Refactor tests and add TestSupport trait.

tests/AssetTest.php

@@ -9,13 +9,16 @@
     Asset\DateTimePickerAsset,
     Asset\DateTimePickerCdnAsset,
     Asset\JQueryProviderAsset,
-    DateTimePicker
+    DateTimePicker,
+    Tests\Support\TestSupport
 };
 use Yii;
 use yii\web\AssetBundle;
 
-final class AssetTest extends TestCase
+final class AssetTest extends \PHPUnit\Framework\TestCase
 {
+    use TestSupport;
+
     public function setup(): void
     {
         parent::setUp();

tests/DateTimePickerTest.php

@@ -5,11 +5,13 @@
 namespace Yii2\Extensions\DateTimePicker\Tests;
 
 use PHPForge\{Html\Textual\I, Support\Assert};
-use Yii2\Extensions\DateTimePicker\{DateTimePicker, Tests\Support\DateTimePickerModel};
+use Yii2\Extensions\DateTimePicker\{DateTimePicker, Tests\Support\DateTimePickerModel, Tests\Support\TestSupport};
 use Yii;
 
-final class DateTimePickerTest extends TestCase
+final class DateTimePickerTest extends \PHPUnit\Framework\TestCase
 {
+    use TestSupport;
+
     public function setup(): void
     {
         parent::setUp();

tests/ExceptionTest.php

@@ -7,7 +7,7 @@
 use Yii2\Extensions\DateTimePicker\DateTimePicker;
 use yii\base\InvalidConfigException;
 
-final class ExceptionTest extends TestCase
+final class ExceptionTest extends \PHPUnit\Framework\TestCase
 {
     public function testWithoutModelWithoutName(): void
     {

tests/Support/TestSupport.php

@@ -0,0 +1,71 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Yii2\Extensions\DateTimePicker\Tests\Support;
+
+use PHPForge\Support\Assert;
+use Yii;
+use yii\{di\Container, i18n\PhpMessageSource, web\Application, web\View};
+
+trait TestSupport
+{
+    protected View $view;
+
+    /**
+     * Clean up after test.
+     * By default the application created with [[mockApplication]] will be destroyed.
+     */
+    protected function tearDown(): void
+    {
+        parent::tearDown();
+        $this->destroyApplication();
+    }
+
+    protected function mockApplication(): void
+    {
+        new Application(
+            [
+                'id' => 'testapp',
+                'aliases' => [
+                    '@root' => dirname(__DIR__, 2),
+                    '@bower' => '@vendor/bower-asset',
+                    '@npm' => '@vendor/npm-asset',
+                ],
+                'basePath' => dirname(__DIR__, 2),
+                'components' => [
+                    'assetManager' => [
+                        'appendTimestamp' => false,
+                        'basePath' => __DIR__ . '/runtime',
+                        'baseUrl' => '/',
+                    ],
+                    'i18n' => [
+                        'translations' => [
+                            'yii2.extensions.datetime.picker' => [
+                                'class' => PhpMessageSource::class,
+                                'basePath' => dirname(__DIR__, 2) . '/resource/message',
+                            ],
+                        ],
+                    ],
+                    'request' => [
+                        'cookieValidationKey' => 'wefJDF8sfdsfSDefwqdxj9oq',
+                        'scriptFile' => __DIR__ . '/index.php',
+                        'scriptUrl' => '/index.php',
+                    ],
+                ],
+            ],
+        );
+    }
+
+    /**
+     * Destroys application in Yii::$app by setting it to null.
+     */
+    protected function destroyApplication()
+    {
+        Yii::$app = null;
+        Yii::$container = new Container();
+        Assert::removeFilesFromDirectory(__DIR__ . '/runtime');
+
+        unset($this->view);
+    }
+}