Add symlink functionality

Author: sebastianfeldmann

src/Storage/File.php

@@ -119,4 +119,27 @@ private function checkDir(): void
             }
         }
     }
+
+    /**
+     * Determines if the given path is a symbolic link
+     *
+     * @return bool True if the path is a symbolic link, false otherwise.
+     */
+    public function isLink(): bool
+    {
+        return is_link($this->path);
+    }
+
+    /**
+     * Resolves and returns the target of a symbolic link
+     *
+     * @return string The resolved target of the symbolic link.
+     */
+    public function linkTarget(): string
+    {
+        if (!$this->isLink()) {
+            throw new RuntimeException('Not a symbolic link: ' . $this->path);
+        }
+        return (string)readlink($this->path);
+    }
 }

tests/unit/Storage/FileTest.php

@@ -14,6 +14,7 @@
 use Exception;
 use org\bovigo\vfs\vfsStream;
 use PHPUnit\Framework\TestCase;
+use RuntimeException;
 
 class FileTest extends TestCase
 {
@@ -63,6 +64,36 @@ public function testWrite(): void
         $this->assertTrue(unlink($path));
     }
 
+    /**
+     * Tests File::isLink
+     */
+    public function testIsLink(): void
+    {
+        $tmpDir = sys_get_temp_dir();
+        $link   = $tmpDir . '/fooLink';
+        $target = tempnam($tmpDir, 'bar');
+
+        symlink($target, $link);
+
+        $file = new File($link);
+        $this->assertTrue($file->isLink());
+        $this->assertEquals($target, $file->linkTarget());
+
+        $this->assertTrue(unlink($link));
+        $this->assertTrue(unlink($target));
+    }
+
+    /**
+     * Tests File::linkTarget
+     */
+    public function testLinkTarget(): void
+    {
+        $this->expectException(RuntimeException::class);
+
+        $file = new File(__FILE__);
+        $file->linkTarget();
+    }
+
     /**
      * Tests File::write
      */