Some FocusTracker and TabBar unittests fail in master on OS X with latest Firefox

I'm using OS X 10.14, and the latest version of Firefox (69). On master, I recently noticed that a few dozen of the unittest for the FocusTracker and TabBar widgets were failing:

SUMMARY:
✔ 760 tests completed
✖ 34 tests failed

FAILED TESTS:
  @phosphor/widgets
    FocusTracker
      #currentChanged
        ✖ should be emitted when the current widget has changed
          Firefox 69.0.0 (Mac OS X 10.14.0)
        expected null to not equal null
        AssertionError@build/bundle.test.js:21511:13
        module.exports/Assertion.prototype.assert@build/bundle.test.js:39332:13
        assertEqual@build/bundle.test.js:39849:12
        module.exports/ctx[name]@build/bundle.test.js:43285:25
        @build/bundle.test.js:31062:48

      #activeChanged
        ✖ should be emitted when the active widget has changed
          Firefox 69.0.0 (Mac OS X 10.14.0)
        expected null to not equal null
        AssertionError@build/bundle.test.js:21511:13
        module.exports/Assertion.prototype.assert@build/bundle.test.js:39332:13
        assertEqual@build/bundle.test.js:39849:12
        module.exports/ctx[name]@build/bundle.test.js:43285:25
        @build/bundle.test.js:31093:48

...

The strange thing is that I don't see these failures when testing using Chrome, and I don't see the failures in the CI run on the commits I made in PR #437, even though the CI also uses Firefox. Not sure what's going on.

The rest of the unittest failure log

✖ should be emitted when the active widget is set to null Firefox 69.0.0 (Mac OS X 10.14.0) expected null to not equal null AssertionError@build/bundle.test.js:21511:13 module.exports/Assertion.prototype.assert@build/bundle.test.js:39332:13 assertEqual@build/bundle.test.js:39849:12 module.exports/ctx[name]@build/bundle.test.js:43285:25 @build/bundle.test.js:31107:48 #currentWidget ✖ should be set to the widget that gained focus Firefox 69.0.0 (Mac OS X 10.14.0) expected { Object (_flags, _layout, ...) } to equal { Object (_flags, _layout, ...) } AssertionError@build/bundle.test.js:21511:13 module.exports/Assertion.prototype.assert@build/bundle.test.js:39332:13 assertEqual@build/bundle.test.js:39849:12 module.exports/ctx[name]@build/bundle.test.js:43285:25 @build/bundle.test.js:31146:57 ✖ should revert to the previous widget if the current widget is removed Firefox 69.0.0 (Mac OS X 10.14.0) expected { Object (_flags, _layout, ...) } to equal { Object (_flags, _layout, ...) } AssertionError@build/bundle.test.js:21511:13 module.exports/Assertion.prototype.assert@build/bundle.test.js:39332:13 assertEqual@build/bundle.test.js:39849:12 module.exports/ctx[name]@build/bundle.test.js:43285:25 @build/bundle.test.js:31156:57 #activeWidget ✖ should be set to `null` when the active widget loses focus Firefox 69.0.0 (Mac OS X 10.14.0) expected { Object (_flags, _layout, ...) } to equal null AssertionError@build/bundle.test.js:21511:13 module.exports/Assertion.prototype.assert@build/bundle.test.js:39332:13 assertEqual@build/bundle.test.js:39849:12 module.exports/ctx[name]@build/bundle.test.js:43285:25 @build/bundle.test.js:31186:56 ✖ should be set to the widget that gained focus Firefox 69.0.0 (Mac OS X 10.14.0) expected { Object (_flags, _layout, ...) } to equal { Object (_flags, _layout, ...) } AssertionError@build/bundle.test.js:21511:13 module.exports/Assertion.prototype.assert@build/bundle.test.js:39332:13 assertEqual@build/bundle.test.js:39849:12 module.exports/ctx[name]@build/bundle.test.js:43285:25 @build/bundle.test.js:31197:56 #focusNumber() ✖ should give the highest number for the currentWidget Firefox 69.0.0 (Mac OS X 10.14.0) expected -1 to equal 1 AssertionError@build/bundle.test.js:21511:13 module.exports/Assertion.prototype.assert@build/bundle.test.js:39332:13 assertEqual@build/bundle.test.js:39849:12 module.exports/ctx[name]@build/bundle.test.js:43285:25 @build/bundle.test.js:31236:64 ✖ should update when a widget gains focus Firefox 69.0.0 (Mac OS X 10.14.0) expected 0 to equal 2 AssertionError@build/bundle.test.js:21511:13 module.exports/Assertion.prototype.assert@build/bundle.test.js:39332:13 assertEqual@build/bundle.test.js:39849:12 module.exports/ctx[name]@build/bundle.test.js:43285:25 @build/bundle.test.js:31257:64 #remove() ✖ should set the currentWidget to the previous one if the widget is the currentWidget Firefox 69.0.0 (Mac OS X 10.14.0) expected { Object (_flags, _layout, ...) } to equal { Object (_flags, _layout, ...) } AssertionError@build/bundle.test.js:21511:13 module.exports/Assertion.prototype.assert@build/bundle.test.js:39332:13 assertEqual@build/bundle.test.js:39849:12 module.exports/ctx[name]@build/bundle.test.js:43285:25 @build/bundle.test.js:31318:57 TabBar #tabMoved ✖ should be emitted when a tab is moved right by the user Firefox 69.0.0 (Mac OS X 10.14.0) Timeout of 2000ms exceeded. For async tests and hooks, ensure "done()" is called; if returning a Promise, ensure it resolves. ✖ should be emitted when a tab is moved left by the user Firefox 69.0.0 (Mac OS X 10.14.0) Timeout of 2000ms exceeded. For async tests and hooks, ensure "done()" is called; if returning a Promise, ensure it resolves. #tabActivateRequested ✖ should be emitted when a tab is left pressed by the user Firefox 69.0.0 (Mac OS X 10.14.0) expected false to equal true AssertionError@build/bundle.test.js:21511:13 module.exports/Assertion.prototype.assert@build/bundle.test.js:39332:13 assertEqual@build/bundle.test.js:39849:12 module.exports/ctx[name]@build/bundle.test.js:43285:25 @build/bundle.test.js:35414:42 ✖ should make the tab current and emit the `currentChanged` signal Firefox 69.0.0 (Mac OS X 10.14.0) expected 1 to equal 2 AssertionError@build/bundle.test.js:21511:13 module.exports/Assertion.prototype.assert@build/bundle.test.js:39332:13 assertEqual@build/bundle.test.js:39849:12 module.exports/ctx[name]@build/bundle.test.js:43285:25 @build/bundle.test.js:35424:52 ✖ should emit even if the pressed tab is the current tab Firefox 69.0.0 (Mac OS X 10.14.0) expected false to equal true AssertionError@build/bundle.test.js:21511:13 module.exports/Assertion.prototype.assert@build/bundle.test.js:39332:13 assertEqual@build/bundle.test.js:39849:12 module.exports/ctx[name]@build/bundle.test.js:43285:25 @build/bundle.test.js:35435:42 #tabCloseRequested ✖ should be emitted when a tab close icon is left clicked Firefox 69.0.0 (Mac OS X 10.14.0) expected false to equal true AssertionError@build/bundle.test.js:21511:13 module.exports/Assertion.prototype.assert@build/bundle.test.js:39332:13 assertEqual@build/bundle.test.js:39849:12 module.exports/ctx[name]@build/bundle.test.js:43285:25 @build/bundle.test.js:35458:42 ✖ should be emitted when a tab is middle clicked Firefox 69.0.0 (Mac OS X 10.14.0) expected false to equal true AssertionError@build/bundle.test.js:21511:13 module.exports/Assertion.prototype.assert@build/bundle.test.js:39332:13 assertEqual@build/bundle.test.js:39849:12 module.exports/ctx[name]@build/bundle.test.js:43285:25 @build/bundle.test.js:35471:42 #tabDetachRequested ✖ should be emitted when a tab is dragged beyond the detach threshold Firefox 69.0.0 (Mac OS X 10.14.0) expected false to equal true AssertionError@build/bundle.test.js:21511:13 module.exports/Assertion.prototype.assert@build/bundle.test.js:39332:13 assertEqual@build/bundle.test.js:39849:12 module.exports/ctx[name]@build/bundle.test.js:43285:25 @build/bundle.test.js:35512:42 ✖ should be handled by calling `releaseMouse` and removing the tab Firefox 69.0.0 (Mac OS X 10.14.0) expected false to equal true AssertionError@build/bundle.test.js:21511:13 module.exports/Assertion.prototype.assert@build/bundle.test.js:39332:13 assertEqual@build/bundle.test.js:39849:12 module.exports/ctx[name]@build/bundle.test.js:43285:25 @build/bundle.test.js:35524:42 ✖ should only be emitted once per drag cycle Firefox 69.0.0 (Mac OS X 10.14.0) expected 0 to equal 1 AssertionError@build/bundle.test.js:21511:13 module.exports/Assertion.prototype.assert@build/bundle.test.js:39332:13 assertEqual@build/bundle.test.js:39849:12 module.exports/ctx[name]@build/bundle.test.js:43285:25 @build/bundle.test.js:35536:42 ✖ should add the `p-mod-dragging` class to the tab and the bar Firefox 69.0.0 (Mac OS X 10.14.0) expected false to equal true AssertionError@build/bundle.test.js:21511:13 module.exports/Assertion.prototype.assert@build/bundle.test.js:39332:13 assertEqual@build/bundle.test.js:39849:12 module.exports/ctx[name]@build/bundle.test.js:43285:25 @build/bundle.test.js:35550:42 #allowDeselect ✖ should determine whether a tab can be deselected by the user Firefox 69.0.0 (Mac OS X 10.14.0) expected 2 to equal -1 AssertionError@build/bundle.test.js:21511:13 module.exports/Assertion.prototype.assert@build/bundle.test.js:39332:13 assertEqual@build/bundle.test.js:39849:12 module.exports/ctx[name]@build/bundle.test.js:43285:25 @build/bundle.test.js:35595:52 #handleEvent() left click ✖ should emit a tab close requested signal Firefox 69.0.0 (Mac OS X 10.14.0) expected false to equal true AssertionError@build/bundle.test.js:21511:13 module.exports/Assertion.prototype.assert@build/bundle.test.js:39332:13 assertEqual@build/bundle.test.js:39849:12 module.exports/ctx[name]@build/bundle.test.js:43285:25 @build/bundle.test.js:35968:46 middle click ✖ should emit a tab close requested signal Firefox 69.0.0 (Mac OS X 10.14.0) expected false to equal true AssertionError@build/bundle.test.js:21511:13 module.exports/Assertion.prototype.assert@build/bundle.test.js:39332:13 assertEqual@build/bundle.test.js:39849:12 module.exports/ctx[name]@build/bundle.test.js:43285:25 @build/bundle.test.js:36010:46 mousedown ✖ should add event listeners if the tabs are movable Firefox 69.0.0 (Mac OS X 10.14.0) expected -1 to not equal -1 AssertionError@build/bundle.test.js:21511:13 module.exports/Assertion.prototype.assert@build/bundle.test.js:39332:13 assertEqual@build/bundle.test.js:39849:12 module.exports/ctx[name]@build/bundle.test.js:43285:25 @build/bundle.test.js:36044:75 mousemove ✖ should do nothing if there is a drag in progress Firefox 69.0.0 (Mac OS X 10.14.0) expected 0 to equal 1 AssertionError@build/bundle.test.js:21511:13 module.exports/Assertion.prototype.assert@build/bundle.test.js:39332:13 assertEqual@build/bundle.test.js:39849:12 module.exports/ctx[name]@build/bundle.test.js:43285:25 @build/bundle.test.js:36084:46 ✖ should emit the detach requested signal if the threshold is exceeded Firefox 69.0.0 (Mac OS X 10.14.0) expected false to equal true AssertionError@build/bundle.test.js:21511:13 module.exports/Assertion.prototype.assert@build/bundle.test.js:39332:13 assertEqual@build/bundle.test.js:39849:12 module.exports/ctx[name]@build/bundle.test.js:43285:25 @build/bundle.test.js:36112:46 ✖ should bail if the signal handler aborted the drag Firefox 69.0.0 (Mac OS X 10.14.0) expected false to equal true AssertionError@build/bundle.test.js:21511:13 module.exports/Assertion.prototype.assert@build/bundle.test.js:39332:13 assertEqual@build/bundle.test.js:39849:12 module.exports/ctx[name]@build/bundle.test.js:43285:25 @build/bundle.test.js:36123:46 ✖ should update the positions of the tabs Firefox 69.0.0 (Mac OS X 10.14.0) expected false to equal true AssertionError@build/bundle.test.js:21511:13 module.exports/Assertion.prototype.assert@build/bundle.test.js:39332:13 assertEqual@build/bundle.test.js:39849:12 module.exports/ctx[name]@build/bundle.test.js:43285:25 @build/bundle.test.js:36134:46 mouseup ✖ should emit the `tabMoved` signal Firefox 69.0.0 (Mac OS X 10.14.0) Timeout of 2000ms exceeded. For async tests and hooks, ensure "done()" is called; if returning a Promise, ensure it resolves. ✖ should move the tab to its final position Firefox 69.0.0 (Mac OS X 10.14.0) Timeout of 2000ms exceeded. For async tests and hooks, ensure "done()" is called; if returning a Promise, ensure it resolves. ✖ should cancel a middle mouse release Firefox 69.0.0 (Mac OS X 10.14.0) expected false to equal true AssertionError@build/bundle.test.js:21511:13 module.exports/Assertion.prototype.assert@build/bundle.test.js:39332:13 assertEqual@build/bundle.test.js:39849:12 module.exports/ctx[name]@build/bundle.test.js:43285:25 @build/bundle.test.js:36159:49 keydown ✖ should prevent default Firefox 69.0.0 (Mac OS X 10.14.0) expected false to equal true AssertionError@build/bundle.test.js:21511:13 module.exports/Assertion.prototype.assert@build/bundle.test.js:39332:13 assertEqual@build/bundle.test.js:39849:12 module.exports/ctx[name]@build/bundle.test.js:43285:25 @build/bundle.test.js:36167:49 contextmenu ✖ should prevent default Firefox 69.0.0 (Mac OS X 10.14.0) expected false to equal true AssertionError@build/bundle.test.js:21511:13 module.exports/Assertion.prototype.assert@build/bundle.test.js:39332:13 assertEqual@build/bundle.test.js:39849:12 module.exports/ctx[name]@build/bundle.test.js:43285:25 @build/bundle.test.js:36181:49

phosphorjs / phosphor

Some FocusTracker and TabBar unittests fail in master on OS X with latest Firefox #441