test: fix flaky test-inspector-connect-main-thread

Previously, the test waited for a (any) message from the workers, and then attached another event listener to a specific kind of message. However, it was possible that the second listener was attached after the Worker had already exited, thus never receiving the message it was supposed to receive. (This is the race condition here – usually, the Worker thread would exit *after* the second listener was attached.) Solve this by keeping a single `'message'` event listener attached to the worker instance during its entire lifetime. Fixes: #31226 PR-URL: #31637 Reviewed-By: Eugene Ostroukhov <[email protected]> Reviewed-By: Rich Trott <[email protected]>

Author: addaleax

test/parallel/test-inspector-connect-main-thread.js

@@ -50,28 +50,19 @@ function startWorker(skipChild, sharedBuffer){
 console.error(e);
 throwe;
 });
-worker.once('message',(m)=>{
+// Add 2 promises to the worker, one resolved when a message with a
+// .doConsoleLog property is received and one resolved when a .messagesSent
+// property is received.
+letresolveConsoleRequest;
+letresolveMessagesSent;
+worker.onConsoleRequest=
+newPromise((resolve)=>resolveConsoleRequest=resolve);
+worker.onMessagesSent=
+newPromise((resolve)=>resolveMessagesSent=resolve);
+worker.on('message',(m)=>{
 resolve(worker);
-});
-});
-}
-
-functionwaitForConsoleRequest(worker){
-returnnewPromise((resolve)=>{
-worker.on('message',({ doConsoleLog })=>{
-if(doConsoleLog){
-resolve();
-}
-});
-});
-}
-
-functionwaitForMessagesSent(worker){
-returnnewPromise((resolve)=>{
-worker.on('message',({ messagesSent })=>{
-if(messagesSent){
-resolve(messagesSent);
-}
+if(m.doConsoleLog)resolveConsoleRequest();
+if(m.messagesSent)resolveMessagesSent(m.messagesSent);
 });
 });
 }
@@ -107,10 +98,9 @@ async function main(){
 constarrayBuffer=newUint8Array(sharedBuffer);
 arrayBuffer[0]=1;
 constworker=awaitstartWorker(false,sharedBuffer);
-waitForConsoleRequest(worker).then(doConsoleLog.bind(null,arrayBuffer));
-constworkerDonePromise=waitForMessagesSent(worker);
+worker.onConsoleRequest.then(doConsoleLog.bind(null,arrayBuffer));
 assert.strictEqual(toDebug(),400);
-assert.deepStrictEqual(awaitworkerDonePromise,[
+assert.deepStrictEqual(awaitworker.onMessagesSent,[
 'Debugger.enable',
 'Runtime.enable',
 'Debugger.setBreakpointByUrl',
@@ -122,7 +112,7 @@ async function main(){
 asyncfunctionchildMain(){
 // Ensures the worker does not terminate too soon
 parentPort.on('message',()=>{});
-awaitwaitForMessagesSent(awaitstartWorker(true));
+await(awaitstartWorker(true)).onMessagesSent;
 constsession=newSession();
 session.connectToMainThread();
 awaitpost(session,'Debugger.enable');