feat: add performance user timing APIs (#6421)

cli/tests/unit/performance_test.ts

@@ -1,5 +1,10 @@
 // Copyright 2018-2020 the Deno authors. All rights reserved. MIT license.
-import { unitTest, assert, createResolvable } from "./test_util.ts";
+import {
+  unitTest,
+  assert,
+  assertEquals,
+  createResolvable,
+} from "./test_util.ts";
 
 unitTest({ perms: { hrtime: false } }, async function performanceNow(): Promise<
   void
@@ -13,3 +18,42 @@ unitTest({ perms: { hrtime: false } }, async function performanceNow(): Promise<
   }, 10);
   await resolvable;
 });
+
+unitTest(function performanceMark() {
+  const mark = performance.mark("test");
+  assert(mark instanceof PerformanceMark);
+  assertEquals(mark.detail, null);
+  assertEquals(mark.name, "test");
+  assertEquals(mark.entryType, "mark");
+  assert(mark.startTime > 0);
+  assertEquals(mark.duration, 0);
+  const entries = performance.getEntries();
+  assert(entries[entries.length - 1] === mark);
+  const markEntries = performance.getEntriesByName("test", "mark");
+  assert(markEntries[markEntries.length - 1] === mark);
+});
+
+unitTest(function performanceMeasure() {
+  const mark = performance.mark("test");
+  return new Promise((resolve, reject) => {
+    setTimeout(() => {
+      try {
+        const measure = performance.measure("test", "test");
+        assert(measure instanceof PerformanceMeasure);
+        assertEquals(measure.detail, null);
+        assertEquals(measure.name, "test");
+        assertEquals(measure.entryType, "measure");
+        assert(measure.startTime > 0);
+        assertEquals(mark.startTime, measure.startTime);
+        assert(measure.duration >= 100 && measure.duration < 200);
+        const entries = performance.getEntries();
+        assert(entries[entries.length - 1] === measure);
+        const measureEntries = performance.getEntriesByName("test", "measure");
+        assert(measureEntries[measureEntries.length - 1] === measure);
+      } catch (e) {
+        return reject(e);
+      }
+      resolve();
+    }, 100);
+  });
+});