feat: rewrites --dirty support

src/TestCaseFilters/GitDirtyTestCaseFilter.php

@@ -0,0 +1,58 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Pest\TestCaseFilters;
+
+use Pest\Contracts\TestCaseFilter;
+use Pest\Exceptions\MissingDependency;
+use Symfony\Component\Process\Process;
+
+final class GitDirtyTestCaseFilter implements TestCaseFilter
+{
+    /**
+     * @var array<string>
+     */
+    private array $changedFiles = [];
+
+    public function __construct(private readonly string $projectRoot)
+    {
+        $this->loadDiff();
+    }
+
+    public function accept(string $testCaseFilename): bool
+    {
+        $relativePath = str_replace($this->projectRoot, '', $testCaseFilename);
+
+        if (str_starts_with($relativePath, '/')) {
+            $relativePath = substr($relativePath, 1);
+        }
+
+        return in_array($relativePath, $this->changedFiles, true);
+    }
+
+    private function loadDiff(): void
+    {
+        $process = new Process(['git', 'status', '--short', '--', '*.php']);
+        $process->run();
+
+        if (! $process->isSuccessful()) {
+            throw new MissingDependency('Filter by dirty files', 'git');
+        }
+
+        $output = preg_split('/\R+/', $process->getOutput(), flags: PREG_SPLIT_NO_EMPTY);
+        assert(is_array($output));
+
+        $dirtyFiles = [];
+
+        foreach ($output as $dirtyFile) {
+            $dirtyFiles[substr($dirtyFile, 3)] = trim(substr($dirtyFile, 0, 3));
+        }
+
+        $dirtyFiles = array_filter($dirtyFiles, fn ($status): bool => $status !== 'D');
+
+        $dirtyFiles = array_map(fn ($file, $status): string => in_array($status, ['R', 'RM'], true) ? explode(' -> ', $file)[1] : $file, array_keys($dirtyFiles), $dirtyFiles);
+
+        $this->changedFiles = $dirtyFiles = array_values($dirtyFiles);
+    }
+}