Refactor RemoveAnimationModifier::class, Add tests

tests/Unit/Modifiers/RemoveAnimationModifierTest.php

@@ -0,0 +1,44 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Intervention\Image\Tests\Unit\Modifiers;
+
+use Generator;
+use Intervention\Image\Interfaces\ImageInterface;
+use Intervention\Image\Modifiers\RemoveAnimationModifier;
+use Intervention\Image\Tests\BaseTestCase;
+use Mockery;
+use PHPUnit\Framework\Attributes\CoversClass;
+use PHPUnit\Framework\Attributes\DataProvider;
+
+#[CoversClass(RemoveAnimationModifier::class)]
+final class RemoveAnimationModifierTest extends BaseTestCase
+{
+    #[DataProvider('normalizePositionProvider')]
+    public function testNormalizePosition(int|string $position, int $frames, int $normalized): void
+    {
+        $modifier = new class ($position) extends RemoveAnimationModifier
+        {
+            public function testResult(int $frames): int
+            {
+                $image = Mockery::mock(ImageInterface::class)->makePartial();
+                $image->shouldReceive('count')->andReturn($frames);
+
+                return $this->normalizePosition($image);
+            }
+        };
+
+        $this->assertEquals($normalized, $modifier->testResult($frames));
+    }
+
+    public static function normalizePositionProvider(): Generator
+    {
+        yield [0, 100, 0];
+        yield [10, 100, 10];
+        yield ['10', 100, 10];
+        yield ['0%', 100, 0];
+        yield ['50%', 100, 50];
+        yield ['100%', 100, 99];
+    }
+}