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/Actions/ActionImplementationTest.php

@@ -0,0 +1,59 @@
+<?php
+
+namespace RssBridge\Tests\Actions;
+
+use ActionAbstract;
+use ActionInterface;
+use PHPUnit\Framework\TestCase;
+
+class ActionImplementationTest extends TestCase {
+	private $class;
+	private $obj;
+
+	/**
+	 * @dataProvider dataActionsProvider
+	 */
+	public function testClassName($path) {
+		$this->setAction($path);
+		$this->assertTrue($this->class === ucfirst($this->class), 'class name must start with uppercase character');
+		$this->assertEquals(0, substr_count($this->class, ' '), 'class name must not contain spaces');
+		$this->assertStringEndsWith('Action', $this->class, 'class name must end with "Action"');
+	}
+
+	/**
+	 * @dataProvider dataActionsProvider
+	 */
+	public function testClassType($path) {
+		$this->setAction($path);
+		$this->assertInstanceOf(ActionInterface::class, $this->obj);
+	}
+
+	/**
+	 * @dataProvider dataActionsProvider
+	 */
+	public function testVisibleMethods($path) {
+		$allowedActionAbstract = get_class_methods(ActionAbstract::class);
+		sort($allowedActionAbstract);
+
+		$this->setAction($path);
+
+		$methods = get_class_methods($this->obj);
+		sort($methods);
+
+		$this->assertEquals($allowedActionAbstract, $methods);
+	}
+
+	public function dataActionsProvider() {
+		$actions = array();
+		foreach (glob(PATH_LIB_ACTIONS . '*.php') as $path) {
+			$actions[basename($path, '.php')] = array($path);
+		}
+		return $actions;
+	}
+
+	private function setAction($path) {
+		$this->class = '\\' . basename($path, '.php');
+		$this->assertTrue(class_exists($this->class), 'class ' . $this->class . ' doesn\'t exist');
+		$this->obj = new $this->class();
+	}
+}