LibWeb: Resolve FIXME in media select resource algorithm

Fixes at least three WPT test that were previously timing out:
- html/semantics/embedded-content/media-elements/error-codes/error.html
- html/semantics/embedded-content/media-elements/location-of-the-media-resource/currentSrc.html
- html/semantics/embedded-content/the-video-element/video_crash_empty_src.html

Libraries/LibWeb/HTML/HTMLMediaElement.cpp

@@ -40,6 +40,7 @@
 #include <LibWeb/MimeSniff/MimeType.h>
 #include <LibWeb/Page/Page.h>
 #include <LibWeb/Painting/Paintable.h>
+#include <LibWeb/Platform/EventLoopPlugin.h>
 #include <LibWeb/WebIDL/Promise.h>
 
 namespace Web::HTML {
@@ -813,9 +814,10 @@ WebIDL::ExceptionOr<void> HTMLMediaElement::select_resource()
     // 3. Set the media element's delaying-the-load-event flag to true (this delays the load event).
     m_delaying_the_load_event.emplace(document());
 
-    // FIXME: 4. Await a stable state, allowing the task that invoked this algorithm to continue. The synchronous section consists of all the remaining
+    // 4. Await a stable state, allowing the task that invoked this algorithm to continue. The synchronous section consists of all the remaining
     // steps of this algorithm until the algorithm says the synchronous section has ended. (Steps in synchronous sections are marked with ⌛.)
 
+    queue_a_microtask(&document(), GC::create_function(realm.heap(), [this, &realm]() {
         // FIXME: 5. ⌛ If the media element's blocked-on-parser flag is false, then populate the list of pending text tracks.
 
         Optional<SelectMode> mode;
@@ -842,7 +844,7 @@ WebIDL::ExceptionOr<void> HTMLMediaElement::select_resource()
             m_delaying_the_load_event.clear();
 
             // 3. End the synchronous section and return.
-        return {};
+            return;
         }
 
         // 7. ⌛ Set the media element's networkState to NETWORK_LOADING.
@@ -866,7 +868,7 @@ WebIDL::ExceptionOr<void> HTMLMediaElement::select_resource()
             // FIXME: 5. Wait for the task queued by the previous step to have executed.
 
             // 6. Return. The element won't attempt to load another resource until this algorithm is triggered again.
-        return {};
+            return;
 
         // -> If mode is attribute
         case SelectMode::Attribute: {
@@ -890,7 +892,7 @@ WebIDL::ExceptionOr<void> HTMLMediaElement::select_resource()
             auto source = get_attribute_value(HTML::AttributeNames::src);
             if (source.is_empty()) {
                 failed_with_attribute("The 'src' attribute is empty"_string);
-            return {};
+                return;
             }
 
             // 2. ⌛ Let urlString and urlRecord be the resulting URL string and the resulting URL record, respectively, that would have resulted from parsing
@@ -905,15 +907,15 @@ WebIDL::ExceptionOr<void> HTMLMediaElement::select_resource()
 
             // 5. If urlRecord was obtained successfully, run the resource fetch algorithm with urlRecord. If that algorithm returns without aborting this one,
             //    then the load failed.
+            Platform::EventLoopPlugin::the().deferred_invoke(GC::create_function(realm.heap(), [this, url_record = move(url_record), failed_with_attribute = move(failed_with_attribute)]() mutable {
                 if (url_record.has_value()) {
-            TRY(fetch_resource(*url_record, move(failed_with_attribute)));
-            return {};
+                    fetch_resource(*url_record, move(failed_with_attribute)).release_value_but_fixme_should_propagate_errors();
+                    return;
                 }
-
-        failed_with_attribute("Failed to parse 'src' attribute as a URL"_string);
+            }));
 
             // 8. Return. The element won't attempt to load another resource until this algorithm is triggered again.
-        return {};
+            return;
         }
 
         // -> Otherwise (mode is children)
@@ -941,10 +943,11 @@ WebIDL::ExceptionOr<void> HTMLMediaElement::select_resource()
             //       with the headache of auto-updating this pointer as the DOM changes.
 
             m_source_element_selector = realm.create<SourceElementSelector>(*this, *candidate);
-        TRY(m_source_element_selector->process_candidate());
+            m_source_element_selector->process_candidate().release_value_but_fixme_should_propagate_errors();
 
             break;
         }
+    }));
 
     return {};
 }

Tests/LibWeb/Text/expected/wpt-import/html/semantics/embedded-content/media-elements/error-codes/error.txt

@@ -0,0 +1,12 @@
+Harness status: OK
+
+Found 6 tests
+
+4 Pass
+2 Fail
+Pass	audio.error initial value
+Fail	audio.error after successful load
+Pass	audio.error after setting src to the empty string
+Pass	video.error initial value
+Fail	video.error after successful load
+Pass	video.error after setting src to the empty string

Tests/LibWeb/Text/expected/wpt-import/html/semantics/embedded-content/media-elements/location-of-the-media-resource/currentSrc.txt

@@ -0,0 +1,23 @@
+Harness status: OK
+
+Found 18 tests
+
+18 Pass
+Pass	audio.currentSrc initial value
+Pass	audio.currentSrc after setting src attribute ""
+Pass	audio.currentSrc after adding source element with src attribute ""
+Pass	audio.currentSrc after setting src attribute "."
+Pass	audio.currentSrc after adding source element with src attribute "."
+Pass	audio.currentSrc after setting src attribute " "
+Pass	audio.currentSrc after adding source element with src attribute " "
+Pass	audio.currentSrc after setting src attribute "data:,"
+Pass	audio.currentSrc after adding source element with src attribute "data:,"
+Pass	video.currentSrc initial value
+Pass	video.currentSrc after setting src attribute ""
+Pass	video.currentSrc after adding source element with src attribute ""
+Pass	video.currentSrc after setting src attribute "."
+Pass	video.currentSrc after adding source element with src attribute "."
+Pass	video.currentSrc after setting src attribute " "
+Pass	video.currentSrc after adding source element with src attribute " "
+Pass	video.currentSrc after setting src attribute "data:,"
+Pass	video.currentSrc after adding source element with src attribute "data:,"

Tests/LibWeb/Text/expected/wpt-import/html/semantics/embedded-content/the-video-element/video_crash_empty_src.txt

@@ -0,0 +1,7 @@
+Harness status: OK
+
+Found 2 tests
+
+2 Pass
+Pass	src="about:blank" does not crash.
+Pass	src="" does not crash.

Tests/LibWeb/Text/input/wpt-import/common/media.js

@@ -0,0 +1,57 @@
+/**
+ * Returns the URL of a supported video source based on the user agent
+ * @param {string} base - media URL without file extension
+ * @returns {string}
+ */
+function getVideoURI(base)
+{
+    var extension = '.mp4';
+
+    var videotag = document.createElement("video");
+
+    if ( videotag.canPlayType )
+    {
+      if (videotag.canPlayType('video/webm; codecs="vp9, opus"') )
+      {
+          extension = '.webm';
+      }
+    }
+
+    return base + extension;
+}
+
+/**
+ * Returns the URL of a supported audio source based on the user agent
+ * @param {string} base - media URL without file extension
+ * @returns {string}
+ */
+function getAudioURI(base)
+{
+    var extension = '.mp3';
+
+    var audiotag = document.createElement("audio");
+
+    if ( audiotag.canPlayType &&
+         audiotag.canPlayType('audio/ogg') )
+    {
+        extension = '.oga';
+    }
+
+    return base + extension;
+}
+
+/**
+ * Returns the MIME type for a media URL based on the file extension.
+ * @param {string} url
+ * @returns {string}
+ */
+function getMediaContentType(url) {
+    var extension = new URL(url, location).pathname.split(".").pop();
+    var map = {
+        "mp4" : "video/mp4",
+        "webm": "video/webm",
+        "mp3" : "audio/mp3",
+        "oga" : "application/ogg",
+    };
+    return map[extension];
+}

Tests/LibWeb/Text/input/wpt-import/html/semantics/embedded-content/media-elements/error-codes/error.html

@@ -0,0 +1,40 @@
+<!doctype html>
+<title>error</title>
+<script src="../../../../../resources/testharness.js"></script>
+<script src="../../../../../resources/testharnessreport.js"></script>
+<script src="../../../../../common/media.js"></script>
+<div id="log"></div>
+<script>
+function error_test(tagName, src) {
+  test(function() {
+    assert_equals(document.createElement(tagName).error, null);
+  }, tagName + '.error initial value');
+
+  async_test(function(t) {
+    var e = document.createElement(tagName);
+    e.src = src;
+    e.onerror = t.unreached_func();
+    e.onloadeddata = t.step_func(function() {
+      assert_equals(e.error, null);
+      t.done();
+    });
+  }, tagName + '.error after successful load');
+
+  // TODO: MEDIA_ERR_ABORTED, MEDIA_ERR_NETWORK, MEDIA_ERR_DECODE
+
+  async_test(function(t) {
+    var e = document.createElement(tagName);
+    e.src = '';
+    e.onerror = t.step_func(function() {
+      assert_true(e.error instanceof MediaError);
+      assert_equals(e.error.code, 4);
+      assert_equals(e.error.code, e.error.MEDIA_ERR_SRC_NOT_SUPPORTED);
+      assert_equals(typeof e.error.message, 'string', 'error.message type');
+      t.done();
+    });
+  }, tagName + '.error after setting src to the empty string');
+}
+
+error_test('audio', getAudioURI('/media/sound_5'));
+error_test('video', getVideoURI('/media/movie_5'));
+</script>

Tests/LibWeb/Text/input/wpt-import/html/semantics/embedded-content/media-elements/location-of-the-media-resource/currentSrc.html

@@ -0,0 +1,48 @@
+<!doctype html>
+<title>currentSrc</title>
+<script src="../../../../../resources/testharness.js"></script>
+<script src="../../../../../resources/testharnessreport.js"></script>
+<div id="log"></div>
+<script>
+['audio', 'video'].forEach(function(tagName) {
+  test(function() {
+    assert_equals(document.createElement(tagName).currentSrc, '');
+  }, tagName + '.currentSrc initial value');
+
+  ['', '.', ' ', 'data:,'].forEach(function(src) {
+    async_test(function(t) {
+      var e = document.createElement(tagName);
+      e.src = src;
+      assert_equals(e.currentSrc, '');
+      e.addEventListener('loadstart', function () {
+        t.step_timeout(function () {
+          if (src == '') {
+            assert_equals(e.currentSrc, '');
+          } else {
+            assert_equals(e.currentSrc, e.src);
+          }
+          t.done();
+        }, 0);
+      })
+    }, tagName + '.currentSrc after setting src attribute "' + src + '"');
+
+    async_test(function(t) {
+      var e = document.createElement(tagName);
+      var s = document.createElement('source');
+      s.src = src;
+      e.appendChild(s);
+      assert_equals(e.currentSrc, '');
+      e.addEventListener('loadstart', function() {
+        t.step_timeout(function () {
+          if (src == '') {
+            assert_equals(e.currentSrc, '');
+          } else {
+            assert_equals(e.currentSrc, s.src);
+          }
+          t.done();
+        }, 0);
+      });
+    }, tagName + '.currentSrc after adding source element with src attribute "' + src + '"');
+  });
+});
+</script>

Tests/LibWeb/Text/input/wpt-import/html/semantics/embedded-content/the-video-element/video_crash_empty_src.html

@@ -0,0 +1,29 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+    <title>HTML5 Media Elements: An empty src should not crash the player.</title>
+    <meta content="text/html; charset=UTF-8" http-equiv="Content-Type">
+    <link rel="author" title="Alicia Boya García" href="mailto:aboya@igalia.com"/>
+    <script src="../../../../resources/testharness.js"></script>
+    <script src="../../../../resources/testharnessreport.js"></script>
+</head>
+<body>
+<script>
+    function makeCrashTest(src) {
+        async_test((test) => {
+            const video = document.createElement("video");
+            video.src = src;
+            video.controls = true;
+            video.addEventListener("error", () => {
+                document.body.removeChild(video);
+                test.done();
+            });
+            document.body.appendChild(video);
+        }, `src="${src}" does not crash.`);
+    }
+
+    makeCrashTest("about:blank");
+    makeCrashTest("");
+</script>
+</body>
+</html>