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Test Info: Warnings
- This test gets skipped with pattern: os == 'win' && verify && !debug OR win11_2009 && bits == 32
- Manifest: browser/base/content/test/performance/browser.toml
"use strict";
/**
* WHOA THERE: We should never be adding new things to EXPECTED_*_REFLOWS.
* This is a (now empty) list of known reflows.
* Instead of adding more reflows to the lists, you should be modifying your
* code to avoid the reflow.
*
* for tips on how to do that.
*/
const EXPECTED_OVERFLOW_REFLOWS = [
/**
* Nothing here! Please don't add anything new!
*/
];
const EXPECTED_UNDERFLOW_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 overflow and the tab
* strip to become scrollable. It also tests that there are no unexpected
* uninterruptible reflows when closing that tab, which causes the tab strip to
* underflow.
*/
add_task(async function () {
// Force-enable tab animations
gReduceMotionOverride = false;
await ensureNoPreloadedBrowser();
// 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"]],
});
const TAB_COUNT_FOR_OVERFLOW = computeMaxTabCount();
await createTabs(TAB_COUNT_FOR_OVERFLOW);
gURLBar.focus();
await disableFxaBadge();
let tabStripRect =
gBrowser.tabContainer.arrowScrollbox.getBoundingClientRect();
let textBoxRect = gURLBar
.querySelector("moz-input-box")
.getBoundingClientRect();
let ignoreTabstripRects = {
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
)
)
),
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,
},
{
condition: r =>
// In the content area
r.y1 >=
document.getElementById("tabbrowser-tabbox").getBoundingClientRect()
.top,
},
],
};
await withPerfObserver(
async function () {
let switchDone = BrowserTestUtils.waitForEvent(window, "TabSwitchDone");
BrowserCommands.openTab();
await BrowserTestUtils.waitForEvent(
gBrowser.selectedTab,
"TabAnimationEnd"
);
await switchDone;
await TestUtils.waitForCondition(() => {
return gBrowser.tabContainer.arrowScrollbox.hasAttribute(
"scrolledtoend"
);
});
},
{ expectedReflows: EXPECTED_OVERFLOW_REFLOWS, frames: ignoreTabstripRects }
);
Assert.ok(
gBrowser.tabContainer.overflowing,
"Tabs should now be overflowed."
);
// Now test that opening and closing a tab while overflowed doesn't cause
// us to reflow.
await withPerfObserver(
async function () {
let switchDone = BrowserTestUtils.waitForEvent(window, "TabSwitchDone");
BrowserCommands.openTab();
await switchDone;
await TestUtils.waitForCondition(() => {
return gBrowser.tabContainer.arrowScrollbox.hasAttribute(
"scrolledtoend"
);
});
},
{ expectedReflows: [], frames: ignoreTabstripRects }
);
await withPerfObserver(
async function () {
let switchDone = BrowserTestUtils.waitForEvent(window, "TabSwitchDone");
BrowserTestUtils.removeTab(gBrowser.selectedTab, { animate: true });
await switchDone;
},
{ expectedReflows: [], frames: ignoreTabstripRects }
);
// At this point, we have an overflowed tab strip, and we've got the last tab
// selected. This should mean that the first tab is scrolled out of view.
// Let's test that we don't reflow when switching to that first tab.
let lastTab = gBrowser.selectedTab;
let arrowScrollbox = gBrowser.tabContainer.arrowScrollbox;
// First, we'll check that the first tab is actually scrolled
// at least partially out of view.
Assert.ok(
arrowScrollbox.scrollPosition > 0,
"First tab should be partially scrolled out of view."
);
// Now switch to the first tab. We shouldn't flush layout at all.
await withPerfObserver(
async function () {
let firstTab = gBrowser.tabs[0];
await BrowserTestUtils.switchTab(gBrowser, firstTab);
await TestUtils.waitForCondition(() => {
return gBrowser.tabContainer.arrowScrollbox.hasAttribute(
"scrolledtostart"
);
});
},
{ expectedReflows: [], frames: ignoreTabstripRects }
);
// Okay, now close the last tab. The tabstrip should stay overflowed, but removing
// one more after that should underflow it.
BrowserTestUtils.removeTab(lastTab);
Assert.ok(
gBrowser.tabContainer.overflowing,
"Tabs should still be overflowed."
);
// Depending on the size of the window, it might take one or more tab
// removals to put the tab strip out of the overflow state, so we'll just
// keep testing removals until that occurs.
while (gBrowser.tabContainer.overflowing) {
lastTab = gBrowser.tabs.at(-1);
if (gBrowser.selectedTab !== lastTab) {
await BrowserTestUtils.switchTab(gBrowser, lastTab);
}
// ... and make sure we don't flush layout when closing it, and exiting
// the overflowed state.
await withPerfObserver(
async function () {
let switchDone = BrowserTestUtils.waitForEvent(window, "TabSwitchDone");
BrowserTestUtils.removeTab(lastTab, { animate: true });
await switchDone;
await TestUtils.waitForCondition(() => !lastTab.isConnected);
},
{
expectedReflows: EXPECTED_UNDERFLOW_REFLOWS,
frames: ignoreTabstripRects,
}
);
}
await removeAllButFirstTab();
});