Add phpunit configuration file

Use the configuration file to pass the location of the tests and
autoload class files.

Pass -sp to phpcs command

.github/workflows/php.yml

@@ -15,8 +15,8 @@ jobs:
       - name: Install dependencies
         run: composer install --prefer-dist --no-interaction --ansi
 
-      - name: Run tests
-        run: php${{ matrix.php }} ./vendor/bin/phpunit tests/php/*
-
       - name: Running phpcs
         run: composer run-script cs
+
+      - name: Run tests
+        run: php${{ matrix.php }} ./vendor/bin/phpunit

.gitignore

@@ -16,6 +16,7 @@ yarn-error.log*
 
 # PHP
 vendor/
+*.cache
 
 # Docs
 docs/_build/

composer.json

@@ -25,7 +25,6 @@
 			"email": "santhosh.thottingal@gmail.com"
 		}
 	],
-	"type": "library",
 	"require": {
 		"php": ">=7.2",
 		"mustangostang/spyc": "0.6.3"
@@ -45,11 +44,11 @@
 	},
 	"scripts": {
 		"fix": "phpcbf",
-		"cs": "phpcs -p",
+		"cs": "phpcs -sp",
 		"test": [
-			"composer validate --no-interaction",
+			"@composer validate --no-interaction",
-			"phpunit tests/php/*",
+			"phpunit",
-			"phpcs -p"
+			"@cs"
 		]
 	}
 }

phpunit.xml

@@ -0,0 +1,19 @@
+<?xml version="1.0" encoding="UTF-8"?>
+
+<phpunit
+		bootstrap="vendor/autoload.php"
+		beStrictAboutTestsThatDoNotTestAnything="true"
+		beStrictAboutOutputDuringTests="true">
+
+    <testsuites>
+        <testsuite name="Test suite">
+            <directory>tests/php</directory>
+        </testsuite>
+    </testsuites>
+
+    <filter>
+        <whitelist>
+            <directory suffix=".php">src/</directory>
+        </whitelist>
+    </filter>
+</phpunit>

src/LanguageUtil.php

@@ -38,7 +38,7 @@ class LanguageUtil {
 	/**
 	 * Returns an instance of the class that can be used to then call the other methods in the
 	 * class.
-	 * @return LanguageUtil
+	 * @return self
 	 */
 	public static function get(): LanguageUtil {
 		if ( self::$instance === null ) {

tests/php/LanguageUtilTest.php

@@ -1,6 +1,4 @@
 <?php
-require __DIR__ . '/../../src/LanguageUtil.php';
-
 use PHPUnit\Framework\TestCase;
 use Wikimedia\LanguageData\LanguageUtil;