fix(pidExists): handle Windows-specific error codes for process existence check

mceachen · mceachen · commit e7248ce8f45d · 2025-08-21T14:48:27.000-07:00
diff --git a/src/Pids.ts b/src/Pids.ts
@@ -1,3 +1,5 @@
+import { isWin } from "./Platform";
+
 /**
  * @param {number} pid process id. Required.
  * @returns boolean true if the given process id is in the local process
@@ -15,6 +17,13 @@ export function pidExists(pid: number | undefined): boolean {
     // exist. EPERM means it _does_ exist!
     if ((err as NodeJS.ErrnoException)?.code === "EPERM") return true;
 
+    // On Windows, some error codes might indicate the process is terminating
+    // but hasn't fully exited yet. Treat these as "not existing" to avoid
+    // race conditions during shutdown.
+    if (isWin && (err as NodeJS.ErrnoException)?.code === "EINVAL") {
+      return false;
+    }
+
     // failed to get priority--assume the pid is gone.
     return false;
   }
