[WebIDL] add tests for is an array index abstract operation

[tobie]

References whatwg/webidl#517.

[ghost]

Build PASSED

Started: 2018-02-08 23:43:25
Finished: 2018-02-08 23:51:33

Failing Jobs

• MicrosoftEdge:16.16299

Unstable Results

Browser: "Microsoftedge 16.16299" (failures allowed)

View in: WPT PR Status | TravisCI

Test	Subtest	Results	Messages
/WebIDL/ecmascript-binding/legacy-platform-object.html		TIMEOUT: 1 OK: 9
	[[GetOwnProperty]] with getters and no setters	FAIL: 9	assert_equals: (assert_prop_desc_equals: property 'writable') expected false but got true
	[[GetOwnProperty]] with indexed property getters and setters	PASS: 9
	[[GetOwnProperty]] with named property getters and setters	PASS: 9
	Test [[DefineOwnProperty]] with indexed property setter support.	FAIL: 9	assert_throws: function "() => Object.defineProperty(select, "0", {get: () => {}})" did not throw
	Test [[DefineOwnProperty]] with no indexed property setter support.	FAIL: 9	assert_equals: (assert_prop_desc_equals: property 'writable') expected false but got true
	Test 'is an array index' abstract operation.	FAIL: 9	Unable to get property 'id' of undefined or null reference

[TimothyGu]

I'd rather test this specifically for document.all, in which case a lot of these tests are already included:

https://github.com/w3c/web-platform-tests/blob/0c874a2e11885dc750902ae6c119f20affc6b49e/html/infrastructure/common-dom-interfaces/collections/htmlallcollection.html#L93-L100

[foolip]

Tests for document.all are in #9303

[foolip]

Don't review or merge it though, it's an automatic export!

[domenic]

@TimothyGu why is testing document.all specifically a good idea here? I'd rather test a less-crazy object in the WebIDL/ tests, leaving document.all tests to a dedicated file.

[TimothyGu]

@domenic It’s not, I agree with you. But this PR currently tests document.all.

[domenic]

Hmm, I guess I misunderstood your comment then, OK.

[tobie]

I’m fine testing using another object. Which one would you suggest that allows testing the same things?

[domenic]

Anything with an array index, right? I guess you'd ideally test all the call sites: get/set/define/delete. Maybe one object with an indexed getter only, and one object with an indexed setter? So like, NodeList and Storage?

[foolip]

This is tested by #9303. Testing some other object that document.all would be nice.

[foolip]

@tobie is this something you'd like to finish if I do review, or should we close it?