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Test Info:
- This WPT test may be referenced by the following Test IDs:
- /dom/events/scrolling/wheel-event-transactions-target-removal.html - WPT Dashboard Interop Dashboard
<!DOCTYPE HTML>
<html>
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width,initial-scale=1,minimum-scale=1">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="/resources/testdriver.js"></script>
<script src="/resources/testdriver-actions.js"></script>
<script src="/resources/testdriver-vendor.js"></script>
<script src="scroll_support.js"></script>
<style>
body {
margin: 0;
padding: 0;
height: 200vh;
}
.spacer {
width: 100%;
height: 25px;
padding: 0;
margin: 0;
}
</style>
<head>
<body>
<div id="initialTarget" class="spacer" style="background: red"></div>
<div id="firstRootSpacer" class="spacer" style="background: green"></div>
<div id="secondRootSpacer" class="spacer" style="background: blue"></div>
</body>
<script>
promise_test(async (t) => {
await new Promise(resolve => addEventListener("load", resolve, {once: true}));
await waitForCompositorReady();
await waitForCompositorCommit();
let initialTarget = null;
let wheelEventTargets = [];
let removedInitialTarget = false;
// Remove the initial element the wheel event is targetted at once we fire the
// first wheel event, then log the subsequent wheel event targets.
function removeInitialElement(e) {
wheelEventTargets.push(e.target);
if (!removedInitialTarget) {
initialTarget = e.target;
e.target.remove();
removedInitialTarget = true;
initialTarget.addEventListener("wheel", () => {
assert_true(false, "wheel event should never be fired after the target is removed")
}, {passive: true});
}
}
window.addEventListener("wheel", removeInitialElement, {passive: true});
await waitForCompositorCommit();
await new test_driver.Actions()
.addWheel("wheel1")
.scroll(40, 2, 0, 30, {origin: "viewport"})
.pause(1)
.scroll(40, 2, 0, 30, {origin: "viewport"})
.send();
// TODO(dlrobertson): Use the scrollend event here to wait for the
// wheel scroll to finish instead of waitForAnimationEnd().
await waitForAnimationEnd(() => { return document.scrollingElement.scrollTop; });
await waitForCompositorCommit();
assert_true(removedInitialTarget, "Removed the initial target");
// The first wheel event should be targetted at the removed element.
assert_equals(wheelEventTargets.shift(), initialTarget,
"Initial wheel event has the removed element as the target");
wheelEventTargets.forEach((wheelEventTarget, i) => {
// TODO(dlrobertson): This assertion is pretty weak, but browsers seem to disagree
// on what element the event should target. Find out what the target should be here
// and make this assertion more restrictive.
assert_not_equals(wheelEventTarget, initialTarget,
"Wheel event at index `" + i + "` targetted the initial element");
});
assert_greater_than(document.scrollingElement.scrollTop, 0, "The document has scrolled");
}, "Remove the initial wheel event target.");
</script>
</html>