tests: Use PSR-4-style namespaces (#2778)

We cannot yet switch to namespaces for RSS-Bridge itself but for tests we are not limited by BC.
It does not actually do anything since PHPUnit will search for the test files without the help of the autoloader but it still makes the directory cleaner.

tests/Formats/JsonFormatTest.php

@@ -0,0 +1,75 @@
+<?php
+/**
+ * JsonFormat - JSON Feed Version 1
+ * https://jsonfeed.org/version/1
+ */
+
+namespace RssBridge\Tests\Formats;
+
+use FormatFactory;
+use PHPUnit\Framework\TestCase;
+
+class JsonFormatTest extends TestCase {
+	const PATH_SAMPLES	= __DIR__ . '/samples/';
+	const PATH_EXPECTED	= __DIR__ . '/samples/expectedJsonFormat/';
+
+	private $sample;
+	private $format;
+	private $data;
+
+	/**
+	 * @dataProvider sampleProvider
+	 * @runInSeparateProcess
+	 */
+	public function testOutput($path) {
+		$this->setSample($path);
+		$this->initFormat();
+
+		$this->assertJsonStringEqualsJsonFile($this->sample->expected, $this->data);
+	}
+
+	public function sampleProvider() {
+		$samples = array();
+		foreach (glob(self::PATH_SAMPLES . '*.json') as $path) {
+			$samples[basename($path, '.json')] = array($path);
+		}
+		return $samples;
+	}
+
+	private function setSample($path) {
+		$data = json_decode(file_get_contents($path), true);
+		if (isset($data['meta']) && isset($data['items'])) {
+			if (!empty($data['server']))
+				$this->setServerVars($data['server']);
+
+			$items = array();
+			foreach($data['items'] as $item) {
+				$items[] = new \FeedItem($item);
+			}
+
+			$this->sample = (object)array(
+				'meta'		=> $data['meta'],
+				'items'		=> $items,
+				'expected'	=> self::PATH_EXPECTED . basename($path)
+			);
+		} else {
+			$this->fail('invalid test sample: ' . basename($path, '.json'));
+		}
+	}
+
+	private function setServerVars($list) {
+		$_SERVER = array_merge($_SERVER, $list);
+	}
+
+	private function initFormat() {
+		$formatFac = new FormatFactory();
+		$formatFac->setWorkingDir(PATH_LIB_FORMATS);
+		$this->format = $formatFac->create('Json');
+		$this->format->setItems($this->sample->items);
+		$this->format->setExtraInfos($this->sample->meta);
+		$this->format->setLastModified(strtotime('2000-01-01 12:00:00 UTC'));
+
+		$this->data = $this->format->stringify();
+		$this->assertNotNull(json_decode($this->data), 'invalid JSON output: ' . json_last_error_msg());
+	}
+}