feat: print name of changed file that triggers restart

lib/internal/main/watch_mode.js

@@ -169,11 +169,14 @@ async function stop(child) {
 
 let restarting = false;
 
-async function restart(child) {
+async function restart(child, trigger) {
   if (restarting) return;
   restarting = true;
   try {
     if (!kPreserveOutput) process.stdout.write(clear);
+    if (trigger) {
+      process.stdout.write(`${blue}Change detected in ${inspect(trigger)}${white}\n`);
+    }
     process.stdout.write(`${green}Restarting ${kCommandStr}${white}\n`);
     await stop(child);
     return start();
@@ -184,8 +187,8 @@ async function restart(child) {
 
 async function init() {
   let child = start();
-  const restartChild = async () => {
-    child = await restart(child);
+  const restartChild = async ({ trigger } = {}) => {
+    child = await restart(child, trigger);
   };
   watcher
     .on('changed', restartChild)

lib/internal/watch_mode/files_watcher.js

@@ -39,6 +39,7 @@ class FilesWatcher extends EventEmitter {
   #ownerDependencies = new SafeMap();
   #debounceOwners = new SafeSet();
   #debounceTimer;
+  #debounceTrigger;
   #debounce;
   #mode;
   #signal;
@@ -98,11 +99,13 @@ class FilesWatcher extends EventEmitter {
         this.#debounceOwners.add(owner);
       }
     }
+    this.#debounceTrigger = trigger;
     clearTimeout(this.#debounceTimer);
     this.#debounceTimer = setTimeout(() => {
       this.#debounceTimer = null;
-      this.emit('changed', { owners: this.#debounceOwners, eventType });
+      this.emit('changed', { owners: this.#debounceOwners, eventType, trigger: this.#debounceTrigger });
       this.#debounceOwners.clear();
+      this.#debounceTrigger = undefined;
     }, this.#debounce).unref();
   }
 
@@ -207,6 +210,7 @@ class FilesWatcher extends EventEmitter {
     clearTimeout(this.#debounceTimer);
     this.#debounceTimer = null;
     this.#debounceOwners.clear();
+    this.#debounceTrigger = undefined;
     this.#watchers.forEach(this.#unwatch);
     this.#watchers.clear();
     this.#filteredFiles.clear();

test/sequential/test-watch-mode-restart-esm-loading-error.mjs

@@ -120,6 +120,7 @@ try {
   const { stderr: stderr2, stdout: stdout2 } = await failedRestart;
   assert.match(stderr2, /SyntaxError: Invalid or unexpected token/);
   assert.deepStrictEqual(stdout2, [
+    `Change detected in ${inspect(file)}`,
     `Restarting ${inspect(file)}`,
     `Failed running ${inspect(file)}. Waiting for file changes before restarting...`,
   ]);
@@ -132,6 +133,7 @@ try {
   // Verify it recovered and ran successfully
   assert.strictEqual(stderr3, '');
   assert.deepStrictEqual(stdout3, [
+    `Change detected in ${inspect(file)}`,
     `Restarting ${inspect(file)}`,
     'hello again, world',
     `Completed running ${inspect(file)}. Waiting for file changes before restarting...`,

test/sequential/test-watch-mode-worker.mjs

@@ -19,6 +19,10 @@ function restart(file) {
   return () => clearInterval(timer);
 }
 
+function changeDetected(file) {
+  return `Change detected in ${inspect(file)}`;
+}
+
 let tmpFiles = 0;
 function createTmpFile(content = 'console.log(\'running\');', ext = '.js', basename = tmpdir.path) {
   const file = path.join(basename, `${tmpFiles++}${ext}`);
@@ -108,6 +112,7 @@ const w = new Worker(${JSON.stringify(worker)});
     assert.deepStrictEqual(stdout, [
       'worker running',
       `Completed running ${inspect(file)}. Waiting for file changes before restarting...`,
+      changeDetected(worker),
       `Restarting ${inspect(file)}`,
       'worker running',
       `Completed running ${inspect(file)}. Waiting for file changes before restarting...`,
@@ -142,6 +147,7 @@ const w = new Worker(${JSON.stringify(worker)});
     assert.deepStrictEqual(stdout, [
       'dep v1',
       `Completed running ${inspect(file)}. Waiting for file changes before restarting...`,
+      changeDetected(dep),
       `Restarting ${inspect(file)}`,
       'dep v1',
       `Completed running ${inspect(file)}. Waiting for file changes before restarting...`,
@@ -182,6 +188,7 @@ const w = new Worker(${JSON.stringify(worker)});
     assert.deepStrictEqual(stdout, [
       'sub-dep v1',
       `Completed running ${inspect(file)}. Waiting for file changes before restarting...`,
+      changeDetected(subDep),
       `Restarting ${inspect(file)}`,
       'sub-dep v1',
       `Completed running ${inspect(file)}. Waiting for file changes before restarting...`,
@@ -210,6 +217,7 @@ new Worker(new URL(${JSON.stringify(pathToFileURL(worker))}));
     assert.deepStrictEqual(stdout, [
       'worker running',
       `Completed running ${inspect(file)}. Waiting for file changes before restarting...`,
+      changeDetected(worker),
       `Restarting ${inspect(file)}`,
       'worker running',
       `Completed running ${inspect(file)}. Waiting for file changes before restarting...`,
@@ -244,6 +252,7 @@ new Worker(new URL(${JSON.stringify(pathToFileURL(worker))}));
     assert.deepStrictEqual(stdout, [
       'dep v1',
       `Completed running ${inspect(file)}. Waiting for file changes before restarting...`,
+      changeDetected(dep),
       `Restarting ${inspect(file)}`,
       'dep v1',
       `Completed running ${inspect(file)}. Waiting for file changes before restarting...`,
@@ -284,6 +293,7 @@ new Worker(new URL(${JSON.stringify(pathToFileURL(worker))}));
     assert.deepStrictEqual(stdout, [
       'sub-dep v1',
       `Completed running ${inspect(file)}. Waiting for file changes before restarting...`,
+      changeDetected(subDep),
       `Restarting ${inspect(file)}`,
       'sub-dep v1',
       `Completed running ${inspect(file)}. Waiting for file changes before restarting...`,

test/sequential/test-watch-mode.mjs

@@ -23,6 +23,10 @@ function restart(file, content = readFileSync(file)) {
   return () => clearInterval(timer);
 }
 
+function changeDetected(file) {
+  return `Change detected in ${inspect(file)}`;
+}
+
 let tmpFiles = 0;
 function createTmpFile(content = 'console.log("running");', ext = '.js', basename = tmpdir.path) {
   const file = path.join(basename, `${tmpFiles++}${ext}`);
@@ -198,6 +202,7 @@ describe('watch mode', { concurrency: !process.env.TEST_PARALLEL, timeout: 60_00
     assert.deepStrictEqual(stdout, [
       'running',
       `Completed running ${inspect(file)}. Waiting for file changes before restarting...`,
+      changeDetected(file),
       `Restarting ${inspect(file)}`,
       'running',
       `Completed running ${inspect(file)}. Waiting for file changes before restarting...`,
@@ -212,6 +217,7 @@ describe('watch mode', { concurrency: !process.env.TEST_PARALLEL, timeout: 60_00
     assert.deepStrictEqual(stdout, [
       'running',
       `Completed running ${inspect(file)}. Waiting for file changes before restarting...`,
+      changeDetected(file),
       `Restarting ${inspect(file)}`,
       'running',
       `Completed running ${inspect(file)}. Waiting for file changes before restarting...`,
@@ -233,6 +239,7 @@ describe('watch mode', { concurrency: !process.env.TEST_PARALLEL, timeout: 60_00
 
       assert.strictEqual(stderr, '');
       assert.deepStrictEqual(stdout, [
+        changeDetected(envFile),
         `Restarting ${inspect(jsFile)}`,
         'ENV: value2',
         `Completed running ${inspect(jsFile)}. Waiting for file changes before restarting...`,
@@ -258,6 +265,7 @@ describe('watch mode', { concurrency: !process.env.TEST_PARALLEL, timeout: 60_00
 
       assert.strictEqual(stderr, '');
       assert.deepStrictEqual(stdout, [
+        changeDetected(envFile),
         `Restarting ${inspect(jsFile)}`,
         'ENV: value1',
         'ENV2: newValue',
@@ -284,6 +292,7 @@ describe('watch mode', { concurrency: !process.env.TEST_PARALLEL, timeout: 60_00
 
       assert.strictEqual(stderr, '');
       assert.deepStrictEqual(stdout, [
+        changeDetected(envFile),
         `Restarting ${inspect(jsFile)}`,
         'ENV: value1',
         'ENV2: newValue',
@@ -327,6 +336,7 @@ describe('watch mode', { concurrency: !process.env.TEST_PARALLEL, timeout: 60_00
     assert.match(stderr, /Error: fails\r?\n/);
     assert.deepStrictEqual(stdout, [
       `Failed running ${inspect(file)}. Waiting for file changes before restarting...`,
+      changeDetected(file),
       `Restarting ${inspect(file)}`,
       `Failed running ${inspect(file)}. Waiting for file changes before restarting...`,
     ]);
@@ -346,6 +356,7 @@ describe('watch mode', { concurrency: !process.env.TEST_PARALLEL, timeout: 60_00
     assert.deepStrictEqual(stdout, [
       'running',
       `Completed running ${inspect(file)}. Waiting for file changes before restarting...`,
+      changeDetected(watchedFile),
       `Restarting ${inspect(file)}`,
       'running',
       `Completed running ${inspect(file)}. Waiting for file changes before restarting...`,
@@ -372,6 +383,7 @@ describe('watch mode', { concurrency: !process.env.TEST_PARALLEL, timeout: 60_00
     assert.match(stderr, /Error: Cannot find module/g);
     assert.deepStrictEqual(stdout, [
       `Failed running ${inspect(file)}. Waiting for file changes before restarting...`,
+      changeDetected(watchedFile),
       `Restarting ${inspect(file)}`,
       `Failed running ${inspect(file)}. Waiting for file changes before restarting...`,
     ]);
@@ -396,6 +408,7 @@ describe('watch mode', { concurrency: !process.env.TEST_PARALLEL, timeout: 60_00
     assert.match(stderr, /Error: Cannot find module/g);
     assert.deepStrictEqual(stdout, [
       `Failed running ${inspect(file)}. Waiting for file changes before restarting...`,
+      changeDetected(watchedFile),
       `Restarting ${inspect(file)}`,
       `Failed running ${inspect(file)}. Waiting for file changes before restarting...`,
     ]);
@@ -411,6 +424,7 @@ console.log("don't show me");`);
     assert.strictEqual(stderr, '');
     assert.deepStrictEqual(stdout, [
       'running',
+      changeDetected(file),
       `Restarting ${inspect(file)}`,
       'running',
     ]);
@@ -428,6 +442,7 @@ console.log(dependency);
     assert.deepStrictEqual(stdout, [
       '{}',
       `Completed running ${inspect(file)}. Waiting for file changes before restarting...`,
+      changeDetected(dependency),
       `Restarting ${inspect(file)}`,
       '{}',
       `Completed running ${inspect(file)}. Waiting for file changes before restarting...`,
@@ -446,6 +461,7 @@ console.log(dependency);
     assert.deepStrictEqual(stdout, [
       '{}',
       `Completed running ${inspect(file)}. Waiting for file changes before restarting...`,
+      changeDetected(dependency),
       `Restarting ${inspect(file)}`,
       '{}',
       `Completed running ${inspect(file)}. Waiting for file changes before restarting...`,
@@ -460,9 +476,11 @@ console.log(dependency);
     assert.deepStrictEqual(stdout, [
       'running',
       `Completed running ${inspect(file)}. Waiting for file changes before restarting...`,
+      changeDetected(file),
       `Restarting ${inspect(file)}`,
       'running',
       `Completed running ${inspect(file)}. Waiting for file changes before restarting...`,
+      changeDetected(file),
       `Restarting ${inspect(file)}`,
       'running',
       `Completed running ${inspect(file)}. Waiting for file changes before restarting...`,
@@ -483,6 +501,7 @@ console.log(values.random);
     assert.deepStrictEqual(stdout, [
       random,
       `Completed running ${inspect(`${file} --random ${random}`)}. Waiting for file changes before restarting...`,
+      changeDetected(file),
       `Restarting ${inspect(`${file} --random ${random}`)}`,
       random,
       `Completed running ${inspect(`${file} --random ${random}`)}. Waiting for file changes before restarting...`,
@@ -500,6 +519,7 @@ console.log(values.random);
     assert.deepStrictEqual(stdout, [
       'running',
       `Completed running ${inspect(file)}. Waiting for file changes before restarting...`,
+      changeDetected(file),
       `Restarting ${inspect(file)}`,
       'running',
       `Completed running ${inspect(file)}. Waiting for file changes before restarting...`,
@@ -520,6 +540,7 @@ console.log(values.random);
     assert.deepStrictEqual(stdout, [
       'running',
       `Completed running ${inspect(file)}. Waiting for file changes before restarting...`,
+      changeDetected(file),
       `Restarting ${inspect(file)}`,
       'running',
       `Completed running ${inspect(file)}. Waiting for file changes before restarting...`,
@@ -569,6 +590,7 @@ console.log(values.random);
     assert.deepStrictEqual(stdout, [
       'running',
       `Completed running ${inspect(file)}. Waiting for file changes before restarting...`,
+      changeDetected(file),
       `Restarting ${inspect(file)}`,
       'running',
       `Completed running ${inspect(file)}. Waiting for file changes before restarting...`,
@@ -584,6 +606,7 @@ console.log(values.random);
     assert.deepStrictEqual(stdout, [
       'running',
       `Completed running ${inspect(file)}. Waiting for file changes before restarting...`,
+      changeDetected(file),
       `Restarting ${inspect(file)}`,
       'running',
       `Completed running ${inspect(file)}. Waiting for file changes before restarting...`,
@@ -615,6 +638,7 @@ console.log(values.random);
       'hello',
       'running',
       `Completed running ${inspect(file)}. Waiting for file changes before restarting...`,
+      changeDetected(watchedFile),
       `Restarting ${inspect(file)}`,
       'hello',
       'running',
@@ -647,6 +671,7 @@ console.log(values.random);
       'hello',
       'running',
       `Completed running ${inspect(file)}. Waiting for file changes before restarting...`,
+      changeDetected(watchedFile),
       `Restarting ${inspect(file)}`,
       'hello',
       'running',
@@ -679,6 +704,7 @@ console.log(values.random);
       'hello',
       'running',
       `Completed running ${inspect(file)}. Waiting for file changes before restarting...`,
+      changeDetected(watchedFile),
       `Restarting ${inspect(file)}`,
       'hello',
       'running',
@@ -711,6 +737,7 @@ console.log(values.random);
       'hello',
       'running',
       `Completed running ${inspect(file)}. Waiting for file changes before restarting...`,
+      changeDetected(watchedFile),
       `Restarting ${inspect(file)}`,
       'hello',
       'running',
@@ -727,6 +754,7 @@ console.log(values.random);
     assert.deepStrictEqual(stdout, [
       'running',
       `Completed running ${inspect(file)}. Waiting for file changes before restarting...`,
+      changeDetected(file),
       `Restarting ${inspect(file)}`,
       'running',
       `Completed running ${inspect(file)}. Waiting for file changes before restarting...`,
@@ -752,6 +780,7 @@ console.log(values.random);
       'hello',
       'running',
       `Completed running ${inspect(file)}. Waiting for file changes before restarting...`,
+      changeDetected(file),
       `Restarting ${inspect(file)}`,
       'hello',
       'running',
@@ -832,6 +861,7 @@ process.on('message', (message) => {
     assert.deepStrictEqual(lines, [
       'running',
       'Received: first message',
+      changeDetected(file),
       `Restarting ${inspect(file)}`,
       'running',
       'Received: second message',
@@ -852,6 +882,7 @@ process.on('message', (message) => {
     assert.deepStrictEqual(stdout, [
       'running',
       `Completed running ${inspect(file)}. Waiting for file changes before restarting...`,
+      changeDetected(file),
       `Restarting ${inspect(file)}`,
       'running',
       `Completed running ${inspect(file)}. Waiting for file changes before restarting...`,
@@ -874,6 +905,7 @@ process.on('message', (message) => {
     assert.deepStrictEqual(stdout, [
       'running',
       `Completed running ${inspect(file)}. Waiting for file changes before restarting...`,
+      changeDetected(watchedFile),
       `Restarting ${inspect(file)}`,
       'running',
       `Completed running ${inspect(file)}. Waiting for file changes before restarting...`,
@@ -902,6 +934,7 @@ process.on('message', (message) => {
     assert.deepStrictEqual(stdout, [
       'running',
       `Completed running ${inspect(file)}. Waiting for file changes before restarting...`,
+      changeDetected(file),
       `Restarting ${inspect(file)}`,
       'running',
       `Completed running ${inspect(file)}. Waiting for file changes before restarting...`,