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Diffstat (limited to '')
-rw-r--r-- | browser/base/content/test/performance/browser_tabopen_squeeze.js | 100 |
1 files changed, 100 insertions, 0 deletions
diff --git a/browser/base/content/test/performance/browser_tabopen_squeeze.js b/browser/base/content/test/performance/browser_tabopen_squeeze.js new file mode 100644 index 0000000000..f92bdc2ea4 --- /dev/null +++ b/browser/base/content/test/performance/browser_tabopen_squeeze.js @@ -0,0 +1,100 @@ +"use strict"; + +/** + * WHOA THERE: We should never be adding new things to EXPECTED_REFLOWS. + * Instead of adding reflows to the list, you should be modifying your code to + * avoid the reflow. + * + * See https://firefox-source-docs.mozilla.org/performance/bestpractices.html + * for tips on how to do that. + */ +const EXPECTED_REFLOWS = [ + /** + * Nothing here! Please don't add anything new! + */ +]; + +/* + * This test ensures that there are no unexpected + * uninterruptible reflows when opening a new tab that will + * cause the existing tabs to squeeze smaller. + */ +add_task(async function () { + // Force-enable tab animations + gReduceMotionOverride = false; + + await ensureNoPreloadedBrowser(); + await disableFxaBadge(); + + // The test starts on about:blank and opens an about:blank + // tab which triggers opening the toolbar since + // ensureNoPreloadedBrowser sets AboutNewTab.newTabURL to about:blank. + await SpecialPowers.pushPrefEnv({ + set: [["browser.toolbars.bookmarks.visibility", "never"]], + }); + + // Compute the number of tabs we can put into the strip without + // overflowing, and remove one, so that we can create + // TAB_COUNT_FOR_SQUEEE tabs, and then one more, which should + // cause the tab to squeeze to a smaller size rather than overflow. + const TAB_COUNT_FOR_SQUEEZE = computeMaxTabCount() - 1; + + await createTabs(TAB_COUNT_FOR_SQUEEZE); + + gURLBar.focus(); + + let tabStripRect = + gBrowser.tabContainer.arrowScrollbox.getBoundingClientRect(); + let textBoxRect = gURLBar + .querySelector("moz-input-box") + .getBoundingClientRect(); + + await withPerfObserver( + async function () { + let switchDone = BrowserTestUtils.waitForEvent(window, "TabSwitchDone"); + BrowserOpenTab(); + await BrowserTestUtils.waitForEvent( + gBrowser.selectedTab, + "TabAnimationEnd" + ); + await switchDone; + }, + { + expectedReflows: EXPECTED_REFLOWS, + frames: { + filter: rects => + rects.filter( + r => + !( + // We expect plenty of changed rects within the tab strip. + ( + r.y1 >= tabStripRect.top && + r.y2 <= tabStripRect.bottom && + r.x1 >= tabStripRect.left && + r.x2 <= tabStripRect.right && + // It would make sense for each rect to have a width smaller than + // a tab (ie. tabstrip.width / tabcount), but tabs are small enough + // that they sometimes get reported in the same rect. + // So we accept up to the width of n-1 tabs. + r.w <= + (gBrowser.tabs.length - 1) * + Math.ceil(tabStripRect.width / gBrowser.tabs.length) + ) + ) + ), + exceptions: [ + { + name: "the urlbar placeolder moves up and down by a few pixels", + condition: r => + r.x1 >= textBoxRect.left && + r.x2 <= textBoxRect.right && + r.y1 >= textBoxRect.top && + r.y2 <= textBoxRect.bottom, + }, + ], + }, + } + ); + + await removeAllButFirstTab(); +}); |