelpers(instance) {
   registerLookup(instance);
   registerWith(instance);
 }
+
+export function moveHelperToHooks(instance, helperName, keepHelper) {
+  if (instance.helpers[helperName]) {
+    instance.hooks[helperName] = instance.helpers[helperName];
+    if (!keepHelper) {
+      delete instance.helpers[helperName];
+    }
+  }
+}

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

@@ -1,9 +1,9 @@
-import {appendContextPath, createFrame, isArray} from '../utils';
+import { appendContextPath, createFrame, isArray } from '../utils';
 
 export default function(instance) {
   instance.registerHelper('blockHelperMissing', function(context, options) {
     let inverse = options.inverse,
-        fn = options.fn;
+      fn = options.fn;
 
     if (context === true) {
       return fn(this);
@@ -22,8 +22,11 @@ export default function(instance) {
     } else {
       if (options.data && options.ids) {
         let data = createFrame(options.data);
-        data.contextPath = appendContextPath(options.data.contextPath, options.name);
-        options = {data: data};
+        data.contextPath = appendContextPath(
+          options.data.contextPath,
+          options.name
+        );
+        options = { data: data };
       }
 
       return fn(context, options);

lib/handlebars/helpers/each.js

@@ -1,4 +1,10 @@
-import {appendContextPath, blockParams, createFrame, isArray, isFunction} from '../utils';
+import {
+  appendContextPath,
+  blockParams,
+  createFrame,
+  isArray,
+  isFunction
+} from '../utils';
 import Exception from '../exception';
 
 export default function(instance) {
@@ -8,29 +14,26 @@ export default function(instance) {
     }
 
     let fn = options.fn,
-        inverse = options.inverse,
-        i = 0,
-        ret = '',
-        data,
-        contextPath;
+      inverse = options.inverse,
+      i = 0,
+      ret = '',
+      data,
+      contextPath;
 
     if (options.data && options.ids) {
-      contextPath = appendContextPath(options.data.contextPath, options.ids[0]) + '.';
+      contextPath =
+        appendContextPath(options.data.contextPath, options.ids[0]) + '.';
     }
 
-    if (isFunction(context)) { context = context.call(this); }
+    if (isFunction(context)) {
+      context = context.call(this);
+    }
 
     if (options.data) {
       data = createFrame(options.data);
     }
 
     function execIteration(field, index, last) {
-      // Don't iterate over undefined values since we can't execute blocks against them
-      // in non-strict (js) mode.
-      if (context[field] == null) {
-        return;
-      }
-
       if (data) {
         data.key = field;
         data.index = index;
@@ -42,32 +45,47 @@ export default function(instance) {
         }
       }
 
-      ret = ret + fn(context[field], {
-        data: data,
-        blockParams: blockParams([context[field], field], [contextPath + field, null])
-      });
+      ret =
+        ret +
+        fn(context[field], {
+          data: data,
+          blockParams: blockParams(
+            [context[field], field],
+            [contextPath + field, null]
+          )
+        });
     }
 
     if (context && typeof context === 'object') {
       if (isArray(context)) {
+        for (let j = context.length; i < j; i++) {
+          if (i in context) {
+            execIteration(i, i, i === context.length - 1);
+          }
+        }
+      } else if (global.Symbol && context[global.Symbol.iterator]) {
+        const newContext = [];
+        const iterator = context[global.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, i, i === context.length - 1);
         }
       } else {
         let priorKey;
 
-        for (let key in context) {
-          if (context.hasOwnProperty(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 itermediate keys array.
-            if (priorKey !== undefined) {
-              execIteration(priorKey, i - 1);
-            }
-            priorKey = key;
-            i++;
+        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 itermediate keys array.
+          if (priorKey !== undefined) {
+            execIteration(priorKey, i - 1);
           }
-        }
+          priorKey = key;
+          i++;
+        });
         if (priorKey !== undefined) {
           execIteration(priorKey, i - 1, true);
         }

lib/handlebars/helpers/helper-missing.js

@@ -7,7 +7,9 @@ export default function(instance) {
       return undefined;
     } else {
       // Someone is actually trying to call something, blow up.
-      throw new Exception('Missing helper: "' + arguments[arguments.length - 1].name + '"');
+      throw new Exception(
+        'Missing helper: "' + arguments[arguments.length - 1].name + '"'
+      );
     }
   });
 }

lib/handlebars/helpers/if.js

@@ -1,8 +1,14 @@
-import {isEmpty, isFunction} from '../utils';
+import { isEmpty, isFunction } from '../utils';
+import Exception from '../exception';
 
 export default function(instance) {
   instance.registerHelper('if', function(conditional, options) {
-    if (isFunction(conditional)) { conditional = conditional.call(this); }
+    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 condtional as purely not empty based on the
@@ -15,6 +21,13 @@ export default function(instance) {
   });
 
   instance.registerHelper('unless', function(conditional, options) {
-    return instance.helpers['if'].call(this, conditional, {fn: options.inverse, inverse: options.fn, hash: options.hash});
+    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

@@ -1,7 +1,7 @@
 export default function(instance) {
   instance.registerHelper('log', function(/* message, options */) {
     let args = [undefined],
-        options = arguments[arguments.length - 1];
+      options = arguments[arguments.length - 1];
     for (let i = 0; i < arguments.length - 1; i++) {
       args.push(arguments[i]);
     }
@@ -14,6 +14,6 @@ export default function(instance) {
     }
     args[0] = level;
 
-    instance.log(... args);
+    instance.log(...args);
   });
 }

lib/handlebars/helpers/lookup.js

@@ -1,5 +1,9 @@
 export default function(instance) {
-  instance.registerHelper('lookup', function(obj, field) {
-    return obj && obj[field];
+  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

@@ -1,8 +1,20 @@
-import {appendContextPath, blockParams, createFrame, isEmpty, isFunction} from '../utils';
+import {
+  appendContextPath,
+  blockParams,
+  createFrame,
+  isEmpty,
+  isFunction
+} from '../utils';
+import Exception from '../exception';
 
 export default function(instance) {
   instance.registerHelper('with', function(context, options) {
-    if (isFunction(context)) { context = context.call(this); }
+    if (arguments.length != 2) {
+      throw new Exception('#with requires exactly one argument');
+    }
+    if (isFunction(context)) {
+      context = context.call(this);
+    }
 
     let fn = options.fn;
 
@@ -10,7 +22,10 @@ export default function(instance) {
       let data = options.data;
       if (options.data && options.ids) {
         data = createFrame(options.data);
-        data.contextPath = appendContextPath(options.data.contextPath, options.ids[0]);
+        data.contextPath = appendContextPath(
+          options.data.contextPath,
+          options.ids[0]
+        );
       }
 
       return fn(context, {

lib/handlebars/internal/create-new-lookup-object.js

@@ -0,0 +1,11 @@
+import { extend } from '../utils';
+
+/**
+ * Create a new object with "null"-prototype to avoid truthy results on prototype properties.
+ * The resulting object can be used with "object[property]" to check if a property exists
+ * @param {...object} sources a varargs parameter of source objects that will be merged
+ * @returns {object}
+ */
+export function createNewLookupObject(...sources) {
+  return extend(Object.create(null), ...sources);
+}

lib/handlebars/internal/proto-access.js

@@ -0,0 +1,70 @@
+import { createNewLookupObject } from './create-new-lookup-object';
+import * as logger from '../logger';
+
+const loggedProperties = Object.create(null);
+
+export function createProtoAccessControl(runtimeOptions) {
+  let defaultMethodWhiteList = Object.create(null);
+  defaultMethodWhiteList['constructor'] = false;
+  defaultMethodWhiteList['__defineGetter__'] = false;
+  defaultMethodWhiteList['__defineSetter__'] = false;
+  defaultMethodWhiteList['__lookupGetter__'] = false;
+
+  let defaultPropertyWhiteList = Object.create(null);
+  // eslint-disable-next-line no-proto
+  defaultPropertyWhiteList['__proto__'] = false;
+
+  return {
+    properties: {
+      whitelist: createNewLookupObject(
+        defaultPropertyWhiteList,
+        runtimeOptions.allowedProtoProperties
+      ),
+      defaultValue: runtimeOptions.allowProtoPropertiesByDefault
+    },
+    methods: {
+      whitelist: createNewLookupObject(
+        defaultMethodWhiteList,
+        runtimeOptions.allowedProtoMethods
+      ),
+      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;
+  }
+  logUnexpecedPropertyAccessOnce(propertyName);
+  return false;
+}
+
+function logUnexpecedPropertyAccessOnce(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/wycats/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

@@ -1,3 +1,5 @@
+import { indexOf } from './utils';
+
 let logger = {
   methodMap: ['debug', 'info', 'warn', 'error'],
   level: 'info',
@@ -5,7 +7,7 @@ let logger = {
   // Maps a given level value to the `methodMap` indexes above.
   lookupLevel: function(level) {
     if (typeof level === 'string') {
-      let levelMap = logger.methodMap.indexOf(level.toLowerCase());
+      let levelMap = indexOf(logger.methodMap, level.toLowerCase());
       if (levelMap >= 0) {
         level = levelMap;
       } else {
@@ -20,12 +22,16 @@ let logger = {
   log: function(level, ...message) {
     level = logger.lookupLevel(level);
 
-    if (typeof console !== 'undefined' && logger.lookupLevel(logger.level) <= level) {
+    if (
+      typeof console !== 'undefined' &&
+      logger.lookupLevel(logger.level) <= level
+    ) {
       let method = logger.methodMap[level];
-      if (!console[method]) {   // eslint-disable-line no-console
+      // eslint-disable-next-line no-console
+      if (!console[method]) {
         method = 'log';
       }
-      console[method](...message);    // eslint-disable-line no-console
+      console[method](...message); // eslint-disable-line no-console
     }
   }
 };