Switch to relative paths

When this package was initially designed it didn't take into account situations where files aren't
moved. But are mounted into a running Docker container for development. By switching to relative
paths both situations, and most logical others are supported.

Resolves: WyriHaximus/reactphp-child-process-messenger#72 (reported by @lucasnetau)

composer.json

@@ -5,7 +5,8 @@
     "license": "MIT",
     "require": {
         "php": "^8 || ^7.4",
-        "composer-plugin-api": "^2"
+        "composer-plugin-api": "^2",
+        "wikimedia/relpath": "^2.1"
     },
     "require-dev": {
         "wyrihaximus/test-utilities": "^3"

src/BinAutoloadPathUpdater.php

@@ -12,6 +12,7 @@
 use Composer\Plugin\PluginInterface;
 use Composer\Script\Event;
 use Composer\Script\ScriptEvents;
+use Wikimedia\RelPath;
 
 use function array_key_exists;
 use function dirname;
@@ -72,7 +73,9 @@ private static function updatePackage(PackageInterface $package, string $vendorD
         }
 
         foreach ($package->getExtra()['wyrihaximus']['bin-autoload-path-update'] as $binPath) {
-            self::updateBinPath(self::getVendorPath($vendorDir, $package) . $binPath, $autoloaderPath);
+            $vendorPath             = self::getVendorPath($vendorDir, $package);
+            $relativeAutoloaderPath = (string) RelPath::getRelativePath($autoloaderPath, dirname($vendorPath . $binPath));
+            self::updateBinPath($vendorPath . $binPath, $relativeAutoloaderPath);
         }
     }
 

tests/BinAutoloadPathUpdaterTest.php

@@ -79,8 +79,8 @@ public function update(): void
 
         self::assertFileExists($tmpDir . 'bin/app-name');
         self::assertFileExists($tmpDir . 'vendor/wyrihaximus/b/bin/app-b-name');
-        self::assertSame($tmpDir . 'vendor/autoload.php', file_get_contents($tmpDir . 'bin/app-name'));
-        self::assertSame($tmpDir . 'vendor/autoload.php', file_get_contents($tmpDir . 'vendor/wyrihaximus/b/bin/app-b-name'));
+        self::assertSame('../vendor/autoload.php', file_get_contents($tmpDir . 'bin/app-name'));
+        self::assertSame('../../../autoload.php', file_get_contents($tmpDir . 'vendor/wyrihaximus/b/bin/app-b-name'));
     }
 
     /**