forked from mirrors/gecko-dev
809beee368
*** Bug 1682898 Migrate Performance Best Practices for Front-end Engineers MDN page to in-tree docs *** Bug 1682898 Migrate Performance Best Practices for Front-end Engineers MDN page to in-tree docs Differential Revision: https://phabricator.services.mozilla.com/D109970
99 lines
3.1 KiB
JavaScript
99 lines
3.1 KiB
JavaScript
"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();
|
|
});
|