:octocat: file caching rework/cleanup

tests/QRCodeTest.php

@@ -14,6 +14,7 @@ use chillerlan\QRCode\{QROptions, QRCode};
 use chillerlan\QRCode\Output\{QRCodeOutputException, QROutputInterface};
 use PHPUnit\Framework\TestCase;
 use stdClass;
+use function file_get_contents;
 
 /**
  * Tests basic functions of the QRCode class
@@ -22,6 +23,7 @@ final class QRCodeTest extends TestCase{
 
 	private QRCode    $qrcode;
 	private QROptions $options;
+	private string    $builddir = __DIR__.'/../.build/output_test';
 
 	/**
 	 * invoke test instances
@@ -68,4 +70,28 @@ final class QRCodeTest extends TestCase{
 		$this->qrcode->setOptions($this->options)->render('test');
 	}
 
+	/**
+	 * Tests if an exception is thrown when trying to write a cache file to an invalid destination
+	 */
+	public function testSaveException():void{
+		$this->expectException(QRCodeOutputException::class);
+		$this->expectExceptionMessage('Cannot write data to cache file: /foo/bar.test');
+
+		$this->options->cachefile = '/foo/bar.test';
+
+		$this->qrcode->setOptions($this->options)->render('test');
+	}
+
+	/**
+	 * Tests if a cache file is properly saved in the given path
+	 */
+	public function testRenderToCacheFile():void{
+		$this->options->cachefile   = $this->builddir.'/test.cache.svg';
+		$this->options->imageBase64 = false;
+		// create the cache file
+		$data = $this->qrcode->setOptions($this->options)->render('test');
+
+		$this::assertSame($data, file_get_contents($this->options->cachefile));
+	}
+
 }