Taking a look.

It was a part of the initial skeleton code where the getters threw NOT_IMPLEMENTED. The methods are wrong anyway since .forget() will unset the fields.

This way SetBackpressureChangePromise can be removed which is only exposed for that function.

Depends on D153972

Depends on D153973

Per the Streams spec, other specs that want to implement custom TransformStream should use GenericTransformStream mixin and store a new TransformStream in a slot. This implements the latter part.

Depends on D153974

Other methods probably should do the same, but for now this fulfills the test requirement. The rest is (or should be) tracked by https://bugzilla.mozilla.org/show_bug.cgi?id=1756661.

Depends on D153782

Backed out 6 changesets (Bug 1486949) for causing failures in test_serviceworker_interfaces.html CLOSED TREE

Push with failures: https://treeherder.mozilla.org/jobs?repo=autoland&group_state=expanded&collapsedPushes=842382&selectedTaskRun=b660VxHnSSimsFlrlxjiVQ.0&resultStatus=testfailed%2Cbusted%2Cexception%2Cretry%2Cusercancel&revision=73cb8cf7a3f0fc8f39eb6127560b9b6c41279371

Log: https://treeherder.mozilla.org/logviewer?job_id=387045300&repo=autoland&lineNumber=3215

Backout: https://hg.mozilla.org/integration/autoland/rev/3fb7418cbf12d68530a6c5a63a00e918ad030897

Backed out for causing hazard bustage on TextDecoderStream.cpp

• backout: https://hg.mozilla.org/integration/autoland/rev/fd039fcc270224d96e629a83d8cfe7f67f5c74f1
• push: https://treeherder.mozilla.org/jobs?repo=autoland&group_state=expanded&revision=e3dc48b94eef2e4d18792b3b955db5bac9f41f64
• push where the Hazard job run: https://treeherder.mozilla.org/jobs?repo=autoland&group_state=expanded&selectedTaskRun=ZmvSSiBxRRmXXwK7kjXklg.0&revision=c6b6ee57a7697347249bfda1793c2dba3a0056e2&searchStr=linux%2Cx64%2Cdebug%2Chazard-linux64-haz%2Fdebug%2Ch
• failure log: https://treeherder.mozilla.org/logviewer?job_id=387112248&repo=autoland&lineNumber=98002

[task 2022-08-12T03:23:47.069Z] TinderboxPrint: rooting hazards<br/>1
[task 2022-08-12T03:23:47.069Z] TinderboxPrint: (unsafe references to unrooted GC pointers)<br/>248
[task 2022-08-12T03:23:47.069Z] TinderboxPrint: (unnecessary roots)<br/>1154
[task 2022-08-12T03:23:47.069Z] TinderboxPrint: missing expected hazards<br/>0
[task 2022-08-12T03:23:47.069Z] TinderboxPrint: heap write hazards<br/>0
[task 2022-08-12T03:23:47.071Z] TEST-UNEXPECTED-FAIL | hazards | unrooted 'bufferSource' of type 'mozilla::dom::OwningArrayBufferViewOrArrayBuffer' live across GC call at dom/encoding/TextDecoderStream.cpp:62
[task 2022-08-12T03:23:47.071Z] TEST-UNEXPECTED-FAIL | hazards | 1 rooting hazards detected
[task 2022-08-12T03:23:47.071Z] TinderboxPrint: documentation<br/><a href='https://wiki.mozilla.org/Javascript:Hazard_Builds#Diagnosing_a_rooting_hazards_failure'>static rooting hazard analysis failures</a>, visit "Inspect Task" link for hazard details

According to glandium, Firefox still runs on at least one big-endian architecture, so the bit that uses a UTF16_LE decoder to read host-endian char16_t data should be ifdefed to use UTF16_BE on big-endian targets.

According to glandium, Firefox still runs on at least one big-endian architecture, so the bit that uses a UTF16_LE decoder to read host-endian char16_t data should be ifdefed to use UTF16_BE on big-endian targets.

Thanks! One more reason I'd be happier if this could be done in encoding-rs side (getting a method receiving char16_t* and supporting pending high surrogate), but for now let's live with this if that's too hard.

https://hg.mozilla.org/mozilla-central/rev/f0358540ed32
https://hg.mozilla.org/mozilla-central/rev/89263329adf7
https://hg.mozilla.org/mozilla-central/rev/5f01a7b13b7b
https://hg.mozilla.org/mozilla-central/rev/0b84f5bf45f3
https://hg.mozilla.org/mozilla-central/rev/07a90fe2d68e
https://hg.mozilla.org/mozilla-central/rev/5bf69788ffb1

FYI docs work for this was done in https://github.com/mdn/content/issues/20572 - as this was already documented mostly just browser compatibility update.