test: add new test for Configuration (#2915)

tests/ConfigurationTest.php

@@ -0,0 +1,31 @@
+<?php
+
+declare(strict_types=1);
+
+namespace RssBridge\Tests;
+
+use Configuration;
+use PHPUnit\Framework\TestCase;
+
+final class ConfigurationTest extends TestCase
+{
+    public function test()
+    {
+        putenv('RSSBRIDGE_system_timezone=Europe/Berlin');
+        Configuration::loadConfiguration();
+
+        // test nonsense
+        $this->assertSame(null, Configuration::getConfig('foobar', ''));
+        $this->assertSame(null, Configuration::getConfig('foo', 'bar'));
+        $this->assertSame(null, Configuration::getConfig('cache', ''));
+
+        // test value from env
+        $this->assertSame('Europe/Berlin', Configuration::getConfig('system', 'timezone'));
+
+        // test real values
+        $this->assertSame('file', Configuration::getConfig('cache', 'type'));
+        $this->assertSame(false, Configuration::getConfig('authentication', 'enable'));
+        $this->assertSame(true, Configuration::getConfig('admin', 'donations'));
+        $this->assertSame(1, Configuration::getConfig('error', 'report_limit'));
+    }
+}