list-of-available-images-does-not-coalesce-in-flight-requests.sub.tentative.html

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This test has a WPT meta file that expects 1 subtest issues.
This WPT test may be referenced by the following Test IDs:
- /html/semantics/embedded-content/the-img-element/list-of-available-images-does-not-coalesce-in-flight-requests.sub.tentative.html - WPT Dashboard Interop Dashboard

<!doctype html>

<html>

<title>List of available images does not coalesce in-flight requests</title>

<link rel="author" title="Dom Farolino" href="mailto:dom@chromium.org">

<link rel="help" href="https://html.spec.whatwg.org/multipage/#the-list-of-available-images">

<script src="/resources/testharness.js"></script>

<script src="/resources/testharnessreport.js"></script>

<script>

const uuid = "{{uuid()}}";

const path = location.origin + '/html/semantics/embedded-content/the-img-element/resources/image-and-stash.py';

promise_test(async t => {

  let first_image_promise = new Promise((resolve, reject) => {

    const img = new Image();

    img.onload = resolve;

    img.onerror = e => { reject(new Error("The img should not fail to load")) };

    img.src = path + `?increment=${uuid}&pipe=trickle(d1)`;

});

  // As of right now, the spec's #updating-the-image-data step 6 [1] does not

  // place images into the "list of available images" until they are completely

  // downloaded and the `load` event is fired. The spec also explicitly states

  // that coalescing in-flight image requests is not what the list of available

  // images is for. This test asserts this behavior, though since no browsers

  // follow this behavior (they all allow coalescing in-flight requests for the

  // same image resource) we've started discussion about this in

  // https://github.com/whatwg/html/issues/7005. If that issue resolves in

  // letting in-flight requests into the list of available images, then we

  // should changes the expectations of this test.

//

  // [1]: https://html.spec.whatwg.org/multipage/images.html#updating-the-image-data

  let second_image_promise = new Promise((resolve, reject) => {

    const img = new Image();

    img.onload = resolve;

    img.onerror = e => { reject("The img should not fail to load") };

    img.src = path + `?increment=${uuid}&pipe=trickle(d1)`;

});

  await Promise.all([first_image_promise, second_image_promise]);

  const response = await fetch(path + `?read=${uuid}`);

  const request_count = await response.text();

  assert_equals(request_count, "2", "The server should have seen exactly two " +

                                    "requests, since the second image request " +

                                    "above did not coalesce with the first " +

                                    "in-flight one");

}, 'list of available images does not coalesce in-flight requests');

</script>