https://treeherder.mozilla.org/#/jobs?repo=try&revision=a256f95712e8844d888ec18891822e949bc85c6d&selectedJob=143961950 > FAIL | browser/components/sessionstore/test/browser_async_remove_tab.js | Found an unexpected tab at the end of test run: jar:file:///builds/worker/workspace/build/application/firefox/browser/omni.ja!/chrome/browser/content/browser/aboutRobots.xhtml It waits for OnHistoryReplaceEntry, and removes the tab, but when the OnHistoryReplaceEntry is called, the tab is not ready for removing, and promiseRemoveTab(tab) doesn't remove the tab. that results in leaving the tab opened. the test should wait for the tab to get ready before resolving promise in OnHistoryReplaceEntry.

similar to other promise related tests, this also needs to wait for the next event tick.

(In reply to Tooru Fujisawa [:arai] from comment #0) > https://treeherder.mozilla.org/#/ > jobs?repo=try&revision=a256f95712e8844d888ec18891822e949bc85c6d&selectedJob=1 > 43961950 > > FAIL | browser/components/sessionstore/test/browser_async_remove_tab.js | Found an unexpected tab at the end of test run: jar:file:///builds/worker/workspace/build/application/firefox/browser/omni.ja!/chrome/browser/content/browser/aboutRobots.xhtml > > It waits for OnHistoryReplaceEntry, and removes the tab, but when the > OnHistoryReplaceEntry is called, the tab is not ready for removing, and > promiseRemoveTab(tab) doesn't remove the tab. that results in leaving the > tab opened. > > the test should wait for the tab to get ready before resolving promise in > OnHistoryReplaceEntry. What about the tab isn't ready?

Comment on attachment 8929346 [details] [diff] [review] Wait for the next event tick before resolving Promise for history event in browser/components/sessionstore/test/browser_async_remove_tab.js Review of attachment 8929346 [details] [diff] [review]: ----------------------------------------------------------------- Let's see how this does in automation.

https://hg.mozilla.org/integration/mozilla-inbound/rev/280e6695b89da9da70db5ecc0d97aac064306d2f Bug 1418183 - Wait for the next event tick before resolving Promise for history event in browser/components/sessionstore/test/browser_async_remove_tab.js r=mossop