Add basic tests for ULS' ResourceLoader modules

This is a starting point to increase the test coverage in this code
base.

Change-Id: I215713e928e9b55615afd17ccf7a7082ef559e01

tests/phpunit/ResourceLoaderULSModuleTest.php

@@ -0,0 +1,29 @@
+<?php
+
+namespace UniversalLanguageSelector\Tests;
+
+use ResourceLoaderULSModule;
+
+/**
+ * @covers \ResourceLoaderULSModule
+ *
+ * @license GPL-2.0-or-later
+ * @author Thiemo Kreuz
+ */
+class ResourceLoaderULSModuleTest extends \PHPUnit\Framework\TestCase {
+	use \PHPUnit4And6Compat;
+
+	public function testAllReturnValues() {
+		$instance = new ResourceLoaderULSModule();
+
+		$context = $this->createMock( \ResourceLoaderContext::class );
+		$context->method( 'getLanguage' )
+			->willReturn( 'en' );
+
+		$script = $instance->getScript( $context );
+		$this->assertStringStartsWith( 'mw.config.set({"wgULSLanguages":{"', $script );
+
+		$this->assertTrue( $instance->enableModuleContentVersion() );
+	}
+
+}