test: fix test-run-watch flakiness

Signed-off-by: Antoine du Hamel <duhamelantoine1995@gmail.com>

Author: aduh95

test/common/watch.js

@@ -2,7 +2,7 @@
 const common = require('./index.js');
 const tmpdir = require('./tmpdir.js');
 const fixtures = require('./fixtures.js');
-const { writeFileSync, readdirSync, readFileSync, renameSync, unlinkSync } = require('node:fs');
+const { writeFileSync, renameSync, unlinkSync, cpSync } = require('node:fs');
 const { spawn } = require('node:child_process');
 const { once } = require('node:events');
 const assert = require('node:assert');
@@ -37,14 +37,7 @@ const fixtureContent = {};
 
 function refreshForTestRunnerWatch() {
   tmpdir.refresh();
-  const files = readdirSync(fixtures.path('test-runner-watch'));
-  for (const file of files) {
-    const src = fixtures.path('test-runner-watch', file);
-    const dest = tmpdir.resolve(file);
-    fixturePaths[file] = dest;
-    fixtureContent[file] = readFileSync(src, 'utf8');
-    writeFileSync(dest, fixtureContent[file]);
-  }
+  cpSync(fixtures.path('test-runner-watch'), tmpdir.path, { recursive: true });
 }
 
 async function performFileOperation(operation, useRunApi, timeout = 1000) {

test/test-runner/test-run-watch-cwd-isolation-none-argv.mjs

@@ -2,7 +2,8 @@
 // parent process argv when spawning the watch child.
 import * as common from '../common/index.mjs';
 import assert from 'node:assert';
-import { writeFileSync } from 'node:fs';
+import { setTimeout } from 'node:timers/promises';
+import { writeFile } from 'node:fs/promises';
 import { join } from 'node:path';
 import { run } from 'node:test';
 import tmpdir from '../common/tmpdir.js';
@@ -11,31 +12,36 @@ import { skipIfNoWatch } from '../common/watch.js';
 skipIfNoWatch();
 tmpdir.refresh();
 
-writeFileSync(join(tmpdir.path, 'test.js'), `
+await writeFile(join(tmpdir.path, 'test.js'), `
 const test = require('node:test');
 
 test('test ran from cwd', () => {});
 `);
 
+// Add some delay to ensure the OS sends the FS events before watch mode is started.
+await setTimeout(common.platformTimeout(100));
+
 const passed = [];
 const controller = new AbortController();
 const stream = run({
   cwd: tmpdir.path,
   watch: true,
   signal: controller.signal,
   isolation: 'none',
-}).on('data', function({ type }) {
-  if (type === 'test:watch:drained') {
-    stream.removeAllListeners('test:fail');
-    stream.removeAllListeners('test:pass');
-    controller.abort();
-  }
+}).on('data', ({ type }) => {
+  if (type !== 'test:watch:drained') return;
+
+  stream.removeAllListeners('test:fail');
+  stream.removeAllListeners('test:pass');
+  controller.abort();
 });
 
-stream.on('test:fail', common.mustNotCall());
-stream.on('test:pass', common.mustCall((data) => passed.push(data.name), 1));
-// eslint-disable-next-line no-unused-vars
-for await (const _ of stream);
+stream.on('test:watch:restarted', common.mustNotCall('test:watch:restarted'));
+stream.on('test:fail', common.mustNotCall('test:fail'));
+stream.on('test:pass', common.mustCall((data) => passed.push(data.name)));
+
+// eslint-disable-next-line no-empty-pattern
+for await (const {} of stream);
 
 // Validate the expected test ran by name:
 assert.deepStrictEqual(passed, ['test ran from cwd']);

test/test-runner/test-run-watch-cwd-isolation-none.mjs

@@ -1,27 +1,29 @@
 // Test run({ watch: true, cwd, isolation: 'none' }) runs with different cwd while in watch mode and isolation none
 import * as common from '../common/index.mjs';
+import * as fixtures from '../common/fixtures.mjs';
+import { setTimeout } from 'node:timers/promises';
 import { run } from 'node:test';
-import tmpdir from '../common/tmpdir.js';
 import { refreshForTestRunnerWatch, skipIfNoWatch } from '../common/watch.js';
 
 skipIfNoWatch();
-refreshForTestRunnerWatch();
 
 const controller = new AbortController();
 const stream = run({
-  cwd: tmpdir.path,
+  cwd: fixtures.path('test-runner-watch'),
   watch: true,
   signal: controller.signal,
   isolation: 'none',
-}).on('data', function({ type }) {
-  if (type === 'test:watch:drained') {
-    stream.removeAllListeners('test:fail');
-    stream.removeAllListeners('test:pass');
-    controller.abort();
-  }
+}).on('data', ({ type }) => {
+  if (type !== 'test:watch:drained') return;
+
+  stream.removeAllListeners('test:fail');
+  stream.removeAllListeners('test:pass');
+  controller.abort();
 });
 
-stream.on('test:fail', common.mustNotCall());
-stream.on('test:pass', common.mustCall(1));
-// eslint-disable-next-line no-unused-vars
-for await (const _ of stream);
+stream.on('test:watch:restarted', common.mustNotCall('test:watch:restarted'));
+stream.on('test:fail', common.mustNotCall('test:fail'));
+stream.on('test:pass', common.mustCall());
+
+// eslint-disable-next-line no-empty-pattern
+for await (const {} of stream);