This commmit adds the runtime options
- `allowProtoPropertiesByDefault` (boolean, default: false) and
- `allowProtoMethodsByDefault` (boolean, default: false)`
which can be used to allow access to prototype properties and
functions in general.
Specific properties and methods can still be disabled from access
via `allowedProtoProperties` and `allowedProtoMethods` by
setting the corresponding values to false.
The methods `constructor`, `__defineGetter__`, `__defineSetter__`, `__lookupGetter__`
and the property `__proto__` will be disabled, even if the allow...ByDefault-options
are set to true. In order to allow access to those properties and methods, they have
to be explicitly set to true in the 'allowedProto...'-options.
A warning is logged when the a proto-access it attempted and denied
by default (i.e. if no option is set by the user to make the access
decision explicit)
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
Reintroduce "merge" function, no called "mergeIfNeeded", that only creates a new partials
object if both "env.partials" and "options.partials" are set.
closes#1598
When authoring tooling that parses Handlebars files and emits Handlebars
files, you often want to preserve the **exact** formatting of the input.
The changes in this commit add a new method to the `Handlebars`
namespace: `parseWithoutProcessing`. Unlike, `Handlebars.parse` (which
will mutate the parsed AST to apply whitespace control) this method will
parse the template and return it directly (**without** processing
😉).
For example, parsing the following template:
```hbs
{{#foo}}
{{~bar~}} {{baz~}}
{{/foo}}
```
Using `Handlebars.parse`, the AST returned would have truncated the
following whitespace:
* The whitespace prior to the `{{#foo}}`
* The newline following `{{#foo}}`
* The leading whitespace before `{{~bar~}}`
* The whitespace between `{{~bar~}}` and `{{baz~}}`
* The newline after `{{baz~}}`
* The whitespace prior to the `{{/foo}}`
When `Handlebars.parse` is used from `Handlebars.precompile` or
`Handlebars.compile`, this whitespace stripping is **very** important
(these behaviors are intentional, and generally lead to better rendered
output).
When the same template is parsed with
`Handlebars.parseWithoutProcessing` none of those modifications to the
AST are made. This enables "codemod tooling" (e.g. `prettier` and
`ember-template-recast`) to preserve the **exact** initial formatting.
Prior to these changes, those tools would have to _manually_ reconstruct
the whitespace that is lost prior to emitting source.
The use of arrays was incorrect for the data type and causing problems when hash keys conflicted with array behaviors.
Fixes#1194
(cherry picked from commit 768ddbd661)
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
* Added support for iterable object in {{#each}} helper
Currently {{#each}} helper supports either arrays, or objects,
however nowadays you can define custom iterable objects by overriding
a special method called Symbol.iterator, which results in empty result
being rendered.
* improved a test for iterables in {{#each}} returning empty result
* #each helper: using ES5 instead of generator functions in tests
* #each helper: using ES5 in the helper itself
- "container" is an internal object that is most likely
not accessible through templateing (unlike the proto of "Object", which might be.)
In order to prevent overriding this method, we
use "propertyIsEnumerable" from the constructor.
- context.propertyIsEnumerable can be replaced
via __definedGetter__
- This is a fix specific to counter a known RCE exploit.
Other fixes will follow.
closes#1563
- The version-range above have compiler version 7 and
precompiled templates expecte the (block)
HelperMissing-functions in "helpers" and not in "container.hooks".
- Handlebars now accepts precompiled templates of version 7.
- If a precompiled template with version 7 is loaded,
the (block)HelperMissing-functions are kept in "helpers"
- Handlebars.VM is actually not part of the API,
but Handlebars.VM.resolvePartial is mentioned
in the documentation and is thus now treated
as part of the API.
Closes#1534
- The "lookup" helper could also be used to run a remote code execution
by manipulating the template. The same check as for regular
path queries now also is done in the "lookup"-helper
Nils Knappmeier
ole-martin
Robert Jackson
kpdecker
Hannah Wolfe
sohibe
antelle
Caleb Mazalevskis
Andrew Leedham
Timothy Lindvall
Qiang Li