fix: #140 Add PHPStan and update code to meet level 0

Adding one exception since it's not a quick-fix.

Author: star-szr

.gitignore

@@ -1,2 +1,3 @@
 /composer.lock
+/phpstan.neon
 /vendor

composer.json

@@ -37,9 +37,11 @@
         "composer/composer": "^2.9",
         "phpunit/phpunit": "^9.5",
         "symfony/process": "^6",
-        "dms/phpunit-arraysubset-asserts": "^0.5.0"
+        "dms/phpunit-arraysubset-asserts": "^0.5.0",
+        "phpstan/phpstan": "^2.1"
     },
     "scripts": {
+        "phpstan": "phpstan",
         "test": [
             "phpunit ./tests --debug"
         ]

phpstan-baseline.neon

@@ -0,0 +1,7 @@
+parameters:
+	ignoreErrors:
+		-
+			message: '#^Instantiated class Tuf\\Tests\\FixtureBuilder\\Fixture not found\.$#'
+			identifier: class.notFound
+			count: 1
+			path: tests/FunctionalTestBase.php

phpstan.neon.dist

@@ -0,0 +1,8 @@
+includes:
+  - phpstan-baseline.neon
+
+parameters:
+  level: 0
+  paths:
+    - src
+    - tests

src/ComposerFileStorage.php

@@ -14,7 +14,7 @@ class ComposerFileStorage extends FileStorage
     /**
      * {@inheritDoc}
      */
-    public function __construct(string $basePath)
+    final public function __construct(string $basePath)
     {
         (new Filesystem())->ensureDirectoryExists($basePath);
         parent::__construct($basePath);

tests/FunctionalTestBase.php

@@ -40,6 +40,8 @@ protected function setUp(): void
         mkdir($this->workingDir . '/tuf', recursive: true);
 
         // Make PHP-TUF's fixture builder available.
+        // @TODO: Consider moving the fixture builder to its own library that
+        // both php-tuf and composer-integration can pull in via require-dev.
         $loaders = ClassLoader::getRegisteredLoaders();
         reset($loaders)->addPsr4('Tuf\\Tests\\', key($loaders) . '/php-tuf/php-tuf/tests');