763943 - Show compatibility warning if an add-on uses E4X

Status: VERIFIED FIXED

(addons.mozilla.org Graveyard :: Compatibility Tools, defect)

Description

[Kris Maglione [:kmag]]

While E4X still works on Gecko 15, the landing of compartment per global broke so many common use cases that any use of E4X whatsoever should block the compatibility bump and generate a warning along the lines of:

As of Gecko 15, it is no longer possible to pass E4X objects between most contexts, including different chrome windows or JavaScript modules. See [[bug 650353]] and [[bug 613142]].

Comment 1

[Jorge Villalobos [:jorgev] (he/him)]

What do you suggest we look for?

Comment 2

[Kris Maglione [:kmag]]

Any occurrence of an E4X node or operation in the parse tree should do it. Basically any of these:

    "XMLEscape": node(branches=("expression", ), action=actions._expression,
                      returns=True),
    "XMLDefaultDeclaration": node(branches=("namespace", )),
    "XMLQualifiedIdentifier": node(branches=("left", "right")),
    "XMLFunctionQualifiedIdentifier": node(branches=("right", )),

    "XMLAttributeSelector": node(branches=("attribute", ), returns=True),
    "XMLFilterExpression": node(branches=("left", "right"), returns=True),

    "XMLElement": node(branches=("contents", ), returns=True),
    "XMLList": node(branches=("contents", )),
    "XMLStartTag": node(branches=("contents", )),
    "XMLEndTag": node(branches=("contents", )),
    "XMLPointTag": node(branches=("contents", )),
    "XMLName": node(branches=("contents", )),

There shouldn't be a need to warn more than once.

Comment 3

[Jorge Villalobos [:jorgev] (he/him)]

This is a compatibility warning, so the add-on should still be upgraded in this case.

Message:

It is no longer possible to pass E4X objects between most contexts, including different chrome windows or JavaScript modules. You should also be aware that E4X is in a quick deprecation path. See <LINK> for more information.

Link: https://developer.mozilla.org/en-US/docs/E4X

Affected add-on:

https://addons.mozilla.org/en-US/firefox/addon/pentadactyl/

Comment 4

[Matt Basta [:basta]]

Merged:

https://github.com/mozilla/amo-validator/commit/3f6231502aa357ca1657857135abd39bc1d45c2e

Comment 5

[Kris Maglione [:kmag]]

Attachment: Test add-on

Summary:
------------------------------
Detected type: Extension/Multi-Extension
------------------------------
Test failed! Errors:

Warning: E4X Deprecated

E4X has been deprecated and will be disabled by default for content in Gecko 16, and will be removed in Gecko 17.
	Tier:	3
	File:	bootstrap.js
	Line:	7
	Column:	10
	Context:
	> 
	> var foo = <foo>
	> </foo>;