Update web-platform-tests to revision c0a3e93389bdcc9e8ad12d3988e4568d48b78c9d

tests/wpt/web-platform-tests/resources/sriharness.js

@@ -1,3 +1,5 @@
+// TODO(domfarolino): Refactor SRIScriptTest to just be a function instead of a
+// constructor, since there is no need to produce another object.
 var SRIScriptTest = function(pass, name, src, integrityValue, crossoriginValue, nonce) {
     this.pass = pass;
     this.name = "Script: " + name;
@@ -32,6 +34,100 @@ SRIScriptTest.prototype.execute = function() {
     document.body.appendChild(e);
 };
 
+function buildElementFromDestination(resource_url, destination, attrs) {
+  // Assert: |destination| is a valid destination.
+  let element;
+
+  // The below switch is responsible for:
+  //   1. Creating the correct subresource element
+  //   2. Setting said element's href, src, or fetch-instigating property
+  //      appropriately.
+  switch (destination) {
+    case "script":
+      element = document.createElement(destination);
+      element.src = resource_url;
+      break;
+    case "style":
+      element = document.createElement('link');
+      element.rel = 'stylesheet';
+      element.href = resource_url;
+      break;
+    case "image":
+      element = document.createElement('img');
+      element.src = resource_url;
+      break;
+    default:
+      assert_unreached("INVALID DESTINATION");
+  }
+
+  // Apply the rest of the attributes, if any.
+  for (const [attr_name, attr_val] of Object.entries(attrs)) {
+    element[attr_name] = attr_val;
+  }
+
+  return element;
+}
+
+const SRIPreloadTest = (preload_sri_success, subresource_sri_success, name,
+                        destination, resource_url, link_attrs,
+                        subresource_attrs) => {
+  const test = async_test(name);
+  const link = document.createElement('link');
+
+  // Early-fail in UAs that do not support `preload` links.
+  test.step_func(() => {
+    assert_true(link.relList.supports('preload'),
+      "This test is automatically failing because the browser does not" +
+      "support `preload` links.");
+  })();
+
+  // Build up the link.
+  link.rel = 'preload';
+  link.as = destination;
+  link.href = resource_url;
+  for (const [attr_name, attr_val] of Object.entries(link_attrs)) {
+    link[attr_name] = attr_val; // This may override `rel` to modulepreload.
+  }
+
+  // Preload + subresource success and failure loading functions.
+  const valid_preload_failed = test.step_func(() =>
+    { assert_unreached("Valid preload fired error handler.") });
+  const invalid_preload_succeeded = test.step_func(() =>
+    { assert_unreached("Invalid preload load succeeded.") });
+  const valid_subresource_failed = test.step_func(() =>
+    { assert_unreached("Valid subresource fired error handler.") });
+  const invalid_subresource_succeeded = test.step_func(() =>
+    { assert_unreached("Invalid subresource load succeeded.") });
+  const subresource_pass = test.step_func(() => { test.done(); });
+  const preload_pass = test.step_func(() => {
+    const subresource_element = buildElementFromDestination(
+      resource_url,
+      destination,
+      subresource_attrs
+    );
+
+    if (subresource_sri_success) {
+      subresource_element.onload = subresource_pass;
+      subresource_element.onerror = valid_subresource_failed;
+    } else {
+      subresource_element.onload = invalid_subresource_succeeded;
+      subresource_element.onerror = subresource_pass;
+    }
+
+    document.body.append(subresource_element);
+  });
+
+  if (preload_sri_success) {
+    link.onload = preload_pass;
+    link.onerror = valid_preload_failed;
+  } else {
+    link.onload = invalid_preload_succeeded;
+    link.onerror = preload_pass;
+  }
+
+  document.head.append(link);
+}
+
 // <link> tests
 // Style tests must be done synchronously because they rely on the presence
 // and absence of global style, which can affect later tests. Thus, instead
@@ -63,6 +159,8 @@ SRIStyleTest.prototype.execute = function() {
     var div = document.createElement("div");
     div.className = "testdiv";
     var e = document.createElement("link");
+
+    // The link relation is guaranteed to not be "preload" or "modulepreload".
     this.attrs.rel = this.attrs.rel || "stylesheet";
     for (var key in this.attrs) {
         if (this.attrs.hasOwnProperty(key)) {