1 files changed, 51 insertions, 0 deletions
diff --git a/testing/web-platform/tests/fs/resources/messaging-blob-helpers.js b/testing/web-platform/tests/fs/resources/messaging-blob-helpers.js
new file mode 100644
index 0000000000..852f2e2d32
--- /dev/null
+++ b/testing/web-platform/tests/fs/resources/messaging-blob-helpers.js
@@ -0,0 +1,51 @@
+'use strict';
+
+// Creates a blob URL with the contents of 'message-target.html'. Use the
+// blob as an iframe src or a window.open() URL, which creates a same origin
+// message target.
+async function create_message_target_blob_url(test) {
+  const html = await create_message_target_html_without_subresources(test);
+  const blob = new Blob([html], { type: 'text/html' });
+  return URL.createObjectURL(blob);
+}
+
+// Creates a data URI with the contents of 'message-target.html'. Use the
+// data URI as an iframe src, which creates a cross origin message target.
+async function create_message_target_data_uri(test) {
+  const iframe_html =
+    await create_message_target_html_without_subresources(test);
+  return `data:text/html,${encodeURIComponent(iframe_html)}`;
+}
+
+// Constructs a version of 'message-target.html' without any subresources.
+// Enables the creation of blob URLs, data URIs and iframe srcdocs re-using
+// the contents of 'message-target.html'.
+async function create_message_target_html_without_subresources(test) {
+  const test_helpers_script = await fetch_text('resources/test-helpers.js');
+
+  const messaging_helpers_script =
+    await fetch_text('resources/messaging-helpers.js');
+
+  const messaging_serialize_helpers_script =
+    await fetch_text('resources/messaging-serialize-helpers.js');
+
+  const message_target_script =
+    await fetch_text('resources/message-target.js');
+
+  // Get the inline script code from 'message-target.html'.
+  const iframe = await add_iframe(test, { src: 'resources/message-target.html' });
+  const iframe_script =
+    iframe.contentWindow.document.getElementById('inline_script').outerHTML;
+  iframe.remove();
+
+  return '<!DOCTYPE html>' +
+    `<script>${test_helpers_script}</script>` +
+    `<script>${messaging_serialize_helpers_script}</script>` +
+    `<script>${message_target_script}</script>` +
+    `${iframe_script}`;
+}
+
+async function fetch_text(url) {
+  const response = await fetch(url);
+  return await response.text();
+}