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Test Info: Warnings
- This test has a WPT meta file that expects 1 subtest issues.
- This WPT test may be referenced by the following Test IDs:
- /fetch/api/response/response-body-read-task-handling.html - WPT Dashboard Interop Dashboard
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title></title>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
</head>
<body>
<script>
function performMicrotaskCheckpoint() {
document.createNodeIterator(document, -1, {
acceptNode() {
return NodeFilter.FILTER_ACCEPT;
}
}).nextNode();
}
promise_test(function() {
return fetch("../resources/data.json").then(function(response) {
// Add a getter for "then" that will incidentally be invoked
// during promise resolution.
Object.prototype.__defineGetter__('then', () => {
// Clean up behind ourselves.
delete Object.prototype.then;
// This promise should (like all promises) be resolved
// asynchronously.
var executed = false;
Promise.resolve().then(_ => { executed = true; });
// This shouldn't run microtasks! They should only run
// after the fetch is resolved.
performMicrotaskCheckpoint();
// The fulfill handler above shouldn't have run yet. If it has run,
// throw to reject this promise and fail the test.
assert_false(executed, "shouldn't have run microtasks yet");
// Otherwise act as if there's no "then" property so the promise
// fulfills and the test passes.
return undefined;
});
// Create a read request, incidentally resolving a promise with an
// object value, thereby invoking the getter installed above.
return response.body.getReader().read();
});
}, "reading from a body stream should occur in a microtask scope");
promise_test(function() {
return fetch("../resources/data.json").then(function(response) {
// Add a getter for "then" that will incidentally be invoked
// during promise resolution.
Object.prototype.__defineGetter__('then', () => {
// Clean up behind ourselves.
delete Object.prototype.then;
// This promise should (like all promises) be resolved
// asynchronously.
var executed = false;
Promise.resolve().then(_ => { executed = true; });
// This shouldn't run microtasks! They should only run
// after the fetch is resolved.
performMicrotaskCheckpoint();
// The fulfill handler above shouldn't have run yet. If it has run,
// throw to reject this promise and fail the test.
assert_false(executed, "shouldn't have run microtasks yet");
// Otherwise act as if there's no "then" property so the promise
// fulfills and the test passes.
return undefined;
});
// Create a read request, incidentally resolving a promise with an
// object value, thereby invoking the getter installed above.
return response.body.pipeTo(new WritableStream({
write(chunk) {}
}))
});
}, "piping from a body stream to a JS-written WritableStream should occur in a microtask scope");
</script>
</body>
</html>