fix(node): add workaround for handling sub processes in node:node exe…

…cutor (#10292)

In Nx 15, we plan to clean up runExecutor and implement proper process handling in runExecutor
upstream. This is a workaround that fix some racing-condition in node:node exexecutor downstream

ISSUES CLOSED: #9305

packages/node/src/executors/node/node.impl.ts

@@ -8,11 +8,14 @@ import {
 } from '@nrwl/devkit';
 import { calculateProjectDependencies } from '@nrwl/workspace/src/utilities/buildable-libs-utils';
 import { ChildProcess, fork } from 'child_process';
+import { HashingImpl } from 'nx/src/hasher/hashing-impl';
 import * as treeKill from 'tree-kill';
 import { promisify } from 'util';
 import { InspectType, NodeExecutorOptions } from './schema';
 
-let subProcess: ChildProcess = null;
+const hasher = new HashingImpl();
+const processMap = new Map<string, ChildProcess>();
+const hashedMap = new Map<string[], string>();
 
 export interface ExecutorEvent {
   outfile: string;
@@ -24,15 +27,15 @@ export async function* nodeExecutor(
   context: ExecutorContext
 ) {
   process.on('SIGTERM', async () => {
-    await killCurrentProcess();
+    await killCurrentProcess(options, 'SIGTERM');
     process.exit(128 + 15);
   });
   process.on('SIGINT', async () => {
-    await killCurrentProcess();
+    await killCurrentProcess(options, 'SIGINT');
     process.exit(128 + 2);
   });
   process.on('SIGHUP', async () => {
-    await killCurrentProcess();
+    await killCurrentProcess(options, 'SIGHUP');
     process.exit(128 + 1);
   });
 
@@ -84,11 +87,16 @@ async function runProcess(
   options: NodeExecutorOptions,
   mappings: { [project: string]: string }
 ) {
-  subProcess = fork(
+  const execArgv = getExecArgv(options);
+
+  const hashed = hasher.hashArray(execArgv.concat(options.args));
+  hashedMap.set(options.args, hashed);
+
+  const subProcess = fork(
     joinPathFragments(__dirname, 'node-with-require-overrides'),
     options.args,
     {
-      execArgv: getExecArgv(options),
+      execArgv,
       stdio: 'inherit',
       env: {
         ...process.env,
@@ -98,6 +106,8 @@ async function runProcess(
     }
   );
 
+  processMap.set(hashed, subProcess);
+
   if (!options.watch) {
     return new Promise<void>((resolve, reject) => {
       subProcess.on('exit', (code) => {
@@ -136,7 +146,7 @@ async function handleBuildEvent(
 ) {
   // Don't kill previous run unless new build is successful.
   if (options.watch && event.success) {
-    await killCurrentProcess();
+    await killCurrentProcess(options);
   }
 
   if (event.success) {
@@ -147,11 +157,24 @@ async function handleBuildEvent(
 const promisifiedTreeKill: (pid: number, signal: string) => Promise<void> =
   promisify(treeKill);
 
-async function killCurrentProcess() {
-  if (!subProcess) return;
+async function killCurrentProcess(
+  options: NodeExecutorOptions,
+  signal: string = 'SIGTERM'
+) {
+  const currentProcessKey = hashedMap.get(options.args);
+  if (!currentProcessKey) return;
+
+  const currentProcess = processMap.get(currentProcessKey);
+  if (!currentProcess) return;
 
   try {
-    await promisifiedTreeKill(subProcess.pid, 'SIGTERM');
+    await promisifiedTreeKill(currentProcess.pid, signal);
+
+    // if the currentProcess.killed is false, invoke kill()
+    // to properly send the signal to the process
+    if (!currentProcess.killed) {
+      currentProcess.kill(signal as NodeJS.Signals);
+    }
   } catch (err) {
     if (Array.isArray(err) && err[0] && err[2]) {
       const errorMessage = err[2];
@@ -160,7 +183,8 @@ async function killCurrentProcess() {
       logger.error(err.message);
     }
   } finally {
-    subProcess = null;
+    processMap.delete(currentProcessKey);
+    hashedMap.delete(options.args);
   }
 }