test_runner: support directory arguments to --test

lib/internal/test_runner/runner.js

@@ -34,9 +34,10 @@ const {
 } = primordials;
 
 const { spawn } = require('child_process');
+const { statSync } = require('fs');
 const { finished } = require('internal/streams/end-of-stream');
 const { availableParallelism } = require('os');
-const { resolve, sep, isAbsolute } = require('path');
+const { resolve, sep, isAbsolute, join } = require('path');
 const { DefaultDeserializer, DefaultSerializer } = require('v8');
 const { getOptionValue, getOptionsAsFlagsFromBinding } = require('internal/options');
 const { Interface } = require('internal/readline/interface');
@@ -154,11 +155,41 @@ function createTestFileList(patterns, cwd) {
   if (!patterns || patterns.length === 0) {
     patterns = [kDefaultPattern];
   }
-  const glob = new Glob(patterns, {
+  const globOptions = {
     __proto__: null,
     cwd,
     exclude: (name) => name === 'node_modules',
+  };
+  let glob = new Glob(patterns, globOptions);
+
+  // Expand plain directory arguments into a recursive search for test files
+  // within them. A pattern with no glob magic that resolves to an existing
+  // directory (e.g. `node --test test/`) would otherwise match the directory
+  // itself and then be spawned as a test file, failing with MODULE_NOT_FOUND.
+  // This restores the directory-argument behavior that was documented and
+  // supported before test discovery moved to globbing.
+  // Refs: https://github.com/nodejs/node/issues/64555
+  let didExpandDirectory = false;
+  const expandedPatterns = ArrayPrototypeMap(patterns, (pattern, index) => {
+    if (glob.matchers[index].hasMagic()) {
+      return pattern;
+    }
+    let stats;
+    try {
+      stats = statSync(resolve(cwd, pattern));
+    } catch {
+      return pattern;
+    }
+    if (stats.isDirectory()) {
+      didExpandDirectory = true;
+      return join(pattern, kDefaultPattern);
+    }
+    return pattern;
   });
+  if (didExpandDirectory) {
+    glob = new Glob(expandedPatterns, globOptions);
+  }
+
   const results = glob.globSync();
 
   if (hasUserSuppliedPattern && results.length === 0 && ArrayPrototypeEvery(glob.matchers, (m) => !m.hasMagic())) {

test/parallel/test-runner-cli.js

@@ -161,6 +161,34 @@ for (const isolation of ['none', 'process']) {
     assert.strictEqual(child.signal, null);
   }
 
+  {
+    // A directory argument recursively runs the test files inside it, the same
+    // as running from that directory. Both the bare and trailing-slash forms
+    // are supported. Refs: https://github.com/nodejs/node/issues/64555
+    for (const dir of ['default-behavior', 'default-behavior/']) {
+      const args = [
+        '--test',
+        '--test-reporter=tap',
+        `--test-isolation=${isolation}`,
+        dir,
+      ];
+      const child = spawnSync(process.execPath, args, { cwd: testFixtures });
+
+      assert.strictEqual(child.stderr.toString(), '');
+      const stdout = child.stdout.toString();
+      assert.match(stdout, /ok 1 - this should pass/);
+      assert.match(stdout, /not ok 2 - this should fail/);
+      assert.match(stdout, /ok 3 - subdir.+subdir_test\.js/);
+      assert.match(stdout, /ok 4 - this should pass/);
+      assert.match(stdout, /ok 5 - this should be skipped/);
+      assert.match(stdout, /ok 6 - this should be executed/);
+      // node_modules is still excluded when a directory is expanded.
+      assert.doesNotMatch(stdout, /test-nm\.js/);
+      assert.strictEqual(child.status, 1);
+      assert.strictEqual(child.signal, null);
+    }
+  }
+
   {
     // Test combined stream outputs
     const args = [