Support local file instance as output file instead of stdout

Author: robgridley

src/Ghostscript.php

@@ -2,10 +2,10 @@
 
 namespace RobGridley\Ghostscript;
 
-use Symfony\Component\Process\Process;
 use RobGridley\Ghostscript\Contracts\Device;
-use RobGridley\Ghostscript\Contracts\LocalFile;
 use RobGridley\Ghostscript\Contracts\DownScaling;
+use RobGridley\Ghostscript\Contracts\LocalFile;
+use Symfony\Component\Process\Process;
 
 class Ghostscript
 {
@@ -175,9 +175,10 @@ public function setFitPage(int $width, int $height)
      *
      * @param LocalFile $file
      * @param int $page
+     * @param LocalFile|null $outputFile
      * @return string
      */
-    public function convert(LocalFile $file, int $page = 1): string
+    public function convert(LocalFile $file, int $page = 1, LocalFile $outputFile = null): string
     {
         $command[] = $this->path;
         array_push($command, ...$this->device->getArguments());
@@ -205,7 +206,11 @@ public function convert(LocalFile $file, int $page = 1): string
         $command[] = '-dBATCH';
         $command[] = '-dNOPAUSE';
         $command[] = '-dSAFER';
-        $command[] = '-sOutputFile=%stdout';
+        if (is_null($outputFile)) {
+            $command[] = '-sOutputFile=%stdout';
+        } else {
+            $command[] = "-sOutputFile={$outputFile->getLocalPath()}";
+        }
         $command[] = '-sstdout=%stderr';
         $command[] = '-q';
         $command[] = $file->getLocalPath();

src/VirtualFile.php

@@ -2,8 +2,8 @@
 
 namespace RobGridley\Ghostscript;
 
-use RuntimeException;
 use RobGridley\Ghostscript\Contracts\LocalFile;
+use RuntimeException;
 
 class VirtualFile implements LocalFile
 {
@@ -17,16 +17,18 @@ class VirtualFile implements LocalFile
     /**
      * Create a new temp file instance.
      *
-     * @param string|array|resource $data
+     * @param string|array|resource|null $data
      */
-    public function __construct($data)
+    public function __construct($data = null)
     {
         if (false === $path = tempnam(sys_get_temp_dir(), 'gs')) {
             throw new RuntimeException('Failed to create the temp file');
         }
 
-        if (false === file_put_contents($path, $data)) {
-            throw new RuntimeException('Failed to write data to the temp file');
+        if (!is_null($data)) {
+            if (false === file_put_contents($path, $data)) {
+                throw new RuntimeException('Failed to write data to the temp file');
+            }
         }
 
         $this->path = $path;