test_runner: add multiple files benchmark

benchmark/test_runner/multi-files.js

@@ -0,0 +1,27 @@
+'use strict';
+const common = require('../common');
+
+const bench = common.createBenchmark(main, {
+  patterns: ['test/fixtures/test-runner/**/*.?(c|m)js', 'test/parallel/test-runner-*'],
+  concurrency: ['yes', 'no'],
+}, {
+  flags: ['--expose-internals'],
+});
+
+
+function main({ patterns, concurrency }) {
+  const { run } = require('node:test');
+  const { Glob } = require('internal/fs/glob');
+  const glob = new Glob([patterns]);
+  const files = glob.globSync().filter((f) => !f.includes('never_ending') && !f.includes('watch-mode'));
+  concurrency = concurrency === 'yes';
+  let tests = 0;
+
+  bench.start();
+  (async function() {
+    const stream = run({ concurrency, files });
+    for await (const { type } of stream) {
+      if (type === 'test:start') tests++;
+    }
+  })().then(() => bench.end(tests));
+}