Wrap the socket creation in a function

tests/Feature/EnvironmentTest.php

@@ -21,13 +21,23 @@ public function it_detects_a_port_conflict()
         $environment = app(Environment::class);
         $this->assertTrue($environment->portIsAvailable($port));
 
+        $this->withFakeProcess($port, fn() => (
+            $this->assertFalse($environment->portIsAvailable($port))
+        ));
+    }
+
+    private function withFakeProcess(int $port, $callback)
+    {
         $socket = socket_create(domain: AF_INET, type: SOCK_STREAM, protocol: SOL_TCP);
         assert($socket !== false, 'Was not able to create a socket.');
         socket_set_option($socket, SOL_SOCKET, SO_REUSEADDR, 1);
         assert(socket_bind($socket, 'localhost', $port) !== false, "Was not able to bind socket to port {$port}");
         assert(socket_listen($socket, backlog: 5));
 
-        $this->assertFalse($environment->portIsAvailable($port));
-        socket_close($socket);
+        try {
+            $callback();
+        } finally {
+            socket_close($socket);
+        }
     }
 }