test_runner: detect only tests when isolation is off

This commit updates the way the test runner processes 'only'
tests when process-based test isolation is disabled. The
--test-only flag is no longer necessary in this scenario. The
test runner will automatically detect 'only' tests and apply the
appropriate filtering.

PR-URL: #54832
Reviewed-By: Chemi Atlow <chemi@atlow.co.il>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Moshe Atlow <moshe@atlow.co.il>

doc/api/cli.md

@@ -2336,7 +2336,7 @@ changes:
 -->
 
 Configures the test runner to only execute top level tests that have the `only`
-option set.
+option set. This flag is not necessary when test isolation is disabled.
 
 ### `--test-reporter`
 

doc/api/test.md

@@ -229,10 +229,10 @@ const { describe, it } = require('node:test');
 
 ## `only` tests
 
-If Node.js is started with the [`--test-only`][] command-line option, it is
-possible to skip all tests except for a selected subset by passing
-the `only` option to the tests that should run. When a test with the `only`
-option is set, all subtests are also run.
+If Node.js is started with the [`--test-only`][] command-line option, or test
+isolation is disabled, it is possible to skip all tests except for a selected
+subset by passing the `only` option to the tests that should run. When a test
+with the `only` option is set, all subtests are also run.
 If a suite has the `only` option set, all tests within the suite are run,
 unless it has descendants with the `only` option set, in which case only those
 tests are run.

lib/internal/test_runner/harness.js

@@ -38,7 +38,8 @@ function createTestTree(rootTestOptions, globalOptions) {
  const buildPhaseDeferred = createDeferredPromise();
  const isFilteringByName = globalOptions.testNamePatterns ||
  globalOptions.testSkipPatterns;
- const isFilteringByOnly = globalOptions.only;
+ const isFilteringByOnly = globalOptions.only || (globalOptions.isTestRunner &&
+ globalOptions.isolation === 'none');
  const harness = {
  __proto__: null,
  buildPromise: buildPhaseDeferred.promise,

test/parallel/test-runner-no-isolation-filtering.js

@@ -45,10 +45,8 @@ test('works with --test-name-pattern', () => {
 
  assert.strictEqual(child.status, 0);
  assert.strictEqual(child.signal, null);
- assert.match(stdout, /# tests 1/);
+ assert.match(stdout, /# tests 0/);
  assert.match(stdout, /# suites 0/);
- assert.match(stdout, /# pass 1/);
- assert.match(stdout, /ok 1 - test one/);
 });
 
 test('works with --test-skip-pattern', () => {

test/parallel/test-runner-no-isolation-hooks.mjs

@@ -30,15 +30,6 @@ const order = [
  'afterEach one: suite one - test',
  'afterEach two: suite one - test',
 
- 'beforeEach(): global',
- 'beforeEach one: test one',
- 'beforeEach two: test one',
- 'test one',
-
- 'afterEach(): global',
- 'afterEach one: test one',
- 'afterEach two: test one',
-
  'before suite two: suite two',
  'beforeEach(): global',
  'beforeEach one: suite two - test',