1 files changed, 46 insertions, 0 deletions
diff --git a/cli/js/metrics_test.ts b/cli/js/metrics_test.ts
new file mode 100644
index 000000000..de41a0cb1
--- /dev/null
+++ b/cli/js/metrics_test.ts
@@ -0,0 +1,46 @@
+// Copyright 2018-2019 the Deno authors. All rights reserved. MIT license.
+import { test, testPerm, assert } from "./test_util.ts";
+
+test(async function metrics(): Promise<void> {
+  const m1 = Deno.metrics();
+  assert(m1.opsDispatched > 0);
+  assert(m1.opsCompleted > 0);
+  assert(m1.bytesSentControl > 0);
+  assert(m1.bytesSentData >= 0);
+  assert(m1.bytesReceived > 0);
+
+  // Write to stdout to ensure a "data" message gets sent instead of just
+  // control messages.
+  const dataMsg = new Uint8Array([41, 42, 43]);
+  await Deno.stdout.write(dataMsg);
+
+  const m2 = Deno.metrics();
+  assert(m2.opsDispatched > m1.opsDispatched);
+  assert(m2.opsCompleted > m1.opsCompleted);
+  assert(m2.bytesSentControl > m1.bytesSentControl);
+  assert(m2.bytesSentData >= m1.bytesSentData + dataMsg.byteLength);
+  assert(m2.bytesReceived > m1.bytesReceived);
+});
+
+testPerm({ write: true }, function metricsUpdatedIfNoResponseSync(): void {
+  const filename = Deno.makeTempDirSync() + "/test.txt";
+
+  const data = new Uint8Array([41, 42, 43]);
+  Deno.writeFileSync(filename, data, { perm: 0o666 });
+
+  const metrics = Deno.metrics();
+  assert(metrics.opsDispatched === metrics.opsCompleted);
+});
+
+testPerm(
+  { write: true },
+  async function metricsUpdatedIfNoResponseAsync(): Promise<void> {
+    const filename = Deno.makeTempDirSync() + "/test.txt";
+
+    const data = new Uint8Array([41, 42, 43]);
+    await Deno.writeFile(filename, data, { perm: 0o666 });
+
+    const metrics = Deno.metrics();
+    assert(metrics.opsDispatched === metrics.opsCompleted);
+  }
+);