1 files changed, 63 insertions, 0 deletions
diff --git a/tools/profiler/tests/xpcshell/test_feature_js.js b/tools/profiler/tests/xpcshell/test_feature_js.js
new file mode 100644
index 0000000000..a5949e4a0c
--- /dev/null
+++ b/tools/profiler/tests/xpcshell/test_feature_js.js
@@ -0,0 +1,63 @@
+/* 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/. */
+
+/**
+ * Test that JS capturing works as expected.
+ */
+add_task(async () => {
+  const entries = 10000;
+  const interval = 1;
+  const threads = [];
+  const features = ["js"];
+
+  await Services.profiler.StartProfiler(entries, interval, features, threads);
+
+  // Call the following to get a nice stack in the profiler:
+  // functionA -> functionB -> functionC -> captureAtLeastOneJsSample
+  const sampleIndex = await functionA();
+
+  const profile = await stopNowAndGetProfile();
+
+  const [thread] = profile.threads;
+  const { samples } = thread;
+
+  const inflatedStackFrames = getInflatedStackLocations(
+    thread,
+    samples.data[sampleIndex]
+  );
+
+  expectStackToContain(
+    inflatedStackFrames,
+    [
+      "(root)",
+      "js::RunScript",
+      // The following regexes match a string similar to:
+      //
+      // "functionA (/gecko/obj/_tests/xpcshell/tools/profiler/tests/xpcshell/test_feature_js.js:47:0)"
+      // or
+      // "functionA (test_feature_js.js:47:0)"
+      //
+      //          this matches the script location
+      //          |                       match the line number
+      //          |                       |   match the column number
+      //          v                       v   v
+      /^functionA \(.*test_feature_js\.js:\d+:\d+\)$/,
+      /^functionB \(.*test_feature_js\.js:\d+:\d+\)$/,
+      /^functionC \(.*test_feature_js\.js:\d+:\d+\)$/,
+    ],
+    "The stack contains a few frame labels, as well as the JS functions that we called."
+  );
+});
+
+function functionA() {
+  return functionB();
+}
+
+function functionB() {
+  return functionC();
+}
+
+async function functionC() {
+  return captureAtLeastOneJsSample();
+}