1 files changed, 44 insertions, 0 deletions
diff --git a/testing/web-platform/tests/user-timing/user-timing-tojson.html b/testing/web-platform/tests/user-timing/user-timing-tojson.html
new file mode 100644
index 0000000000..6aef7fa904
--- /dev/null
+++ b/testing/web-platform/tests/user-timing/user-timing-tojson.html
@@ -0,0 +1,44 @@
+<!doctype html>
+<html>
+<head>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+</head>
+<body>
+<script>
+const keys = [
+  'name',
+  'entryType',
+  'startTime',
+  'duration',
+];
+test(() => {
+  performance.mark('a');
+  const markEntries = performance.getEntriesByType('mark');
+  assert_equals(1, markEntries.length);
+  const markEntry = markEntries[0];
+  assert_equals(markEntry.entryType, 'mark');
+  assert_equals(typeof(markEntry.toJSON), 'function');
+  const markJSON = markEntry.toJSON();
+  assert_equals(typeof(markJSON), 'object');
+  for (const key of keys) {
+    assert_equals(markJSON[key], markEntry[key], `PerformanceMark ${key} entry does not match its toJSON value`);
+  }
+}, 'Test toJSON() in PerformanceMark');
+
+test(() => {
+  performance.measure('m');
+  const measureEntries = performance.getEntriesByType('measure');
+  assert_equals(1, measureEntries.length);
+  const measureEntry = measureEntries[0];
+  assert_equals(measureEntry.entryType, 'measure');
+  assert_equals(typeof(measureEntry.toJSON), 'function');
+  const measureJSON = measureEntry.toJSON();
+  assert_equals(typeof(measureJSON), 'object');
+  for (const key of keys) {
+    assert_equals(measureJSON[key], measureEntry[key], `PerformanceMeasure ${key} entry does not match its toJSON value`);
+  }
+}, 'Test toJSON() in PerformanceMeasure');
+</script>
+</body>
+</html>