1 files changed, 126 insertions, 0 deletions
diff --git a/devtools/client/performance-new/test/browser/fake-frontend.html b/devtools/client/performance-new/test/browser/fake-frontend.html
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+++ b/devtools/client/performance-new/test/browser/fake-frontend.html
@@ -0,0 +1,126 @@
+<!DOCTYPE html>
+<!-- This Source Code Form is subject to the terms of the Mozilla Public
+   - License, v. 2.0. If a copy of the MPL was not distributed with this
+   - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
+<html>
+  <head>
+    <meta charset="utf-8"/>
+    <title></title>
+  </head>
+  <body>
+    <script>
+      "use strict";
+      // This file is used to test the injection of performance profiles into a front-end,
+      // specifically the mechanism used to inject into profiler.firefox.com. Rather
+      // than using some kind of complicated message passing scheme to talk to the test
+      // harness, modify the title of the page. The tests can easily read the window
+      // title to see if things worked as expected.
+
+      // The following are the titles used to communicate the page's state to the tests.
+      // Keep these in sync with any tests that read them.
+      const initialTitle = "Waiting on the profile";
+      const successTitle = "Profile received";
+      const errorTitle = "Error"
+
+      document.title = initialTitle;
+
+      // A function which requests the profile from the browser using the GET_PROFILE
+      // WebChannel message.
+      function getProfile() {
+        return new Promise((resolve, reject) => {
+          const requestId = 0;
+
+          function listener(event) {
+            window.removeEventListener(
+              "WebChannelMessageToContent",
+              listener,
+              true
+            );
+
+            const { id, message } = event.detail;
+
+            if (id !== "profiler.firefox.com" ||
+              !message ||
+              typeof message !== "object"
+            ) {
+              console.error(message);
+              reject(new Error("A malformed WebChannel event was received."));
+              return;
+            }
+
+            if (!message.type) {
+              console.error(message);
+              reject(new Error("The WebChannel event indicates an error."));
+              return;
+            }
+
+            if (message.requestId === requestId) {
+              if (message.type === "SUCCESS_RESPONSE") {
+                resolve(message.response);
+              } else {
+                reject(new Error(message.error));
+              }
+            }
+          }
+
+          window.addEventListener("WebChannelMessageToContent", listener, true);
+
+          window.dispatchEvent(
+            new CustomEvent("WebChannelMessageToChrome", {
+              detail: JSON.stringify({
+                id: "profiler.firefox.com",
+                message: { type: "GET_PROFILE", requestId },
+              }),
+            })
+          );
+        })
+      }
+
+      async function runTest() {
+        try {
+          // Get the profile.
+          const profile = await getProfile();
+
+          // Check that the profile is somewhat reasonable. It should be a gzipped
+          // profile, so we can only lightly check some properties about it, and check
+          // that it is an ArrayBuffer.
+          //
+          // After the check, modify the title of the document, so the tab title gets
+          // updated. This is an easy way to pass a message to the test script.
+          if (
+            profile &&
+            typeof profile === 'object' &&
+            (
+              // The popup injects the compressed profile as an ArrayBuffer.
+              (profile instanceof ArrayBuffer) ||
+              // DevTools injects the profile as just the plain object, although
+              // maybe in the future it could also do it as a compressed profile
+              // to make this faster (bug 1581963).
+              Object.keys(profile).includes("threads")
+            )
+          ) {
+            // The profile looks good!
+            document.title = successTitle;
+          } else {
+            // The profile doesn't look right, surface the error to the terminal.
+            dump('The gecko profile was malformed in fake-frontend.html\n');
+            dump(`Profile: ${JSON.stringify(profile)}\n`);
+
+            // Also to the web console.
+            console.error(profile);
+
+            // Report the error to the tab title.
+            document.title = errorTitle;
+          }
+        } catch (error) {
+          // Catch any error and notify the test.
+          document.title = errorTitle;
+          dump('An error was caught in fake-frontend.html\n');
+          dump(`${error}\n`);
+        }
+      }
+
+      runTest();
+    </script>
+  </body>
+</html>