Closed Bug 1630525 Opened 2 years ago Closed 3 months ago

BrowsingContext actors returns different traits objects in `form()` and `attach()`


(DevTools :: General, task, P3)



(firefox93 fixed)

93 Branch
Tracking Status
firefox93 --- fixed


(Reporter: jdescottes, Assigned: bomsy)


(Blocks 1 open bug)


(Whiteboard: [not-a-fission-bug])


(1 file)

The BrowsingContextTargetActor defines a this.traits property at :

    this.traits = {
      reconfigure: true,
      // Supports frame listing via `listFrames` request and `frameUpdate` events
      // as well as frame switching via `switchToFrame` request
      frames: true,
      // Supports the logInPage request.
      logInPage: true,
      // Supports watchpoints in the server for Fx71+
      watchpoints: true,

This this.traits is returned as part of the response for the attach request at

And the front seems to handle it appropriately:

However, there is another traits object, this time returned by the form() call:

    const response = {
      actor: this.actorID,
      traits: {
        // FF64+ exposes a new trait to help identify BrowsingContextActor's inherited
        // actorss from the client side.
        isBrowsingContext: true,

The BrowsingContext front doesn't handle this, but (!) we have the getTrait feature on target-mixin (base class for the BrowsingContextTargetFront) which reads this.targetForm.traits, and since targetForm is a reference to the form() response, it will be able to get the isBrowsingContext trait.

It's confusing to have traits split like this. We should move all traits to the form response, so that they can be checked via getTrait.


Severity: -- → normal
Fission Milestone: --- → M6

Adding dt-fission whiteboard tag to DevTools bugs that mention Fission or block Fission meta bugs but don't already have a dt-fission whiteboard tag.

Whiteboard: dt-fission

Moving these DevTools Fission bugs from Fission's old M6 Nightly milestone to M7 Beta. I am assuming these bugs would have the dt-fission-m2-mvp whiteboard tag if they were Fission Nightly blockers.

Fission Milestone: M6 → M7

Bulk change of all bugs with whiteboard tag of dt-fission to Fission MVP milestone.

Fission Milestone: M7 → MVP

Removing the fission tags and milestones from this bug, it's a generic devtools task not specific to fission.

Fission Milestone: MVP → ---
Whiteboard: dt-fission

(In reply to Julian Descottes [:jdescottes] from comment #5)

Removing the fission tags and milestones from this bug, it's a generic devtools task not specific to fission.

In that case, adding [fission-] whiteboard tag (so this bug doesn't show up in Fission bug triage simply because the bug summary contains the substring "BrowsingContext").

Whiteboard: [fission-]

Not a Fission bug

Whiteboard: [fission-] → [not-a-fission-bug]

This has been the source of intermittents as the traits set from attach are sometimes late, Bug 1726220 one such.

Blocks: 1726220

The traits set on attach have been a source of intermittent failures.
See Bug 1726220

Assignee: nobody → hmanilla
Blocks: 1591973
Pushed by
[devtools] Merge all the BrowsingContext traits to the form() r=ochameau
Closed: 3 months ago
Resolution: --- → FIXED
Target Milestone: --- → 93 Branch
Duplicate of this bug: 1726220
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