1 files changed, 214 insertions, 0 deletions
diff --git a/testing/web-platform/tests/html/semantics/scripting-1/the-script-element/moving-between-documents/resources/moving-between-documents-helper.js b/testing/web-platform/tests/html/semantics/scripting-1/the-script-element/moving-between-documents/resources/moving-between-documents-helper.js
new file mode 100644
index 0000000000..de4af6ac10
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+++ b/testing/web-platform/tests/html/semantics/scripting-1/the-script-element/moving-between-documents/resources/moving-between-documents-helper.js
@@ -0,0 +1,214 @@
+"use strict";
+
+function createDocument(documentType, result, inlineOrExternal, type, hasBlockingStylesheet) {
+  return new Promise((resolve, reject) => {
+    const iframe = document.createElement("iframe");
+    iframe.src =
+      "resources/moving-between-documents-iframe.py" +
+      "?result=" + result +
+      "&inlineOrExternal=" + inlineOrExternal +
+      "&type=" + type +
+      "&hasBlockingStylesheet=" + hasBlockingStylesheet +
+      "&cache=" + Math.random();
+    // As blocking stylesheets delays Document load events, we use
+    // DOMContentLoaded here.
+    // After that point, we expect iframe.contentDocument exists
+    // while still waiting for blocking stylesheet loading.
+    document.body.appendChild(iframe);
+
+    window.addEventListener('message', (event) => {
+      if (documentType === "iframe") {
+        resolve([iframe.contentWindow, iframe.contentDocument]);
+      } else if (documentType === "createHTMLDocument") {
+        resolve([
+            iframe.contentWindow,
+            iframe.contentDocument.implementation.createHTMLDocument("")]);
+      } else {
+        reject(new Error("Invalid document type: " + documentType));
+      }
+    }, {once: true});
+  });
+}
+
+window.didExecute = undefined;
+
+// For a script, there are three associated Documents that can
+// potentially different:
+//
+// [1] script's parser document
+//     https://html.spec.whatwg.org/C/#parser-document
+//
+// [2] script's preparation-time document
+//     https://html.spec.whatwg.org/C/#preparation-time-document
+//     == script's node document at the beginning of #prepare-a-script
+//
+// [3] script's node document at the beginning of
+//     #execute-the-script-block
+//
+// This helper is for tests where [1]/[2]/[3] are different.
+
+// In the spec, scripts are executed only if [1]/[2]/[3] are all the same
+// (or [1] is null and [2]==[3]).
+//
+// A check for [1]==[2] is in #prepare-a-script and
+// a check for [1]==[3] is in #execute-the-script-block,
+// but these are under debate: https://github.com/whatwg/html/issues/2137
+//
+// A check for [2]==[3] is in #execute-the-script-block, which is added by
+// https://github.com/whatwg/html/pull/2673
+
+// timing:
+//   "before-prepare":
+//     A <script> is moved during parsing before #prepare-a-script.
+//     [1] != [2] == [3]
+//
+//   "after-prepare":
+//     A <script> is moved after parsing/#prepare-a-script but
+//     before #execute-the-script-block.
+//     [1] == [2] != [3]
+//
+//     To move such scripts, #has-a-style-sheet-that-is-blocking-scripts
+//     is utilized to block inline scripts after #prepare-a-script.
+//     Note: this is a corner case in the spec which might be removed
+//     from the spec in the future, e.g.
+//     https://github.com/whatwg/html/issues/1349
+//     https://github.com/chrishtr/rendering/blob/master/stylesheet-loading-proposal.md
+//
+//   TODO(domfarolino): Remove the "parsing but moved back" tests, because if a
+//   <script> is moved before #prepare-a-script, per spec it should never make
+//   it to #execute-the-script-block. If an implementation does not implement
+//   the check in #prepare-a-script, then it will fail the "before-prepare"
+//   tests, so these are not necessary.
+//   "parsing but moved back"
+//     A <script> is moved before #prepare-a-script, but moved back again
+//     to the original Document after #prepare-a-script.
+//     [1] == [3] != [2]
+//
+// destType: "iframe" or "createHTMLDocument".
+// result: "fetch-error", "parse-error", or "success".
+// inlineOrExternal: "inline" or "external" or "empty-src".
+// type: "classic" or "module".
+async function runTest(timing, destType, result, inlineOrExternal, type) {
+  const description =
+      `Move ${result} ${inlineOrExternal} ${type} script ` +
+      `to ${destType} ${timing}`;
+
+  const t = async_test("Eval: " + description);
+  const tScriptLoadEvent = async_test("<script> load: " + description);
+  const tScriptErrorEvent = async_test("<script> error: " + description);
+  const tWindowErrorEvent = async_test("window error: " + description);
+
+  // If scripts should be moved after #prepare-a-script before
+  // #execute-the-script-block, we add a style sheet that is
+  // blocking scripts.
+  const hasBlockingStylesheet =
+      timing === "after-prepare" || timing === "move-back";
+
+  const [sourceWindow, sourceDocument] = await createDocument(
+      "iframe", result, inlineOrExternal, type, hasBlockingStylesheet);
+
+  // Due to https://crbug.com/1034176, Chromium needs
+  // blocking stylesheets also in the destination Documents.
+  const [destWindow, destDocument] = await createDocument(
+      destType, null, null, null, hasBlockingStylesheet);
+
+  const scriptOnLoad =
+    tScriptLoadEvent.unreached_func("Script load event fired unexpectedly");
+  const scriptOnError = (event) => {
+    // For Firefox: Prevent window.onerror is fired due to propagation
+    // from <script>'s error event.
+    event.stopPropagation();
+
+    tScriptErrorEvent.unreached_func("Script error evennt fired unexpectedly")();
+  };
+
+  sourceWindow.didExecute = false;
+  sourceWindow.t = t;
+  sourceWindow.scriptOnLoad = scriptOnLoad;
+  sourceWindow.scriptOnError = scriptOnError;
+  sourceWindow.onerror = tWindowErrorEvent.unreached_func(
+      "Window error event shouldn't fired on source window");
+  sourceWindow.readyToEvaluate = false;
+
+  destWindow.didExecute = false;
+  destWindow.t = t;
+  destWindow.scriptOnLoad = scriptOnLoad;
+  destWindow.scriptOnError = scriptOnError;
+  destWindow.onerror = tWindowErrorEvent.unreached_func(
+      "Window error event shouldn't fired on destination window");
+  destWindow.readyToEvaluate = false;
+
+  // t=0 sec: Move between documents before #prepare-a-script.
+  // At this time, the script element is not yet inserted to the DOM.
+  if (timing === "before-prepare" || timing === "move-back") {
+    destDocument.body.appendChild(
+      sourceDocument.querySelector("streaming-element"));
+  }
+  if (timing === "before-prepare") {
+    sourceWindow.readyToEvaluate = true;
+    destWindow.readyToEvaluate = true;
+  }
+
+  // t=1 sec: the script element is inserted to the DOM, i.e.
+  // #prepare-a-script is triggered (see monving-between-documents-iframe.py).
+  // In the case of `before-prepare`, the script can be evaluated.
+  // In other cases, the script evaluation is blocked by a style sheet.
+  await new Promise(resolve => step_timeout(resolve, 2000));
+
+  // t=2 sec: Move between documents after #prepare-a-script.
+  if (timing === "after-prepare") {
+    // At this point, the script hasn't been moved yet, so we'll move it for the
+    // first time, after #prepare-a-script, but before #execute-the-script-block.
+    destDocument.body.appendChild(
+      sourceDocument.querySelector("streaming-element"));
+  } else if (timing === "move-back") {
+    // At this point the script has already been moved to the destination block
+    // before #prepare-a-script, so we'll move it back to the source document
+    // before #execute-the-script-block.
+    sourceDocument.body.appendChild(
+      destDocument.querySelector("streaming-element"));
+  }
+  sourceWindow.readyToEvaluate = true;
+  destWindow.readyToEvaluate = true;
+
+  // t=3 or 5 sec: Blocking stylesheet and external script are loaded,
+  // and thus script evaulation is unblocked.
+
+  // Note: scripts are expected to be loaded at t=3, because the fetch
+  // is started by #prepare-a-script at t=1, and the script's delay is
+  // 2 seconds. However in Chromium, due to preload scanner, the script
+  // loading might take 4 seconds, because the first request by preload
+  // scanner of the source Document takes 2 seconds (between t=1 and t=3)
+  // which blocks the second request by #prepare-a-script that takes
+  // another 2 seconds (between t=3 and t=5).
+
+  // t=6 sec: After all possible script evaluation points, test whether
+  // the script/events were evaluated/fired or not.
+  // As we have concurrent tests, a single global step_timeout() is
+  // used instead of multiple `t.step_timeout()` etc.,
+  // to avoid potential race conditions between `t.step_timeout()`s.
+  return new Promise(resolve => {
+    step_timeout(() => {
+      tWindowErrorEvent.done();
+      tScriptLoadEvent.done();
+      tScriptErrorEvent.done();
+
+      t.step_func_done(() => {
+        assert_false(sourceWindow.didExecute,
+          "The script must not have executed in source window");
+        assert_false(destWindow.didExecute,
+          "The script must not have executed in destination window");
+      })();
+      resolve();
+    }, 4000);
+  });
+}
+
+async_test(t => {
+  t.step_timeout(() => {
+      assert_equals(window.didExecute, undefined,
+        "The script must not have executed in the top-level window");
+      t.done();
+    },
+    4000);
+}, "Sanity check around top-level Window");