add_task(async function() { // We don't want the number of total viewers to be calculated by the available size // for this test case. Instead, fix the number of viewers. await SpecialPowers.pushPrefEnv({ set: [ ["browser.sessionhistory.max_total_viewers", 3], ["docshell.shistory.testing.bfevict", true], ], }); // 1. Open a tab var testPage = "data:text/html,First tab ever opened"; await BrowserTestUtils.withNewTab({ gBrowser, url: testPage }, async function( browser ) { let testDone = {}; if (!SpecialPowers.Services.appinfo.sessionHistoryInParent) { // 2. Add a promise that will be resolved when the 'content viewer evicted' event goes off testDone.promise = SpecialPowers.spawn(browser, [], async function() { return new Promise(resolve => { let webNavigation = content.docShell.QueryInterface( Ci.nsIWebNavigation ); let { legacySHistory } = webNavigation.sessionHistory; // 3. Register a session history listener to listen for a 'content viewer evicted' event. let historyListener = { OnContentViewerEvicted() { ok( true, "History listener got called after a content viewer was evicted" ); legacySHistory.removeSHistoryListener(historyListener); // 6. Resolve the promise when we got our 'content viewer evicted' event resolve(); }, QueryInterface: ChromeUtils.generateQI([ "nsISHistoryListener", "nsISupportsWeakReference", ]), }; legacySHistory.addSHistoryListener(historyListener); // Keep the weak shistory listener alive content._testListener = historyListener; }); }); } else { // 2. Add a promise that will be resolved when the 'content viewer evicted' event goes off testDone.promise = new Promise(resolve => { testDone.resolve = resolve; }); let shistory = browser.browsingContext.sessionHistory; // 3. Register a session history listener to listen for a 'content viewer evicted' event. let historyListener = { OnContentViewerEvicted() { ok( true, "History listener got called after a content viewer was evicted" ); shistory.removeSHistoryListener(historyListener); delete window._testListener; // 6. Resolve the promise when we got our 'content viewer evicted' event testDone.resolve(); }, QueryInterface: ChromeUtils.generateQI([ "nsISHistoryListener", "nsISupportsWeakReference", ]), }; shistory.addSHistoryListener(historyListener); // Keep the weak shistory listener alive window._testListener = historyListener; } // 4. Open a second tab testPage = `data:text/html,I am a second tab!`; let tab2 = await BrowserTestUtils.openNewForegroundTab(gBrowser, testPage); // 5. Navigate the first tab to 4 different pages. // We should get 1 content viewer evicted because it will be outside of the range. // If we have the following pages in our session history: P1 P2 P3 P4 P5 // and we are currently at P5, then P1 is outside of the range // (it is more than 3 entries away from current entry) and thus will be evicted. for (var i = 0; i < 4; i++) { testPage = `data:text/html,${i}`; let pagePromise = BrowserTestUtils.browserLoaded(browser); BrowserTestUtils.loadURI(browser, testPage); await pagePromise; } // 7. Wait for 'content viewer evicted' event to go off await testDone.promise; // 8. Close the second tab BrowserTestUtils.removeTab(tab2); }); });