992223 - Work around Inspector and Style Inspector test failures before switching Task.jsm to use Promise.jsm

Status: RESOLVED FIXED

(DevTools :: Inspector, defect)

Description

[:Paolo Amadini]

The Inspector and Style Inspector browser-chrome tests have several intermittent failures that are already very frequent, and are made much more frequent in Windows optimized builds when Task.jsm is changed by bug 887923 to use Promise.jsm.

There are currently 23 intermittent failures open, that I've collected as dependencies of bug 992211, that may or may not have a common underlying cause. I did some tests and a quick survey of the code, and did not find anything that could be obviously causing the failures. In any case, fixing them probably requires a relevant effort, even if done by the team that originally worked on the code.

Landing bug 887923 is very important:
 - It blocks extending the use of Task in devtools (bug 988048, bug 991797)
 - It blocks the eradication of old "sync" promises (bug 881047)
 - Any new Task-based code introduced from now on may unintentionally rely
   on the incorrect behavior of the current implementation, making it more
   difficult to switch to the correct implementation in the future
 - The "catch" method is unavailable on promises returned by Task.spawn.

Unless any brilliant solution is found to fix all the tests, my proposal
is to disable the above tests on Windows optimized builds (and maybe debug
builds if the increase in frequency is also relevant there).

This will allow us to complete the Promise/Task conversions in time for Firefox 31 ESR.

Comment 1

[Nick Fitzgerald [:fitzgen] [⏰PST; UTC-8]]

I don't know anything about these tests.

Comment 2

[Joe Walker [:jwalker]]

Moving to Inspector component, and clearing the needinfo for Heather and DCamp and assigning to Patrick. Although I'm very tempted to just dup this to bug 988313, which I suspect will solve the problem.

Comment 3

[:Paolo Amadini]

(In reply to Joe Walker [:jwalker] from comment #2)
> Although I'm very tempted to just dup this to bug 988313, which I suspect will solve the problem.

Ah, bug 988313 is great work, and with good timing! We should still keep this bug open to see if bug 988313 solved the issues that prevent bug 887923 from landing. I just started a combined tryserver build:

https://tbpl.mozilla.org/?tree=Try&rev=2b2a87446d24

Comment 4

[:Paolo Amadini]

Bug 988313 solved the concerns here!