1 files changed, 58 insertions, 0 deletions
diff --git a/cli/js/tests/metrics_test.ts b/cli/js/tests/metrics_test.ts
new file mode 100644
index 000000000..9b7d83887
--- /dev/null
+++ b/cli/js/tests/metrics_test.ts
@@ -0,0 +1,58 @@
+// Copyright 2018-2020 the Deno authors. All rights reserved. MIT license.
+import { unitTest, assert } from "./test_util.ts";
+
+unitTest(async function metrics(): Promise<void> {
+  const m1 = Deno.metrics();
+  assert(m1.opsDispatched > 0);
+  assert(m1.opsDispatchedSync > 0);
+  assert(m1.opsCompleted > 0);
+  assert(m1.opsCompletedSync > 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([13, 13, 13]); // "\r\r\r",
+  await Deno.stdout.write(dataMsg);
+
+  const m2 = Deno.metrics();
+  assert(m2.opsDispatched > m1.opsDispatched);
+  assert(m2.opsDispatchedSync > m1.opsDispatchedSync);
+  assert(m2.opsDispatchedAsync > m1.opsDispatchedAsync);
+  assert(m2.opsCompleted > m1.opsCompleted);
+  assert(m2.opsCompletedSync > m1.opsCompletedSync);
+  assert(m2.opsCompletedAsync > m1.opsCompletedAsync);
+  assert(m2.bytesSentControl > m1.bytesSentControl);
+  assert(m2.bytesSentData >= m1.bytesSentData + dataMsg.byteLength);
+  assert(m2.bytesReceived > m1.bytesReceived);
+});
+
+unitTest(
+  { perms: { write: true } },
+  function metricsUpdatedIfNoResponseSync(): void {
+    const filename = Deno.makeTempDirSync() + "/test.txt";
+
+    const data = new Uint8Array([41, 42, 43]);
+    Deno.writeFileSync(filename, data, { mode: 0o666 });
+
+    const metrics = Deno.metrics();
+    assert(metrics.opsDispatched === metrics.opsCompleted);
+    assert(metrics.opsDispatchedSync === metrics.opsCompletedSync);
+  }
+);
+
+unitTest(
+  { perms: { 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, { mode: 0o666 });
+
+    const metrics = Deno.metrics();
+    assert(metrics.opsDispatched === metrics.opsCompleted);
+    assert(metrics.opsDispatchedSync === metrics.opsCompletedSync);
+    assert(metrics.opsDispatchedAsync === metrics.opsCompletedAsync);
+  }
+);