image-decode-with-quick-attach.html

<!DOCTYPE html>
<meta charset=utf-8>
<meta name="timeout" content="long">
<title>HTMLImageElement.prototype.decode(), attach to DOM before promise resolves.</title>
<link rel="author" title="Vladimir Levin" href="mailto:[email protected]">
<link rel=help href="https://html.spec.whatwg.org/multipage/embedded-content.html#dom-img-decode">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>

<body>
  <picture id="empty-picture-1"></picture>
  <picture id="empty-picture-2"></picture>
  <picture id="empty-picture-3"></picture>
  <picture id="picture-with-source-1">
    <source srcset="/images/blue.png"></source>
  </picture>
  <picture id="picture-with-source-2">
    <source srcset="/images/blue.png"></source>
  </picture>
  <picture id="picture-with-source-3">
    <source srcset="/images/blue.png"></source>
  </picture>
</body>

<script>
"use strict";

let png = "/images/green.png?image-decode-with-quick-attach-" + Math.random();

function run_test(t, {
  image = png,
  prop = "src",
  container = document.body,
  expectReject = false
} = {}) {
  const img = new Image();
  img[prop] = image;
  const promise = img.decode().then(function (arg) {
    assert_equals(arg, undefined);
  });
  // Intentionally don't wait for the promise to settle before attaching the image.
  container.appendChild(img);
  return expectReject ?
    promise_rejects_dom(t, "EncodingError", promise) :
    promise;
}

promise_test(t => run_test(t), document.title + ": src not cached");
promise_test(t => run_test(t), document.title + ": src cached");
promise_test(t => run_test(t, {prop: "srcset"}), document.title + ": srcset");
promise_test(t => run_test(t, {
  image: png + "-picture",
  container: document.getElementById("empty-picture-1"),
  expectReject: true,
}), document.title + ": src in empty picture not cached");
promise_test(t => run_test(t, {
  image: png + "-picture",
  container: document.getElementById("empty-picture-2"),
  // NOTE(emilio): This is inconsistent between the cached and un-cached case
  // below, but actually correct per spec, because in the sync case the current
  // request doesn't mutate after the decode() call.
  // This is expected to change in https://github.com/whatwg/html/issues/10531
  expectReject: false,
}), document.title + ": src in empty picture cached");
promise_test(t => run_test(t, {
  image: png + "-picture-srcset",
  prop: "srcset",
  container: document.getElementById("empty-picture-3"),
  expectReject: true,
}), document.title + ": srcset in empty picture");
promise_test(t => run_test(t, {
  image: png + "-picture-with-source",
  container: document.getElementById("picture-with-source-1"),
  expectReject: true,
}), document.title + ": src in picture with source not cached");
promise_test(t => run_test(t, {
  image: png + "-picture-with-source",
  container: document.getElementById("picture-with-source-2"),
  expectReject: true,
}), document.title + ": src in picture with source cached");
promise_test(t => run_test(t, {
  image: png + "-picture-with-source-srcset",
  prop: "srcset",
  container: document.getElementById("picture-with-source-3"),
  expectReject: true,
}), document.title + ": srcset in picture with source");
</script>
chromium/third_party/blink/web_tests/external/wpt/html/semantics/embedded-content/the-img-element/decode/image-decode-with-quick-attach.html
