Add openFile() method to FileHelper (#37)

src/FileHelper.php

@@ -16,6 +16,34 @@
  */
 class FileHelper
 {
+    /**
+     * Opens a file or URL.
+     *
+     * This method is similar to the PHP `fopen()` function, except that it suppresses the `E_WARNING`
+     * level error and throws the `\RuntimeException` exception if it can't open the file.
+     *
+     * @param string $filename The file or URL.
+     * @param string $mode The type of access.
+     * @param bool $useIncludePath Whether to search for a file in the include path.
+     * @param resource|null $context The stream context or `null`.
+     *
+     * @throws RuntimeException If the file could not be opened.
+     *
+     * @return resource The file pointer resource.
+     *
+     * @psalm-suppress PossiblyNullArgument
+     */
+    public static function openFile(string $filename, string $mode, bool $useIncludePath = false, $context = null)
+    {
+        $filePointer = @fopen($filename, $mode, $useIncludePath, $context);
+
+        if ($filePointer === false) {
+            throw new RuntimeException("The file \"{$filename}\" could not be opened.");
+        }
+
+        return $filePointer;
+    }
+
     /**
      * Creates a new directory.
      *

tests/FileHelperTest.php

@@ -12,6 +12,26 @@
  */
 final class FileHelperTest extends FileSystemTestCase
 {
+    public function testOpenFileWithFile(): void
+    {
+        $resource = FileHelper::openFile(tempnam($this->testFilePath, 'test'), 'rb', true);
+        $this->assertIsResource($resource);
+        fclose($resource);
+    }
+
+    public function testOpenFileWithUrl(): void
+    {
+        $resource = FileHelper::openFile('php://output', 'wb');
+        $this->assertIsResource($resource);
+        fclose($resource);
+    }
+
+    public function testOpenFileException(): void
+    {
+        $this->expectException(RuntimeException::class);
+        FileHelper::openFile('invalid://uri', 'rb');
+    }
+
     public function testCreateDirectory(): void
     {
         $basePath = $this->testFilePath;