From 7e0719cc0a85790217c2027a4dd59903caa1489c Mon Sep 17 00:00:00 2001
From: Jack Hsu <jack.hsu@gmail.com>
Date: Wed, 21 May 2025 13:09:30 -0400
Subject: [PATCH] fix(core): handle killing child processes of continuous tasks
 on Windows (#31296)

This PR fixes an issue where running `nx e2e <proj>` on Windows does not
kill the underlying dev/preview server when the e2e task ends.

Repro:
1. `npx create-nx-workspace@latest repro --preset=react-monorepo
--e2eTestRunner=playwright --appName=demo`
2. `cd repro && npx nx e2e demo-e2e`

This will leave the preview server running on port `4300`, and you have
to `netstat -ano | findstr :4300` to find the PID and kill it.

https://www.loom.com/share/fcbea53cdff543a98f4d4c8377027ee0

## Current Behavior
Continuous task does not kill the process correctly once discrete task
ends.

## Expected Behavior
Processes are killed correctly once task is done running.

## Related Issue(s)
<!-- Please link the issue being fixed so it gets closed when this is
merged. -->

Fixes #31235
---
 .../executors/run-commands/running-tasks.ts   | 20 +++++++------------
 1 file changed, 7 insertions(+), 13 deletions(-)

diff --git a/packages/nx/src/executors/run-commands/running-tasks.ts b/packages/nx/src/executors/run-commands/running-tasks.ts
index b3420c0e90..b755969328 100644
--- a/packages/nx/src/executors/run-commands/running-tasks.ts
+++ b/packages/nx/src/executors/run-commands/running-tasks.ts
@@ -359,21 +359,15 @@ class RunningNodeProcess implements RunningTask {
 
   kill(signal?: NodeJS.Signals): Promise<void> {
     return new Promise<void>((res, rej) => {
-      if (process.platform === 'win32') {
-        if (this.childProcess.kill(signal)) {
-          res();
+      treeKill(this.childProcess.pid, signal, (err) => {
+        // On Windows, tree-kill (which uses taskkill) may fail when the process or its child process is already terminated.
+        // Ignore the errors, otherwise we will log them unnecessarily.
+        if (err && process.platform !== 'win32') {
+          rej(err);
         } else {
-          rej('Unable to kill process');
+          res();
         }
-      } else {
-        treeKill(this.childProcess.pid, signal, (err) => {
-          if (err) {
-            rej(err);
-          } else {
-            res();
-          }
-        });
-      }
+      });
     });
   }