make file path symfony independent

app/FileSystem/StaticRelativeFilePathHelper.php

@@ -4,15 +4,12 @@
 
 namespace TomasVotruba\ClassLeak\FileSystem;
 
-use Symfony\Component\Filesystem\Filesystem;
-
 final class StaticRelativeFilePathHelper
 {
     public static function resolveFromCwd(string $filePath): string
     {
-        $filesystem = new Filesystem();
-        $relativeFilePathFromCwd = $filesystem->makePathRelative((string) realpath($filePath), getcwd());
-
-        return rtrim($relativeFilePathFromCwd, '/');
+        // make path relative with native PHP
+        $relativeFilePath = (string) realpath($filePath);
+        return str_replace(getcwd() . DIRECTORY_SEPARATOR, '', $relativeFilePath);
     }
 }

tests/FileSystem/Fixture/some-file.php

@@ -0,0 +1,5 @@
+<?php
+
+declare(strict_types=1);
+
+// some content

tests/FileSystem/StaticRelativeFilePathHelperTest.php

@@ -0,0 +1,17 @@
+<?php
+
+declare(strict_types=1);
+
+namespace TomasVotruba\ClassLeak\Tests\FileSystem;
+
+use PHPUnit\Framework\TestCase;
+use TomasVotruba\ClassLeak\FileSystem\StaticRelativeFilePathHelper;
+
+final class StaticRelativeFilePathHelperTest extends TestCase
+{
+    public function test(): void
+    {
+        $relativeFilePath = StaticRelativeFilePathHelper::resolveFromCwd(__DIR__ . '/Fixture/some-file.php');
+        $this->assertSame('tests/FileSystem/Fixture/some-file.php', $relativeFilePath);
+    }
+}