PHPUnit 10 Migration (#1302)

* Bump PHPUnit dependencies

* Set return type of base TestCase methods

From the [PHPUnit 8 release notes][1], the `TestCase` methods below now declare a `void` return type:

- `setUpBeforeClass()`
- `setUp()`
- `assertPreConditions()`
- `assertPostConditions()`
- `tearDown()`
- `tearDownAfterClass()`
- `onNotSuccessfulTest()`

[1]: https://phpunit.de/announcements/phpunit-8.html

* Ignore PHPUnit cache folder

* Adopt PHP attributes in test classes

* Declare data providers as `static`

* Add return types to test methods

* Define test classes as `final`

* Migrate phpunit.xml to phpunit 10

* Correct phpunit attribute class name

* Rename base test class

* Restructure test folders

* Fix test image paths

* Only set rules for php files in .editorconfig

* Remove php unit flag in local test env

---------

Co-authored-by: Shift <shift@laravelshift.com>

tests/BaseTestCase.php

@@ -0,0 +1,70 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Intervention\Image\Tests;
+
+use Intervention\Image\Colors\Rgb\Channels\Alpha;
+use Intervention\Image\Colors\Rgb\Color as RgbColor;
+use Intervention\Image\Interfaces\ColorInterface;
+use Mockery\Adapter\Phpunit\MockeryTestCase;
+
+abstract class BaseTestCase extends MockeryTestCase
+{
+    public function getTestImagePath($filename = 'test.jpg'): string
+    {
+        return sprintf('%s/images/%s', __DIR__, $filename);
+    }
+
+    public function getTestImageData($filename = 'test.jpg'): string
+    {
+        return file_get_contents($this->getTestImagePath($filename));
+    }
+
+    protected function assertColor($r, $g, $b, $a, ColorInterface $color)
+    {
+        $this->assertEquals([$r, $g, $b, $a], $color->toArray());
+    }
+
+    protected function assertTransparency(ColorInterface $color)
+    {
+        $this->assertInstanceOf(RgbColor::class, $color);
+        $channel = $color->channel(Alpha::class);
+        $this->assertEquals(0, $channel->value());
+    }
+
+    protected function assertMediaType(string|array $allowed, string $input): void
+    {
+        $pointer = fopen('php://temp', 'rw');
+        fputs($pointer, $input);
+        rewind($pointer);
+        $detected = mime_content_type($pointer);
+        fclose($pointer);
+
+        $allowed = is_string($allowed) ? [$allowed] : $allowed;
+        $this->assertTrue(in_array($detected, $allowed));
+    }
+
+    protected function assertMediaTypeBitmap(string $input): void
+    {
+        $this->assertMediaType([
+            'image/x-ms-bmp',
+            'image/bmp',
+            'bmp',
+            'ms-bmp',
+            'x-bitmap',
+            'x-bmp',
+            'x-ms-bmp',
+            'x-win-bitmap',
+            'x-windows-bmp',
+            'x-xbitmap',
+            'image/ms-bmp',
+            'image/x-bitmap',
+            'image/x-bmp',
+            'image/x-ms-bmp',
+            'image/x-win-bitmap',
+            'image/x-windows-bmp',
+            'image/x-xbitmap',
+        ], $input);
+    }
+}