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

After the write triggers a restart of the grandchild, the newly spawned second grandchild can post another 'script ready' message before the stdout from the first grandchild is relayed by the watcher and processed by this parent process to kill the watcher. If we write again and trigger another restart, we can end up in an infinite loop and never receive the stdout of the grandchildren in time. Only write once to verify the first grandchild process receives the expected signal. We don't care about the subsequent grandchild processes. PR-URL: #60443 Refs: #60297 Refs: #60391 Reviewed-By: Luigi Pinca <[email protected]> Reviewed-By: Moshe Atlow <[email protected]> Reviewed-By: Darshan Sen <[email protected]>

Author: joyeecheung

test/fixtures/kill-signal-for-watch.js

@@ -1,4 +1,10 @@
-process.on('SIGTERM',()=>{console.log('__SIGTERM received__');process.exit();});
-process.on('SIGINT',()=>{console.log('__SIGINT received__');process.exit();});
-process.send('script ready');
+process.on('SIGTERM',()=>{
+console.log(`__SIGTERM received__ ${process.pid}`);
+process.exit();
+});
+process.on('SIGINT',()=>{
+console.log(`__SIGINT received__ ${process.pid}`);
+process.exit();
+});
+process.send(`script ready ${process.pid}`);
 setTimeout(()=>{},100_000);

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

@@ -26,20 +26,37 @@ const child = spawn(
 );
 
 letstdout='';
+letfirstGrandchildPid;
 child.stdout.on('data',(data)=>{
-stdout+=`${data}`;
-if(/__(SIGINT|SIGTERM)received__/.test(stdout)){
+constdataStr=data.toString();
+console.log(`[STDOUT] ${dataStr}`);
+stdout+=`${dataStr}`;
+constmatch=dataStr.match(/__(SIGINT|SIGTERM)received__(\d+)/);
+if(match&&match[2]===firstGrandchildPid){
+console.log(`[PARENT] Sending kill signal to watcher process: ${child.pid}`);
 child.kill();
 }
 });
 
+// After the write triggers a restart of the grandchild, the newly spawned second
+// grandchild can post another 'script ready' message before the stdout from the first
+// grandchild is relayed by the watcher and processed by this parent process to kill
+// the watcher. If we write again and trigger another restart, we can
+// end up in an infinite loop and never receive the stdout of the grandchildren in time.
+// Only write once to verify the first grandchild process receives the expected signal.
+// We don't care about the subsequent grandchild processes.
 child.on('message',(msg)=>{
-if(msg==='script ready'){
-writeFileSync(indexPath,indexContents);
+console.log(`[MESSAGE]`,msg);
+if(!firstGrandchildPid&&typeofmsg==='string'){
+constmatch=msg.match(/scriptready(\d+)/);
+if(match){
+firstGrandchildPid=match[1];// This is the first grandchild
+writeFileSync(indexPath,indexContents);
+}
 }
 });
 
 awaitonce(child,'exit');
 
-assert.match(stdout,/__SIGTERMreceived__/);
-assert.doesNotMatch(stdout,/__SIGINTreceived__/);
+assert.match(stdout,newRegExp(`__SIGTERM received__${firstGrandchildPid}`));
+assert.doesNotMatch(stdout,newRegExp(`__SIGINT received__${firstGrandchildPid}`));

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

@@ -27,20 +27,40 @@ const child = spawn(
 );
 
 letstdout='';
+letfirstGrandchildPid;
 child.stdout.on('data',(data)=>{
-stdout+=`${data}`;
-if(/__(SIGINT|SIGTERM)received__/.test(stdout)){
+constdataStr=data.toString();
+console.log(`[STDOUT] ${dataStr}`);
+stdout+=`${dataStr}`;
+constmatch=dataStr.match(/__(SIGINT|SIGTERM)received__(\d+)/);
+if(match&&match[2]===firstGrandchildPid){
+console.log(`[PARENT] Sending kill signal to watcher process: ${child.pid}`);
 child.kill();
 }
 });
 
+// After the write triggers a restart of the grandchild, the newly spawned second
+// grandchild can post another 'script ready' message before the stdout from the first
+// grandchild is relayed by the watcher and processed by this parent process to kill
+// the watcher. If we write again and trigger another restart, we can
+// end up in an infinite loop and never receive the stdout of the grandchildren in time.
+// Only write once to verify the first grandchild process receives the expected signal.
+// We don't care about the subsequent grandchild processes.
 child.on('message',(msg)=>{
-if(msg==='script ready'){
-writeFileSync(indexPath,indexContents);
+console.log(`[MESSAGE]`,msg);
+if(!firstGrandchildPid&&typeofmsg==='string'){
+constmatch=msg.match(/scriptready(\d+)/);
+if(match){
+firstGrandchildPid=match[1];// This is the first grandchild
+writeFileSync(indexPath,indexContents);
+}
 }
 });
 
 awaitonce(child,'exit');
 
-assert.match(stdout,/__SIGINTreceived__/);
-assert.doesNotMatch(stdout,/__SIGTERMreceived__/);
+// The second grandchild, if there is one, could receive SIGTERM if it's killed as a
+// consequence of the parent being killed in this process instead of being killed by the
+// parent for file changes. Here we only care about the first grandchild.
+assert.match(stdout,newRegExp(`__SIGINT received__ ${firstGrandchildPid}`));
+assert.doesNotMatch(stdout,newRegExp(`__SIGTERM received__ ${firstGrandchildPid}`));