1 files changed, 83 insertions, 0 deletions
diff --git a/testing/web-platform/tests/web-locks/resources/helpers.js b/testing/web-platform/tests/web-locks/resources/helpers.js
new file mode 100644
index 0000000000..4b3311eee6
--- /dev/null
+++ b/testing/web-platform/tests/web-locks/resources/helpers.js
@@ -0,0 +1,83 @@
+// Test helpers used by multiple Web Locks API tests.
+(() => {
+
+  // Generate a unique resource identifier, using the script path and
+  // test case name. This is useful to avoid lock interference between
+  // test cases.
+  let res_num = 0;
+  self.uniqueName = (testCase, prefix) => {
+    return `${self.location.pathname}-${prefix}-${testCase.name}-${++res_num}`;
+  };
+  self.uniqueNameByQuery = () => {
+    const prefix = new URL(location.href).searchParams.get('prefix');
+    return `${prefix}-${++res_num}`;
+  }
+
+  // Inject an iframe showing the given url into the page, and resolve
+  // the returned promise when the frame is loaded.
+  self.iframe = url => new Promise(resolve => {
+    const element = document.createElement('iframe');
+    element.addEventListener(
+      'load', () => { resolve(element); }, { once: true });
+    element.src = url;
+    document.documentElement.appendChild(element);
+  });
+
+  // Post a message to the target frame, and resolve the returned
+  // promise when a response comes back. The posted data is annotated
+  // with unique id to track the response. This assumes the use of
+  // 'iframe.html' as the frame, which implements this protocol.
+  let next_request_id = 0;
+  self.postToFrameAndWait = (frame, data) => {
+    const iframe_window = frame.contentWindow;
+    data.rqid = next_request_id++;
+    iframe_window.postMessage(data, '*');
+    return new Promise(resolve => {
+      const listener = event => {
+        if (event.source !== iframe_window || event.data.rqid !== data.rqid)
+          return;
+        self.removeEventListener('message', listener);
+        resolve(event.data);
+      };
+      self.addEventListener('message', listener);
+    });
+  };
+
+  // Post a message to the target worker, and resolve the returned
+  // promise when a response comes back. The posted data is annotated
+  // with unique id to track the response. This assumes the use of
+  // 'worker.js' as the worker, which implements this protocol.
+  self.postToWorkerAndWait = (worker, data) => {
+    return new Promise(resolve => {
+      data.rqid = next_request_id++;
+      worker.postMessage(data);
+      const listener = event => {
+        if (event.data.rqid !== data.rqid)
+          return;
+        worker.removeEventListener('message', listener);
+        resolve(event.data);
+      };
+      worker.addEventListener('message', listener);
+    });
+  };
+
+  /**
+   * Request a lock and hold it until the subtest ends.
+   * @param {*} t test runner object
+   * @param {string} name lock name
+   * @param {LockOptions=} options lock options
+   * @returns
+   */
+  self.requestLockAndHold = (t, name, options = {}) => {
+    return navigator.locks.request(name, options, () => {
+      return new Promise(resolve => t.add_cleanup(resolve));
+    });
+  };
+
+  self.makePromiseAndResolveFunc = () => {
+    let resolve;
+    const promise = new Promise(r => { resolve = r; });
+    return [promise, resolve];
+  };
+
+})();