Make Psalm happy

Author: sebastianbergmann

src/Util/Printer.php

@@ -24,7 +24,7 @@ class Printer
     protected $autoFlush = false;
 
     /**
-     * @var resource
+     * @var resource|closed-resource
      */
     protected $out;
 
@@ -77,6 +77,8 @@ public function __construct($out = null)
     public function flush(): void
     {
         if ($this->out && \strncmp($this->outTarget, 'php://', 6) !== 0) {
+            \assert(\is_resource($this->out));
+
             \fclose($this->out);
         }
     }
@@ -91,6 +93,8 @@ public function flush(): void
     public function incrementalFlush(): void
     {
         if ($this->out) {
+            \assert(\is_resource($this->out));
+
             \fflush($this->out);
         } else {
             \flush();
@@ -100,6 +104,8 @@ public function incrementalFlush(): void
     public function write(string $buffer): void
     {
         if ($this->out) {
+            \assert(\is_resource($this->out));
+
             \fwrite($this->out, $buffer);
 
             if ($this->autoFlush) {