Intermitent Java_Errors in console during test-Controller:test_StopAndStart

[mzhilyaev]

When running all unit-tests, I observe intermittent errors displayed on console during test-Controller:test_StopAndStart. All tests are still passing though.

executing 'firefox-personalization-study/tests/test-Controller.test stop and start'

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• Call to xpconnect wrapped JSObject produced this error: * [Exception... "'[JavaScript Error: "storage.interests is not an object" {file: "resource://gre/modules/XPIProvider.jsm -> jar:file:///var/folders/5c/qfsq525n1k546rcjv10p333m0000gn/T/tmp3giCZU.mozrunner/extensions/firefox.personalization.study@up.mozilla.xpi!/bootstrap.js -> resource://gre/modules/commonjs/toolkit/loader.js -> resource://firefox-dot-personalization-dot-study-at-up-dot-mozilla/firefox-personalization-study/lib/Dispatcher.js" line: 119}]' when calling method: [nsIObserver::observe]" nsresult: "0x80570021 (NS_ERROR_XPC_JAVASCRIPT_ERROR_WITH_DETAILS)" location: "native frame :: :: :: line 0" data: yes]

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[mzhilyaev]

• moved away test-Ranking and test-Dispatcher, and then moved these files back into test directory: no longer can reproduce
• updated to the latest master: no longer can reproduce

I suspect that this error condition depends on the order of test file execution, but i just can't reproduce it any more. I believe these are test hardness artifacts and we should not spend much time on it.