function test() { waitForExplicitFinish(); let tab = gBrowser.addTab("http://example.com"); tab.linkedBrowser.addEventListener('load', function() { let numLocationChanges = 0; let listener = { onLocationChange: function() { numLocationChanges++; } }; gBrowser.addTabsProgressListener(listener); // pushState to a new URL (http://example.com/foo"). This should trigger // exactly one LocationChange event. tab.linkedBrowser.contentWindow.history.pushState(null, null, "foo"); executeSoon(function() { gBrowser.removeTab(tab); gBrowser.removeTabsProgressListener(listener); is(numLocationChanges, 1, "pushState should cause exactly one LocationChange event."); finish(); }); }, true); }