1 files changed, 61 insertions, 0 deletions
diff --git a/devtools/client/performance-new/test/browser/browser_devtools-previously-started.js b/devtools/client/performance-new/test/browser/browser_devtools-previously-started.js
new file mode 100644
index 0000000000..41612c94e4
--- /dev/null
+++ b/devtools/client/performance-new/test/browser/browser_devtools-previously-started.js
@@ -0,0 +1,61 @@
+/* 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/. */
+
+"use strict";
+
+add_task(async function test() {
+  info(
+    "Test what happens if the profiler was previously started by another tool."
+  );
+
+  const { startProfiler } = ChromeUtils.import(
+    "resource://devtools/client/performance-new/shared/background.jsm.js"
+  );
+
+  info("Start the profiler before DevTools is loaded.");
+  startProfiler("aboutprofiling");
+
+  await withDevToolsPanel(async document => {
+    const getRecordingState = setupGetRecordingState(document);
+
+    // The initial state of the profiler UI is racy, as it calls out to the PerfFront
+    // to get the status of the profiler. This can race with the initialization of
+    // the test. Most of the the time the result is "not-yet-known", but rarely
+    // the PerfFront will win this race. Allow for both outcomes of the race in this
+    // test.
+    ok(
+      getRecordingState() === "not-yet-known" ||
+        getRecordingState() === "recording",
+      "The component starts out in an unknown state or in a recording state."
+    );
+
+    const cancelRecording = await getActiveButtonFromText(
+      document,
+      "Cancel recording"
+    );
+
+    is(
+      getRecordingState(),
+      "recording",
+      "The profiler is reflecting the recording state."
+    );
+
+    info("Click the button to cancel the recording");
+    cancelRecording.click();
+
+    is(
+      getRecordingState(),
+      "request-to-stop-profiler",
+      "We can request to stop the profiler."
+    );
+
+    await getActiveButtonFromText(document, "Start recording");
+
+    is(
+      getRecordingState(),
+      "available-to-record",
+      "The profiler is now available to record."
+    );
+  });
+});