Xidorn Quan [:xidorn] UTC+11 Assignee
	Description • 8 years ago

Steps to reproduce:
1. Open Web Console
2. Enter "new Response(null, {status: 204})"

Expected result:
return a Response object

Actual result:
TypeError: Response body is given with a null body status.


This is an issue for Fetch, but I have no idea what component Fetch belongs to, so just put in ServiceWorker.

	Xidorn Quan [:xidorn] UTC+11 Assignee
	Comment 1 • 8 years ago

I guess the issue is at [1].

The spec says in [2]:
> If body is non-null, run these substeps:
but the code at [1] only checks whether the value is passed.


[1] https://dxr.mozilla.org/mozilla-central/rev/8a494adbc5cced90a4edf0c98cffde906bf7f3ae/dom/fetch/Response.cpp#194
[2] https://fetch.spec.whatwg.org/#dom-response

	Ben Kelly [:bkelly, not reviewing]
	Comment 2 • 8 years ago

Xidorn, I believe null is being converted to "null" because BodyInit is not a nullable type and DOMString is one of its union types.  If you do this, then it works:

  var r = new Response(undefined, { status: 204 })

Does this make sense?

	Ben Kelly [:bkelly, not reviewing]
	Comment 3 • 8 years ago

And fetch just goes in Core/DOM

	Ben Kelly [:bkelly, not reviewing]
	Comment 4 • 8 years ago

Except the constructor itself has a nullable operator on the BodyInit type.

	Ben Kelly [:bkelly, not reviewing]
	Comment 5 • 8 years ago

Which we are missing in our webidl:

https://dxr.mozilla.org/mozilla-central/source/dom/webidl/Response.webidl#10

Seems we need `optional BodyInit? body` there.

	chrsmrtn
	Comment 6 • 6 years ago

I too have run into this issue. Please refer to the following specs for fetch. The body getter must return null or stream, so 'undefined' will never occur [1]. Also the status reference for response says that it must be null for 101, 204, 205, or 304 [2]. And finally body is allowed to be null, and "body is said to be done if body is null or body’s stream is closed or errored" [3], So creating a Response with a body of 'undefined' is actually not "done" as the spec describes

[1] https://fetch.spec.whatwg.org/#dom-body-body
[2] https://fetch.spec.whatwg.org/#concept-status
[3] https://fetch.spec.whatwg.org/#concept-body

	chrsmrtn
	Comment 7 • 6 years ago

noted that Chrome and Edge both allow null as the body when building a Response object

	chrsmrtn
	Comment 8 • 6 years ago

Please ignore my previous comment. This is not about what other browsers allow, but rather how Firefox has implemented the standard. Cheers

	Xidorn Quan [:xidorn] UTC+11 Assignee
	Comment 10 • 6 years ago

If there is no test checking this, I'll add a wpt later.

	Xidorn Quan [:xidorn] UTC+11 Assignee
	Comment 11 • 6 years ago

Looks like there is no such test at the moment...

	Ben Kelly [:bkelly, not reviewing]
	Comment 13 • 6 years ago
mozreview-review

Comment on attachment 8942406 [details]
Bug 1303025 - Accept null for body param in constructor of Response.

https://reviewboard.mozilla.org/r/212712/#review218884

Thanks!

	Pulsebot
	Comment 14 • 6 years ago

Pushed by xquan@mozilla.com:
https://hg.mozilla.org/integration/autoland/rev/62f5c4a36823
Accept null for body param in constructor of Response. r=bkelly

	Cosmin Sabou [:CosminS]
	Comment 15 • 6 years ago
bugherder

https://hg.mozilla.org/mozilla-central/rev/62f5c4a36823

	Chris Mills [:cmills]
	Comment 16 • 6 years ago

I've documented this by:

* Updating the description and support info on the constructor page: https://developer.mozilla.org/en-US/docs/Web/API/Response/Response
* Adding a note to the Fx59 rel notes: https://developer.mozilla.org/en-US/Firefox/Releases/59#DOM

Let me know if this is OK, thanks!

	Xidorn Quan [:xidorn] UTC+11 Assignee
	Comment 17 • 6 years ago

Looks good, thanks.