Prevent Call to end() on null

build/baseline-7.4.neon

@@ -18,10 +18,6 @@ parameters:
 			message: "#^Class PHPStan\\\\Parallel\\\\Process has an uninitialized property \\$process\\. Give it default value or assign it in the constructor\\.$#"
 			count: 1
 			path: ../src/Parallel/Process.php
-		-
-			message: "#^Class PHPStan\\\\Parallel\\\\Process has an uninitialized property \\$in\\. Give it default value or assign it in the constructor\\.$#"
-			count: 1
-			path: ../src/Parallel/Process.php
 		-
 			message: "#^Class PHPStan\\\\PhpDoc\\\\ResolvedPhpDocBlock has an uninitialized property \\$phpDocNodes\\. Give it default value or assign it in the constructor\\.$#"
 			count: 1

src/Parallel/Process.php

@@ -21,7 +21,7 @@ class Process
 
 	public \React\ChildProcess\Process $process;
 
-	private WritableStreamInterface $in;
+	private ?WritableStreamInterface $in = null;
 
 	/** @var resource */
 	private $stdOut;
@@ -106,6 +106,9 @@ private function cancelTimer(): void
 	public function request(array $data): void
 	{
 		$this->cancelTimer();
+		if ($this->in === null) {
+			throw new ShouldNotHappenException();
+		}
 		$this->in->write($data);
 		$this->timer = $this->loop->addTimer($this->timeoutSeconds, function (): void {
 			$onError = $this->onError;
@@ -124,6 +127,10 @@ public function quit(): void
 			$pipe->close();
 		}
 
+		if ($this->in === null) {
+			return;
+		}
+
 		$this->in->end();
 	}