restartOnFileChange doesn't work after run completes normally

I just upgraded to 0.13.11 and tried the restartOnFileChange option out for the first time.

An excerpt from my karma.conf.js is:

  autoWatch: true,
  singleRun: false,
  restartOnFileChange: true
}

When I kick off a test run, and then quickly edit/save a watched file; I see that the current run is cancelled and a new run starts, as per the docs.

I can repeat this process any number of times; with the same results each time (current run is cancelled, new run starts).

However, if I let the current run continue all the way through to completion; then make a change to a watched file, a new run will start, but it doesn’t run any tests.

Example console output is below. It shows:

1. the end of a successful run (Finished in 39.126 secs, 1325 tests completed)
2. a change detected in the file foo.js
3. another run triggered, but with 0 tests completed:

Finished in 39.136 secs / 1.009 secs

SUMMARY:
✔ 1325 tests completed
19 10 2015 16:42:45.754:INFO [watcher]: Changed file "foo.js".

Finished in 0.002 secs / 0 secs

SUMMARY:
✔ 0 tests completed

[nobuti]

Still failing.

[solo-md]

Let me put here a comment on how this issue happens.

Step by step what happens (karma 2.0.4) and why the issue appears:

1. File changes.

2. lib/server.js line 304 : file_list_modified event is handled

3. lib/server.js line 306 : the handler checks config.restartOnFileChange (this one is true in our case)

4. lib/server.js line 307 : Server emits STOP event

5. lib/server.js line 309 : Server.executor.schedule() -> lib/executor.js line 34: capturedBrowsers.setAllToExecuting() -> lib/browser_collection.js line 36: set browser state to EXECUTING

6. static/karma.js line 235 : STOP event (emitted in step 4) is handled

7. static/karma.js line 236 : karma.complete method is called

8. static/karma.js line 204: karma emits COMPLETE event to the socket

9. lib/browser.js line 255 : COMPLETE event (emitted in step 8) is handled wtih onComplete function

10. lib/browser.js line 117 : onComplete method set the browser state to READY

11. Now the tests are started normally,lib/browser.js onStart method creates a new Result (line 101), and stores the total count of the specs to run…

12. Each spec is completed and the lib/browser.js has a notification about it in onResult (line 185). But in case if the browser state is READY, the onResult method just ignores that result: see lib/browser.js lines 190-193 comment:

// ignore - probably results from last run (after server disconnecting)
    if (this.isReady()) {
      return
    }

So, once the restartOnFileChange config is set to TRUE, on the second run all the spec results are ignored, and the number of executed specs will be always 0.