Disallow access to prototype properties and methods by default.
Access to properties is always checked via
`Object.prototype.hasOwnProperty.call(parent, propertyName)`.
New runtime options:
- **allowedProtoMethods**: a string-to-boolean map of property-names that are allowed if they are methods of the parent object.
- **allowedProtoProperties**: a string-to-boolean map of property-names that are allowed if they are properties but not methods of the parent object.
```js
const template = handlebars.compile('{{aString.trim}}')
const result = template({ aString: ' abc ' })
// result is empty, because trim is defined at String prototype
```
```js
const template = handlebars.compile('{{aString.trim}}')
const result = template({ aString: ' abc ' }, {
allowedProtoMethods: {
trim: true
}
})
// result = 'abc'
```
Implementation details: The method now "container.lookupProperty"
handles the prototype-checks and the white-lists. It is used in
- JavaScriptCompiler#nameLookup
- The "lookup"-helper (passed to all helpers as "options.lookupProperty")
- The "lookup" function at the container, which is used for recursive lookups in "compat" mode
Compatibility:
- **Old precompiled templates work with new runtimes**: The "options.lookupPropery"-function is passed to the helper by a wrapper, not by the compiled templated.
- **New templates work with old runtimes**: The template contains a function that is used as fallback if the "lookupProperty"-function cannot be found at the container. However, the runtime-options "allowedProtoProperties" and "allowedProtoMethods" only work with the newest runtime.
BREAKING CHANGE:
- access to prototype properties is forbidden completely by default
fixes#1548
- add a guard to show readable syntax error for if / unless helper
- prevents against 3 different errors that can be generated by different systax errors
In 4.4.4 the block-contents was matched with an eager match, which means
that with multiple raw-blocks of the same kind, the block was spanned
over the first ending-tag until the last one.
This commit replaces this by a non-eager match.
closes#1579
Creating a new depth value seems to confuse users as they don’t expect things like `if` to require multiple `..` to break out of. With the change, we avoid pushing a context to the depth list if it’s already on the top of the stack, effectively removing cases where `.` and `..` are the same object and multiple `..` references are required.
This is a breaking change and all templates that utilize `..` will have to check their usage and confirm that this does not break desired behavior. Helper authors now need to take care to return the same context value whenever it is conceptually the same and to avoid behaviors that may execute children under the current context in some situations and under different contexts under other situations.
Fixes#1028
Converts the tool chain to use babel, eslint, and webpack vs. the previous proprietary solutions.
Additionally begins enforcing additional linting concerns as well as updates the code to reflect these rules.
Fixes#855Fixes#993
Allow the precompiler to generate source maps when the srcFile parameter is passed.
This refactors large chunks of the code generation pipeline, allowing metadata to be associated with code chunks as well as breaking out much of the code generation logic into a separate helper.
All helper calls will have access to `options.name` which is the first id value of the mustache operation.
As part of this the helperMissing call has been simplified to remove the indexed name in order to optimize the call. This is a breaking change.
Fixes#634
The idea is that the environment wraps up the mutable stuff in
Handlebars (like the helpers) and that you could theoretically create a
new one at any time and pass it in to Handlebars.template.
Every test makes a new environment and uses it in template compilation.