test: fix flaky test-watch-mode-kill-signal-*

This should only be triggered once. When the write
triggers a restart of the child, the newly spawned
child can post another 'script ready' message, and if
we write again and trigger another restart we can
end up in an infinite loop.

Author: joyeecheung

test/parallel/parallel.status

@@ -154,3 +154,8 @@ test-cluster-primary-error: PASS, FLAKY
 [$arch==loong64]
 # https://github.com/nodejs/node/issues/51662
 test-http-correct-hostname: SKIP
+
+[$system==macos || $system=win32 || ($system==linux && $arch==s390x) || ($system==linux && $arch==arm64)]
+# https://github.com/nodejs/node/issues/60297
+test-watch-mode-kill-signal-default: PASS, FLAKY
+test-watch-mode-kill-signal-override: PASS, FLAKY

test/parallel/test-watch-mode-kill-signal-default.mjs

@@ -27,15 +27,25 @@ const child = spawn(
 
 let stdout = '';
 child.stdout.on('data', (data) => {
-  stdout += `${data}`;
+  let dataStr = data.toString();
+  console.log(`[STDOUT] ${dataStr}`);
+  stdout += `${dataStr}`;
   if (/__(SIGINT|SIGTERM) received__/.test(stdout)) {
+    console.log(`[PARENT] Sending kill signal to child process: ${child.pid}`);
     child.kill();
   }
 });
 
+// This should only be triggered once. When the write triggers a restart of the
+// child, the newly spawned child can post another 'script ready' message, and if
+// we write again and trigger another restart we can end up in an infinite loop.
+let written = false;
 child.on('message', (msg) => {
+  console.log(`[MESSAGE]`, msg);
   if (msg === 'script ready') {
+    if (written) return;
     writeFileSync(indexPath, indexContents);
+    written = true;
   }
 });
 

test/parallel/test-watch-mode-kill-signal-override.mjs

@@ -28,15 +28,25 @@ const child = spawn(
 
 let stdout = '';
 child.stdout.on('data', (data) => {
-  stdout += `${data}`;
+  let dataStr = data.toString();
+  console.log(`[STDOUT] ${dataStr}`);
+  stdout += `${dataStr}`;
   if (/__(SIGINT|SIGTERM) received__/.test(stdout)) {
+    console.log(`[PARENT] Sending kill signal to child process: ${child.pid}`);
     child.kill();
   }
 });
 
+// This should only be triggered once. When the write triggers a restart of the
+// child, the newly spawned child can post another 'script ready' message, and if
+// we write again and trigger another restart we can end up in an infinite loop.
+let written = false;
 child.on('message', (msg) => {
+  console.log(`[MESSAGE]`, msg);
   if (msg === 'script ready') {
+    if (written) return;
     writeFileSync(indexPath, indexContents);
+    written = true;
   }
 });