benchmark: add test_runner/mock-fn

PR-URL: https://github.com/nodejs/node/pull/55771
Refs: https://github.com/nodejs/node/issues/55723
Reviewed-By: Pietro Marchini <pietro.marchini94@gmail.com>
Reviewed-By: Chemi Atlow <chemi@atlow.co.il>
Reviewed-By: Vinícius Lourenço Claro Cardoso <contact@viniciusl.com.br>

benchmark/test_runner/mock-fn.js

@@ -0,0 +1,48 @@
+'use strict';
+
+const common = require('../common');
+const assert = require('node:assert');
+const { test } = require('node:test');
+
+const bench = common.createBenchmark(main, {
+  n: [1e6],
+  mode: ['define', 'execute'],
+}, {
+  // We don't want to test the reporter here
+  flags: ['--test-reporter=./benchmark/fixtures/empty-test-reporter.js'],
+});
+
+const noop = () => {};
+
+function benchmarkDefine(n) {
+  let noDead;
+  test((t) => {
+    bench.start();
+    for (let i = 0; i < n; i++) {
+      noDead = t.mock.fn(noop);
+    }
+    bench.end(n);
+    assert.ok(noDead);
+  });
+}
+
+function benchmarkExecute(n) {
+  let noDead;
+  test((t) => {
+    const mocked = t.mock.fn(noop);
+    bench.start();
+    for (let i = 0; i < n; i++) {
+      noDead = mocked();
+    }
+    bench.end(n);
+    assert.strictEqual(noDead, noop());
+  });
+}
+
+function main({ n, mode }) {
+  if (mode === 'define') {
+    benchmarkDefine(n);
+  } else if (mode === 'execute') {
+    benchmarkExecute(n);
+  }
+}