feat: [#825] Attribute iframe.sandbox should return a DOMTokenList #1375
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
According to the specifications:
https://html.spec.whatwg.org/multipage/iframe-embed-object.html#attr-iframe-sandbox
https://developer.mozilla.org/en-US/docs/Web/HTML/Element/iframe#sandbox
The sandbox attribute of the HTMLIFrameElement should return a DOMTokenList.
Additionally, although sandbox works like a regular DOMTokenList, it is checked after the attribute is set. If there are tokens that do not comply with the specification, an error message will be printed (but no error will be thrown).
There is a bug in DOMTokenList where, after setting the value, operations like sandbox[0] do not take effect. So we need an update of the indices.