1 files changed, 49 insertions, 0 deletions
diff --git a/testing/web-platform/tests/js-self-profiling/max-buffer-size.window.js b/testing/web-platform/tests/js-self-profiling/max-buffer-size.window.js
new file mode 100644
index 0000000000..659d4cd14d
--- /dev/null
+++ b/testing/web-platform/tests/js-self-profiling/max-buffer-size.window.js
@@ -0,0 +1,49 @@
+// META: script=resources/profile-utils.js
+
+promise_test(async t => {
+  assert_throws_js(TypeError, () => {
+    new Profiler({ sampleInterval: 10 });
+  });
+}, 'max buffer size must be defined');
+
+promise_test(async t => {
+  const profiler = new Profiler({
+    sampleInterval: 10,
+    maxBufferSize: 2,
+  });
+
+  // Force 3 samples with a max buffer size of 2.
+  for (let i = 0; i < 3; i++) {
+    ProfileUtils.forceSample();
+  }
+
+  const trace = await profiler.stop();
+  assert_equals(trace.samples.length, 2);
+}, 'max buffer size is not exceeded');
+
+promise_test(async t => {
+  const largeBufferProfiler = new Profiler({ sampleInterval: 10,  maxBufferSize: Number.MAX_SAFE_INTEGER });
+  const smallBufferProfiler = new Profiler({ sampleInterval: 10,  maxBufferSize: 1 });
+
+  const watcher = new EventWatcher(t, smallBufferProfiler, ['samplebufferfull']);
+
+  largeBufferProfiler.addEventListener('samplebufferfull', () => {
+    assert_unreached('samplebufferfull invoked on wrong profiler');
+    largeBufferProfiler.stop();
+    smallBufferProfiler.stop();
+  });
+
+  smallBufferProfiler.addEventListener('samplebufferfull', () => {
+    largeBufferProfiler.stop();
+    smallBufferProfiler.stop();
+  });
+
+  // Force two samples to be taken, which should exceed
+  // |smallBufferProfiler|'s buffer size.
+  for (let i = 0; i < 2; i++) {
+    ProfileUtils.forceSample();
+  }
+
+  // Ensure that |smallBufferProfiler|'s buffer size is exceeded.
+  await watcher.wait_for('samplebufferfull');
+}, 'ensure samplebufferfull is fired on full profiler');