From 3a1af9fac00b7dcbbde6e8983979fefeb0f812c1 Mon Sep 17 00:00:00 2001
From: Michiel Gerritsen <michiel@controlaltdelete.nl>
Date: Mon, 31 Aug 2026 18:20:12 +0200
Subject: [PATCH 1/2] Bugfix: Autoloaders require source, not the file

---
 .github/workflows/ci.yml                      |   5 +
 CHANGELOG.md                                  |  18 ++
 bin/ci_autoloader_smoke                       | 161 ++++++++++++++++++
 composer.json                                 |   1 +
 extension.neon                                |  19 +--
 phpstan.neon                                  |  30 ----
 ...acheStorage.php => GeneratedFileCache.php} |  53 +++---
 .../Magento/Autoload/ExtensionAutoloader.php  |  13 +-
 .../Autoload/ExtensionInterfaceAutoloader.php |  13 +-
 .../Magento/Autoload/FactoryAutoloader.php    |  13 +-
 .../Magento/Autoload/ProxyAutoloader.php      |  13 +-
 ...est.php => GeneratedFileCacheUnitTest.php} |  30 ++--
 .../Autoload/ExtensionAutoloaderUnitTest.php  |  31 ++--
 .../ExtensionInterfaceAutoloaderUnitTest.php  |  35 ++--
 .../Autoload/FactoryAutoloaderUnitTest.php    |  90 +++++++---
 .../Autoload/ProxyAutoloaderUnitTest.php      |  34 ++--
 .../Magento/Autoload/RegistrationUnitTest.php |   4 +-
 17 files changed, 378 insertions(+), 185 deletions(-)
 create mode 100755 bin/ci_autoloader_smoke
 rename src/bitExpert/PHPStan/Magento/Autoload/Cache/{FileCacheStorage.php => GeneratedFileCache.php} (62%)
 rename tests/bitExpert/PHPStan/Magento/Autoload/Cache/{FileCacheStorageUnitTest.php => GeneratedFileCacheUnitTest.php} (67%)

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 6f0a8b6..0300903 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -56,6 +56,11 @@ jobs:
       - name: Static code analysis
         run: composer analyze
 
+      - name: Autoloader smoke test
+        env:
+          REQUIRE_TURBO: '1'
+        run: composer smoke-test
+
       - name: Unittests
         if: matrix.coveralls == false
         run: composer test
diff --git a/CHANGELOG.md b/CHANGELOG.md
index fb2c37a..663cf7d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,24 @@
 
 All notable changes to this project will be documented in this file, in reverse chronological order by release.
 
+## Unreleased
+
+### Added
+
+- A CI smoke test (`composer smoke-test`) that runs a real analysis over a generated fixture project and fails when the generated-class autoloaders report an internal error.
+
+### Deprecated
+
+- Nothing.
+
+### Removed
+
+- `bitExpert\PHPStan\Magento\Autoload\Cache\FileCacheStorage`, replaced by `bitExpert\PHPStan\Magento\Autoload\Cache\GeneratedFileCache`. The autoloaders now take that class in place of `PHPStan\Cache\Cache`, and the generated classes move from `%tmpDir%/cache/PHPStan` to `%tmpDir%/cache/bitExpert/PHPStanMagento` so that they no longer share a directory with PHPStan's own cache.
+
+### Fixed
+
+- Fix "Internal error: Failed opening required '<?php ...'" for every generated Factory, Proxy, Extension and ExtensionInterface class on PHPStan 2.2.10 and PHP 8.3 or later. `FileCacheStorage` stored the generated source but returned a file path from `load()`, which a `PHPStan\Cache\CacheStorage` must not do. Once PHPStan served cache entries from its shared memory arena, `Cache::load()` returned the source code and the autoloaders required that in place of the file.
+
 ## 0.43.0
 
 ### Added
diff --git a/bin/ci_autoloader_smoke b/bin/ci_autoloader_smoke
new file mode 100755
index 0000000..d1d4c76
--- /dev/null
+++ b/bin/ci_autoloader_smoke
@@ -0,0 +1,161 @@
+#!/usr/bin/env php
+<?php
+
+/*
+ * This file is part of the phpstan-magento package.
+ *
+ * (c) bitExpert AG
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+declare(strict_types=1);
+
+/*
+ * Runs a real PHPStan analysis against a generated fixture project and fails when the autoloaders
+ * report an internal error.
+ *
+ * The fixture only asks for factories, which is enough: all four generated-class autoloaders
+ * share the store-then-require mechanism this guards.
+ *
+ * The autoloaders generate a class, store it and then require the stored file. Whenever PHPStan
+ * changes how it hands cached values back, that round trip can start to return the source code in
+ * place of the path, which turns every generated class into
+ * "Internal error: Failed opening required '<?php ...'". Unit tests cannot see this: it only shows
+ * with a cold cache, more than one analysis process, and PHPStan's turbo extension active.
+ *
+ * Set REQUIRE_TURBO=1 (the CI job does) to also fail when PHPStan's shared memory arena is not
+ * usable, so that the guard cannot pass without exercising the code path it protects.
+ */
+
+$repoRoot = dirname(__DIR__);
+$fixtureRoot = sys_get_temp_dir() . '/phpstan-magento-smoke-' . uniqid();
+$numberOfFiles = 100;
+
+function removeDirectory(string $directory): void
+{
+    if (!is_dir($directory)) {
+        return;
+    }
+
+    $entries = new RecursiveIteratorIterator(
+        new RecursiveDirectoryIterator($directory, FilesystemIterator::SKIP_DOTS),
+        RecursiveIteratorIterator::CHILD_FIRST
+    );
+
+    foreach ($entries as $entry) {
+        /** @var SplFileInfo $entry */
+        $entry->isDir() ? rmdir($entry->getPathname()) : unlink($entry->getPathname());
+    }
+
+    rmdir($directory);
+}
+
+function run(string $repoRoot, string $command, string $config): array
+{
+    $commandLine = sprintf(
+        '%s %s %s --configuration=%s 2>&1',
+        escapeshellarg(PHP_BINARY),
+        escapeshellarg($repoRoot . '/vendor/bin/phpstan'),
+        $command,
+        escapeshellarg($config)
+    );
+
+    $output = [];
+    $exitCode = 0;
+    exec($commandLine, $output, $exitCode);
+
+    return [implode(PHP_EOL, $output), $exitCode];
+}
+
+/*
+ * The arena is what makes the cache round trip observable, and the extension being loaded does not
+ * mean the arena works: on macOS the extension loads but never hands out an arena. Probe it the way
+ * PHPStan does, with the binary PHPStan itself reports.
+ */
+function arenaIsUsable(string $diagnoseOutput): bool
+{
+    if (preg_match('#^Turbo worker binary: (\S+)#m', $diagnoseOutput, $matches) !== 1) {
+        return false;
+    }
+
+    $probe = sprintf(
+        '%s -d %s -r %s 2>&1',
+        escapeshellarg(PHP_BINARY),
+        escapeshellarg('extension=' . $matches[1]),
+        escapeshellarg('echo \PHPStanTurbo\ArenaCache::create("probe") === null ? "no" : "yes";')
+    );
+
+    $output = [];
+    $exitCode = 0;
+    exec($probe, $output, $exitCode);
+
+    return $exitCode === 0 && in_array('yes', $output, true);
+}
+
+mkdir($fixtureRoot . '/src', 0777, true);
+
+for ($i = 1; $i <= $numberOfFiles; $i++) {
+    file_put_contents(
+        sprintf('%s/src/Consumer%d.php', $fixtureRoot, $i),
+        <<<PHP
+        <?php declare(strict_types=1);
+
+        namespace Smoke;
+
+        class Consumer{$i}
+        {
+            public function useFactory(\\Smoke\\Thing{$i}Factory \$factory): void
+            {
+                \$factory->create();
+            }
+        }
+
+        PHP
+    );
+}
+
+// A cold tmpDir matters: with a warm cache the autoloaders find the generated file before they
+// ever ask PHPStan to store anything, which hides the very problem this guard looks for.
+file_put_contents($fixtureRoot . '/phpstan.neon', <<<NEON
+includes:
+    - {$repoRoot}/extension.neon
+
+parameters:
+    tmpDir: {$fixtureRoot}/tmp
+    level: 2
+    paths:
+        - {$fixtureRoot}/src
+    magento:
+        magentoRoot: {$fixtureRoot}
+    parallel:
+        jobSize: 5
+        minimumNumberOfJobsPerProcess: 1
+        maximumNumberOfProcesses: 4
+
+NEON);
+
+[$diagnoseOutput] = run($repoRoot, 'diagnose', $fixtureRoot . '/phpstan.neon');
+$arenaIsUsable = strpos($diagnoseOutput, 'Turbo extension: enabled (') !== false
+    && arenaIsUsable($diagnoseOutput);
+
+echo 'PHPStan shared memory arena usable: ' . ($arenaIsUsable ? 'yes' : 'no') . PHP_EOL;
+
+if (!$arenaIsUsable && getenv('REQUIRE_TURBO') === '1') {
+    fwrite(STDERR, PHP_EOL . 'The shared memory arena is not usable, thus this guard would pass' . PHP_EOL);
+    fwrite(STDERR, 'without exercising the code path it protects. PHPStan reported:' . PHP_EOL . PHP_EOL);
+    fwrite(STDERR, $diagnoseOutput . PHP_EOL);
+    removeDirectory($fixtureRoot);
+    exit(1);
+}
+
+[$analyseOutput, $exitCode] = run($repoRoot, 'analyse --no-progress', $fixtureRoot . '/phpstan.neon');
+removeDirectory($fixtureRoot);
+
+if (strpos($analyseOutput, 'Internal error') !== false || $exitCode !== 0) {
+    fwrite(STDERR, PHP_EOL . 'The generated-class autoloaders did not survive a real analysis run:' . PHP_EOL . PHP_EOL);
+    fwrite(STDERR, $analyseOutput . PHP_EOL);
+    exit(1);
+}
+
+echo 'Autoloader smoke test passed.' . PHP_EOL;
diff --git a/composer.json b/composer.json
index 853b830..ef00731 100644
--- a/composer.json
+++ b/composer.json
@@ -63,6 +63,7 @@
     "cs-fix": "vendor/bin/phpcbf",
     "check-license": "vendor/bin/license-checker check",
     "analyze": "vendor/bin/phpstan analyze",
+    "smoke-test": "@php bin/ci_autoloader_smoke",
     "test": "vendor/bin/phpunit",
     "coverage": "vendor/bin/phpunit --coverage-clover clover.xml"
   },
diff --git a/extension.neon b/extension.neon
index a0cb5a5..0319010 100644
--- a/extension.neon
+++ b/extension.neon
@@ -61,16 +61,11 @@ services:
 		class: bitExpert\PHPStan\Magento\Rules\ResourceModelsShouldBeUsedDirectlyRule
 	-
 		class: bitExpert\PHPStan\Magento\Rules\SetTemplateDisallowedForBlockRule
-	fileCacheStorage:
-		class: bitExpert\PHPStan\Magento\Autoload\Cache\FileCacheStorage
+	generatedFileCache:
+		class: bitExpert\PHPStan\Magento\Autoload\Cache\GeneratedFileCache
 		arguments:
-			directory: %tmpDir%/cache/PHPStan
+			directory: %tmpDir%/cache/bitExpert/PHPStanMagento
 			magentoRoot: %magento.magentoRoot%
-	autoloaderCache:
-		autowired: false
-		class: PHPStan\Cache\Cache
-		arguments:
-			storage: @fileCacheStorage
 	extensionAttributeDataProvider:
 		class: bitExpert\PHPStan\Magento\Autoload\DataProvider\ExtensionAttributeDataProvider
 		arguments:
@@ -92,21 +87,21 @@ services:
 	factoryAutoloader:
 		class: bitExpert\PHPStan\Magento\Autoload\FactoryAutoloader
 		arguments:
-			cache: @autoloaderCache
+			cache: @generatedFileCache
 			classLoaderProvider: @classLoaderProvider
 		tags:
 			- phpstan.magento.autoloader
 	proxyAutoloader:
 		class: bitExpert\PHPStan\Magento\Autoload\ProxyAutoloader
 		arguments:
-			cache: @autoloaderCache
+			cache: @generatedFileCache
 			classLoaderProvider: @classLoaderProvider
 		tags:
 			- phpstan.magento.autoloader
 	extensionInterfaceAutoloader:
 		class: bitExpert\PHPStan\Magento\Autoload\ExtensionInterfaceAutoloader
 		arguments:
-			cache: @autoloaderCache
+			cache: @generatedFileCache
 			classLoaderProvider: @classLoaderProvider
 			attributeDataProvider: @extensionAttributeDataProvider
 		tags:
@@ -114,7 +109,7 @@ services:
 	extensionAutoloader:
 		class: bitExpert\PHPStan\Magento\Autoload\ExtensionAutoloader
 		arguments:
-			cache: @autoloaderCache
+			cache: @generatedFileCache
 			classLoaderProvider: @classLoaderProvider
 			attributeDataProvider: @extensionAttributeDataProvider
 		tags:
diff --git a/phpstan.neon b/phpstan.neon
index 62fcf75..2857700 100644
--- a/phpstan.neon
+++ b/phpstan.neon
@@ -7,21 +7,6 @@ parameters:
         - src/bitExpert
         - tests/bitExpert
     ignoreErrors:
-        -
-            message: '~is not covered by backward compatibility promise.~'
-            path: src/bitExpert/PHPStan/Magento/Autoload/Cache/FileCacheStorage.php
-        -
-            message: '~is not covered by backward compatibility promise.~'
-            path: src/bitExpert/PHPStan/Magento/Autoload/FactoryAutoloader.php
-        -
-            message: '~is not covered by backward compatibility promise.~'
-            path: src/bitExpert/PHPStan/Magento/Autoload/ProxyAutoloader.php
-        -
-            message: '~is not covered by backward compatibility promise.~'
-            path: src/bitExpert/PHPStan/Magento/Autoload/ExtensionAutoloader.php
-        -
-            message: '~is not covered by backward compatibility promise.~'
-            path: src/bitExpert/PHPStan/Magento/Autoload/ExtensionInterfaceAutoloader.php
         -
             message: '~is not covered by backward compatibility promise.~'
             path: src/bitExpert/PHPStan/Magento/Reflection/Framework/Session/SessionManagerMagicMethodReflectionExtension.php
@@ -37,24 +22,9 @@ parameters:
         -
             message: '~Function is_subclass_of\(\) is a runtime reflection concept that might not work in PHPStan~'
             path: 'src/bitExpert/PHPStan/Magento/Type/TestFrameworkObjectManagerDynamicReturnTypeExtension.php'
-        -
-            message: '~is not covered by backward compatibility promise.~'
-            path: tests/bitExpert/PHPStan/Magento/Autoload/FactoryAutoloaderUnitTest.php
-        -
-            message: '~is not covered by backward compatibility promise.~'
-            path: tests/bitExpert/PHPStan/Magento/Autoload/ProxyAutoloaderUnitTest.php
-        -
-            message: '~is not covered by backward compatibility promise.~'
-            path: tests/bitExpert/PHPStan/Magento/Autoload/RegistrationUnitTest.php
-        -
-            message: '~is not covered by backward compatibility promise.~'
-            path: tests/bitExpert/PHPStan/Magento/Autoload/ExtensionAutoloaderUnitTest.php
         -
             message: '~Parameter #1 \$argument of class ReflectionClass constructor expects class-string<MyUncachedExtension>|MyUncachedExtension, string given~'
             path: tests/bitExpert/PHPStan/Magento/Autoload/ExtensionAutoloaderUnitTest.php
-        -
-            message: '~is not covered by backward compatibility promise.~'
-            path: tests/bitExpert/PHPStan/Magento/Autoload/ExtensionInterfaceAutoloaderUnitTest.php
         -
             message: '~Parameter #1 \$argument of class ReflectionClass constructor expects class-string<UncachedExtensionInterface>|UncachedExtensionInterface, string given~'
             path: tests/bitExpert/PHPStan/Magento/Autoload/ExtensionInterfaceAutoloaderUnitTest.php
diff --git a/src/bitExpert/PHPStan/Magento/Autoload/Cache/FileCacheStorage.php b/src/bitExpert/PHPStan/Magento/Autoload/Cache/GeneratedFileCache.php
similarity index 62%
rename from src/bitExpert/PHPStan/Magento/Autoload/Cache/FileCacheStorage.php
rename to src/bitExpert/PHPStan/Magento/Autoload/Cache/GeneratedFileCache.php
index 4d59462..67416e1 100644
--- a/src/bitExpert/PHPStan/Magento/Autoload/Cache/FileCacheStorage.php
+++ b/src/bitExpert/PHPStan/Magento/Autoload/Cache/GeneratedFileCache.php
@@ -12,9 +12,15 @@
 
 namespace bitExpert\PHPStan\Magento\Autoload\Cache;
 
-use PHPStan\Cache\CacheStorage;
-
-class FileCacheStorage implements CacheStorage
+/**
+ * Stores the source code the autoloaders generate and hands back the path of the file holding it.
+ *
+ * This deliberately is not a PHPStan\Cache\CacheStorage: the autoloaders need the path of the
+ * generated file to require it, while a CacheStorage has to return what was handed to save().
+ * Mixing the two made the autoloaders require the source code itself once PHPStan started to
+ * serve cache entries from its shared memory arena.
+ */
+class GeneratedFileCache
 {
     /**
      * @var string
@@ -27,9 +33,10 @@ class FileCacheStorage implements CacheStorage
     private $magentoRoot;
 
     /**
-     * FileCacheStorage constructor.
+     * GeneratedFileCache constructor.
      *
      * @param string $directory
+     * @param string $magentoRoot
      */
     public function __construct(string $directory, string $magentoRoot)
     {
@@ -38,39 +45,41 @@ public function __construct(string $directory, string $magentoRoot)
     }
 
     /**
+     * Returns the path of the file generated for the given key, null when nothing was generated yet.
+     *
      * @param string $key
-     * @param string $variableKey
-     * @return mixed
+     * @return string|null
      */
-    public function load(string $key, string $variableKey)
+    public function getFile(string $key): ?string
     {
-        return (function (string $key): ?string {
-            $cacheDir = $this->getCacheDir($key);
-            $cacheFile = $this->getCacheFile($key);
-            if (!is_file($cacheDir . '/' . $cacheFile)) {
-                return null;
-            }
+        $cacheFile = $this->getCacheDir($key) . '/' . $this->getCacheFile($key);
+        if (!is_file($cacheFile)) {
+            return null;
+        }
 
-            return $cacheDir . '/' . $cacheFile;
-        })($key);
+        return $cacheFile;
     }
 
     /**
+     * Writes the given source code and returns the path of the file holding it.
+     *
      * @param string $key
-     * @param string $variableKey
-     * @param mixed $data
+     * @param string $contents
+     * @return string
      */
-    public function save(string $key, string $variableKey, $data): void
+    public function putFile(string $key, string $contents): string
     {
         $cacheDir = $this->getCacheDir($key);
-        $cacheFile = $this->getCacheFile($key);
+        $cacheFile = $cacheDir . '/' . $this->getCacheFile($key);
         $this->makeDir($cacheDir);
-        $tmpSuccess = @file_put_contents($cacheDir . '/' . $cacheFile, $data);
-        if ($tmpSuccess === false) {
+        $written = @file_put_contents($cacheFile, $contents);
+        if ($written === false) {
             throw new \InvalidArgumentException(
-                sprintf('Could not write data to cache file %s.', $cacheDir . '/' . $cacheFile)
+                sprintf('Could not write data to cache file %s.', $cacheFile)
             );
         }
+
+        return $cacheFile;
     }
 
     /**
diff --git a/src/bitExpert/PHPStan/Magento/Autoload/ExtensionAutoloader.php b/src/bitExpert/PHPStan/Magento/Autoload/ExtensionAutoloader.php
index b97845f..cb67ee2 100644
--- a/src/bitExpert/PHPStan/Magento/Autoload/ExtensionAutoloader.php
+++ b/src/bitExpert/PHPStan/Magento/Autoload/ExtensionAutoloader.php
@@ -12,6 +12,7 @@
 
 namespace bitExpert\PHPStan\Magento\Autoload;
 
+use bitExpert\PHPStan\Magento\Autoload\Cache\GeneratedFileCache;
 use bitExpert\PHPStan\Magento\Autoload\DataProvider\ClassLoaderProvider;
 use bitExpert\PHPStan\Magento\Autoload\DataProvider\ExtensionAttributeDataProvider;
 use Laminas\Code\Generator\ClassGenerator;
@@ -20,13 +21,12 @@
 use Laminas\Code\Generator\DocBlockGenerator;
 use Laminas\Code\Generator\MethodGenerator;
 use Laminas\Code\Generator\ParameterGenerator;
-use PHPStan\Cache\Cache;
 use ReflectionClass;
 
 class ExtensionAutoloader implements Autoloader
 {
     /**
-     * @var Cache
+     * @var GeneratedFileCache
      */
     private $cache;
     /**
@@ -41,12 +41,12 @@ class ExtensionAutoloader implements Autoloader
     /**
      * ExtensionAutoloader constructor.
      *
-     * @param Cache $cache
+     * @param GeneratedFileCache $cache
      * @param ClassLoaderProvider $classLoaderProvider
      * @param ExtensionAttributeDataProvider $attributeDataProvider
      */
     public function __construct(
-        Cache $cache,
+        GeneratedFileCache $cache,
         ClassLoaderProvider $classLoaderProvider,
         ExtensionAttributeDataProvider $attributeDataProvider
     ) {
@@ -65,10 +65,9 @@ public function autoload(string $class): void
         // local classes in your project. We need to check first if classes exists locally before generating them!
         $pathToLocalClass = $this->classLoaderProvider->findFile($class);
         if ($pathToLocalClass === false) {
-            $pathToLocalClass = $this->cache->load($class, '');
+            $pathToLocalClass = $this->cache->getFile($class);
             if ($pathToLocalClass === null) {
-                $this->cache->save($class, '', $this->getFileContents($class));
-                $pathToLocalClass = $this->cache->load($class, '');
+                $pathToLocalClass = $this->cache->putFile($class, $this->getFileContents($class));
             }
         }
 
diff --git a/src/bitExpert/PHPStan/Magento/Autoload/ExtensionInterfaceAutoloader.php b/src/bitExpert/PHPStan/Magento/Autoload/ExtensionInterfaceAutoloader.php
index e619323..15f8e12 100644
--- a/src/bitExpert/PHPStan/Magento/Autoload/ExtensionInterfaceAutoloader.php
+++ b/src/bitExpert/PHPStan/Magento/Autoload/ExtensionInterfaceAutoloader.php
@@ -12,6 +12,7 @@
 
 namespace bitExpert\PHPStan\Magento\Autoload;
 
+use bitExpert\PHPStan\Magento\Autoload\Cache\GeneratedFileCache;
 use bitExpert\PHPStan\Magento\Autoload\DataProvider\ClassLoaderProvider;
 use bitExpert\PHPStan\Magento\Autoload\DataProvider\ExtensionAttributeDataProvider;
 use Laminas\Code\Generator\DocBlock\Tag\ParamTag;
@@ -20,12 +21,11 @@
 use Laminas\Code\Generator\InterfaceGenerator;
 use Laminas\Code\Generator\MethodGenerator;
 use Laminas\Code\Generator\ParameterGenerator;
-use PHPStan\Cache\Cache;
 
 class ExtensionInterfaceAutoloader implements Autoloader
 {
     /**
-     * @var Cache
+     * @var GeneratedFileCache
      */
     private $cache;
     /**
@@ -40,12 +40,12 @@ class ExtensionInterfaceAutoloader implements Autoloader
     /**
      * ExtensionInterfaceAutoloader constructor.
      *
-     * @param Cache $cache
+     * @param GeneratedFileCache $cache
      * @param ExtensionAttributeDataProvider $attributeDataProvider
      * @param ClassLoaderProvider $classLoaderProvider
      */
     public function __construct(
-        Cache $cache,
+        GeneratedFileCache $cache,
         ClassLoaderProvider $classLoaderProvider,
         ExtensionAttributeDataProvider $attributeDataProvider
     ) {
@@ -64,10 +64,9 @@ public function autoload(string $interfaceName): void
         // local classes in your project. We need to check first if classes exists locally before generating them!
         $pathToLocalInterface = $this->classLoaderProvider->findFile($interfaceName);
         if ($pathToLocalInterface === false) {
-            $pathToLocalInterface = $this->cache->load($interfaceName, '');
+            $pathToLocalInterface = $this->cache->getFile($interfaceName);
             if ($pathToLocalInterface === null) {
-                $this->cache->save($interfaceName, '', $this->getFileContents($interfaceName));
-                $pathToLocalInterface = $this->cache->load($interfaceName, '');
+                $pathToLocalInterface = $this->cache->putFile($interfaceName, $this->getFileContents($interfaceName));
             }
         }
 
diff --git a/src/bitExpert/PHPStan/Magento/Autoload/FactoryAutoloader.php b/src/bitExpert/PHPStan/Magento/Autoload/FactoryAutoloader.php
index 51630c2..1875aec 100644
--- a/src/bitExpert/PHPStan/Magento/Autoload/FactoryAutoloader.php
+++ b/src/bitExpert/PHPStan/Magento/Autoload/FactoryAutoloader.php
@@ -12,13 +12,13 @@
 
 namespace bitExpert\PHPStan\Magento\Autoload;
 
+use bitExpert\PHPStan\Magento\Autoload\Cache\GeneratedFileCache;
 use bitExpert\PHPStan\Magento\Autoload\DataProvider\ClassLoaderProvider;
-use PHPStan\Cache\Cache;
 
 class FactoryAutoloader implements Autoloader
 {
     /**
-     * @var Cache
+     * @var GeneratedFileCache
      */
     private $cache;
     /**
@@ -29,10 +29,10 @@ class FactoryAutoloader implements Autoloader
     /**
      * FactoryAutoloader constructor.
      *
-     * @param Cache $cache
+     * @param GeneratedFileCache $cache
      * @param ClassLoaderProvider $classLoaderProvider
      */
-    public function __construct(Cache $cache, ClassLoaderProvider $classLoaderProvider)
+    public function __construct(GeneratedFileCache $cache, ClassLoaderProvider $classLoaderProvider)
     {
         $this->cache = $cache;
         $this->classLoaderProvider = $classLoaderProvider;
@@ -48,10 +48,9 @@ public function autoload(string $class): void
         // local classes in your project. We need to check first if classes exists locally before generating them!
         $pathToLocalClass = $this->classLoaderProvider->findFile($class);
         if ($pathToLocalClass === false) {
-            $pathToLocalClass = $this->cache->load($class, '');
+            $pathToLocalClass = $this->cache->getFile($class);
             if ($pathToLocalClass === null) {
-                $this->cache->save($class, '', $this->getFileContents($class));
-                $pathToLocalClass = $this->cache->load($class, '');
+                $pathToLocalClass = $this->cache->putFile($class, $this->getFileContents($class));
             }
         }
 
diff --git a/src/bitExpert/PHPStan/Magento/Autoload/ProxyAutoloader.php b/src/bitExpert/PHPStan/Magento/Autoload/ProxyAutoloader.php
index c4f0131..f52165c 100644
--- a/src/bitExpert/PHPStan/Magento/Autoload/ProxyAutoloader.php
+++ b/src/bitExpert/PHPStan/Magento/Autoload/ProxyAutoloader.php
@@ -12,13 +12,13 @@
 
 namespace bitExpert\PHPStan\Magento\Autoload;
 
+use bitExpert\PHPStan\Magento\Autoload\Cache\GeneratedFileCache;
 use bitExpert\PHPStan\Magento\Autoload\DataProvider\ClassLoaderProvider;
-use PHPStan\Cache\Cache;
 
 class ProxyAutoloader implements Autoloader
 {
     /**
-     * @var Cache
+     * @var GeneratedFileCache
      */
     private $cache;
     /**
@@ -29,10 +29,10 @@ class ProxyAutoloader implements Autoloader
     /**
      * ProxyAutoloader constructor.
      *
-     * @param Cache $cache
+     * @param GeneratedFileCache $cache
      * @param ClassLoaderProvider $classLoaderProvider
      */
-    public function __construct(Cache $cache, ClassLoaderProvider $classLoaderProvider)
+    public function __construct(GeneratedFileCache $cache, ClassLoaderProvider $classLoaderProvider)
     {
         $this->cache = $cache;
         $this->classLoaderProvider = $classLoaderProvider;
@@ -48,10 +48,9 @@ public function autoload(string $class): void
         // local classes in your project. We need to check first if classes exists locally before generating them!
         $pathToLocalClass = $this->classLoaderProvider->findFile($class);
         if ($pathToLocalClass === false) {
-            $pathToLocalClass = $this->cache->load($class, '');
+            $pathToLocalClass = $this->cache->getFile($class);
             if ($pathToLocalClass === null) {
-                $this->cache->save($class, '', $this->getFileContents($class));
-                $pathToLocalClass = $this->cache->load($class, '');
+                $pathToLocalClass = $this->cache->putFile($class, $this->getFileContents($class));
             }
         }
 
diff --git a/tests/bitExpert/PHPStan/Magento/Autoload/Cache/FileCacheStorageUnitTest.php b/tests/bitExpert/PHPStan/Magento/Autoload/Cache/GeneratedFileCacheUnitTest.php
similarity index 67%
rename from tests/bitExpert/PHPStan/Magento/Autoload/Cache/FileCacheStorageUnitTest.php
rename to tests/bitExpert/PHPStan/Magento/Autoload/Cache/GeneratedFileCacheUnitTest.php
index f1bd852..958b5b4 100644
--- a/tests/bitExpert/PHPStan/Magento/Autoload/Cache/FileCacheStorageUnitTest.php
+++ b/tests/bitExpert/PHPStan/Magento/Autoload/Cache/GeneratedFileCacheUnitTest.php
@@ -17,21 +17,21 @@
 use org\bovigo\vfs\vfsStreamDirectory;
 use PHPUnit\Framework\TestCase;
 
-class FileCacheStorageUnitTest extends TestCase
+class GeneratedFileCacheUnitTest extends TestCase
 {
     /**
      * @var vfsStreamDirectory
      */
     private $root;
     /**
-     * @var FileCacheStorage
+     * @var GeneratedFileCache
      */
-    private $storage;
+    private $cache;
 
     public function setUp(): void
     {
         $this->root = vfsStream::setup('tmp');
-        $this->storage = new FileCacheStorage($this->root->url(), 'mage249');
+        $this->cache = new GeneratedFileCache($this->root->url(), 'mage249');
     }
 
     /**
@@ -39,7 +39,7 @@ public function setUp(): void
      */
     public function nullReturnedWhenLookingUpNonExistentFileInCache(): void
     {
-        $absFilename = $this->storage->load('test.txt', '');
+        $absFilename = $this->cache->getFile('test.txt');
 
         self::assertNull($absFilename);
     }
@@ -54,7 +54,7 @@ public function absoluteFilenameReturnedWhenLookingUpExistentFileInCache(): void
             $this->root
         );
 
-        $absFilename = $this->storage->load('test.txt', '');
+        $absFilename = $this->cache->getFile('test.txt');
 
         self::assertSame($absFilename, vfsStream::url('tmp/03/ef/4b6fcb2d521ef0fd442a5301e7932d16cc9f375a.php'));
     }
@@ -64,10 +64,21 @@ public function absoluteFilenameReturnedWhenLookingUpExistentFileInCache(): void
      */
     public function addingFileToCacheSucceeds(): void
     {
-        $this->storage->save('test.txt', '', 'Lorem ipsum');
-        $absFilename = $this->storage->load('test.txt', '');
+        $writtenFilename = $this->cache->putFile('test.txt', 'Lorem ipsum');
+        $absFilename = $this->cache->getFile('test.txt');
 
         self::assertSame($absFilename, vfsStream::url('tmp/03/ef/4b6fcb2d521ef0fd442a5301e7932d16cc9f375a.php'));
+        self::assertSame($absFilename, $writtenFilename);
+    }
+
+    /**
+     * @test
+     */
+    public function contentsAreWrittenToTheReturnedFile(): void
+    {
+        $writtenFilename = $this->cache->putFile('test.txt', 'Lorem ipsum');
+
+        self::assertSame('Lorem ipsum', file_get_contents($writtenFilename));
     }
 
     /**
@@ -80,7 +91,6 @@ public function addingFileToCacheFails(): void
         // simulate full disk
         vfsStream::setQuota(1);
 
-        $this->storage->save('test.txt', '', 'Lorem ipsum');
-        $this->storage->load('test.txt', '');
+        $this->cache->putFile('test.txt', 'Lorem ipsum');
     }
 }
diff --git a/tests/bitExpert/PHPStan/Magento/Autoload/ExtensionAutoloaderUnitTest.php b/tests/bitExpert/PHPStan/Magento/Autoload/ExtensionAutoloaderUnitTest.php
index 6fdebd6..7dc0b39 100644
--- a/tests/bitExpert/PHPStan/Magento/Autoload/ExtensionAutoloaderUnitTest.php
+++ b/tests/bitExpert/PHPStan/Magento/Autoload/ExtensionAutoloaderUnitTest.php
@@ -2,24 +2,18 @@
 
 namespace bitExpert\PHPStan\Magento\Autoload;
 
-use bitExpert\PHPStan\Magento\Autoload\Cache\FileCacheStorage;
+use bitExpert\PHPStan\Magento\Autoload\Cache\GeneratedFileCache;
 use bitExpert\PHPStan\Magento\Autoload\DataProvider\ClassLoaderProvider;
 use bitExpert\PHPStan\Magento\Autoload\DataProvider\ExtensionAttributeDataProvider;
 use org\bovigo\vfs\vfsStream;
-use PHPStan\Cache\Cache;
-use PHPStan\Cache\CacheStorage;
 use PHPUnit\Framework\TestCase;
 
 class ExtensionAutoloaderUnitTest extends TestCase
 {
     /**
-     * @var Cache
+     * @var GeneratedFileCache&\PHPUnit\Framework\MockObject\MockObject
      */
     private $cache;
-    /**
-     * @var CacheStorage&\PHPUnit\Framework\MockObject\MockObject
-     */
-    private $cacheStorage;
     /**
      * @var ClassLoaderProvider&\PHPUnit\Framework\MockObject\MockObject
      */
@@ -35,8 +29,7 @@ class ExtensionAutoloaderUnitTest extends TestCase
 
     protected function setUp(): void
     {
-        $this->cacheStorage = $this->createMock(CacheStorage::class);
-        $this->cache = new Cache($this->cacheStorage);
+        $this->cache = $this->createMock(GeneratedFileCache::class);
         $this->classLoader = $this->createMock(ClassLoaderProvider::class);
         $this->extAttrDataProvider = $this->createMock(ExtensionAttributeDataProvider::class);
         $this->autoloader = new ExtensionAutoloader(
@@ -53,8 +46,8 @@ public function autoloaderIgnoresClassesWithoutExtensionInterfacePostfix(): void
     {
         $this->classLoader->expects(self::never())
             ->method('findFile');
-        $this->cacheStorage->expects(self::never())
-            ->method('load');
+        $this->cache->expects(self::never())
+            ->method('getFile');
 
         $this->autoloader->autoload('SomeClass');
     }
@@ -67,8 +60,8 @@ public function autoloaderPrefersLocalFile(): void
         $this->classLoader->expects(self::once())
             ->method('findFile')
             ->willReturn(__DIR__ . '/HelperExtension.php');
-        $this->cacheStorage->expects(self::never())
-            ->method('load');
+        $this->cache->expects(self::never())
+            ->method('getFile');
 
         $this->autoloader->autoload(HelperExtension::class);
 
@@ -83,12 +76,12 @@ public function autoloaderUsesCachedFileWhenFound(): void
         $this->classLoader->expects(self::once())
             ->method('findFile')
             ->willReturn(false);
-        $this->cacheStorage->expects(self::once())
-            ->method('load')
+        $this->cache->expects(self::once())
+            ->method('getFile')
             ->willReturn(__DIR__ . '/HelperExtension.php');
 
-        $this->cacheStorage->expects(self::never())
-            ->method('save');
+        $this->cache->expects(self::never())
+            ->method('putFile');
 
         $this->autoloader->autoload(HelperExtension::class);
 
@@ -113,7 +106,7 @@ public function autoloadGeneratesInterfaceWhenNotCached(): void
         class_alias(HelperExtensionInterface::class, 'MyUncachedExtensionInterface');
 
         $root = vfsStream::setup('test');
-        $cache = new Cache(new FileCacheStorage($root->url() . '/tmp/cache/PHPStan', 'mage249'));
+        $cache = new GeneratedFileCache($root->url() . '/tmp/cache/bitExpert/PHPStanMagento', 'mage249');
         $autoloader = new ExtensionAutoloader($cache, $this->classLoader, $this->extAttrDataProvider);
 
         $autoloader->autoload($className);
diff --git a/tests/bitExpert/PHPStan/Magento/Autoload/ExtensionInterfaceAutoloaderUnitTest.php b/tests/bitExpert/PHPStan/Magento/Autoload/ExtensionInterfaceAutoloaderUnitTest.php
index 4386ef1..6c2740b 100644
--- a/tests/bitExpert/PHPStan/Magento/Autoload/ExtensionInterfaceAutoloaderUnitTest.php
+++ b/tests/bitExpert/PHPStan/Magento/Autoload/ExtensionInterfaceAutoloaderUnitTest.php
@@ -2,25 +2,19 @@
 
 namespace bitExpert\PHPStan\Magento\Autoload;
 
-use bitExpert\PHPStan\Magento\Autoload\Cache\FileCacheStorage;
+use bitExpert\PHPStan\Magento\Autoload\Cache\GeneratedFileCache;
 use bitExpert\PHPStan\Magento\Autoload\DataProvider\ClassLoaderProvider;
 use bitExpert\PHPStan\Magento\Autoload\DataProvider\ExtensionAttributeDataProvider;
 use InvalidArgumentException;
 use org\bovigo\vfs\vfsStream;
-use PHPStan\Cache\Cache;
-use PHPStan\Cache\CacheStorage;
 use PHPUnit\Framework\TestCase;
 
 class ExtensionInterfaceAutoloaderUnitTest extends TestCase
 {
     /**
-     * @var Cache
+     * @var GeneratedFileCache&\PHPUnit\Framework\MockObject\MockObject
      */
     private $cache;
-    /**
-     * @var CacheStorage&\PHPUnit\Framework\MockObject\MockObject
-     */
-    private $cacheStorage;
     /**
      * @var ExtensionAttributeDataProvider&\PHPUnit\Framework\MockObject\MockObject
      */
@@ -36,8 +30,7 @@ class ExtensionInterfaceAutoloaderUnitTest extends TestCase
 
     protected function setUp(): void
     {
-        $this->cacheStorage = $this->createMock(CacheStorage::class);
-        $this->cache = new Cache($this->cacheStorage);
+        $this->cache = $this->createMock(GeneratedFileCache::class);
         $this->classLoader = $this->createMock(ClassLoaderProvider::class);
         $this->extAttrDataProvider = $this->createMock(ExtensionAttributeDataProvider::class);
         $this->autoloader = new ExtensionInterfaceAutoloader(
@@ -54,8 +47,8 @@ public function autoloaderIgnoresClassesWithoutExtensionInterfacePostfix(): void
     {
         $this->classLoader->expects(self::never())
             ->method('findFile');
-        $this->cacheStorage->expects(self::never())
-            ->method('load');
+        $this->cache->expects(self::never())
+            ->method('getFile');
 
         $this->autoloader->autoload('SomeClass');
     }
@@ -68,8 +61,8 @@ public function autoloaderPrefersLocalFile(): void
         $this->classLoader->expects(self::once())
             ->method('findFile')
             ->willReturn(__DIR__ . '/HelperExtensionInterface.php');
-        $this->cacheStorage->expects(self::never())
-            ->method('load');
+        $this->cache->expects(self::never())
+            ->method('getFile');
 
         $this->autoloader->autoload(HelperExtensionInterface::class);
 
@@ -84,12 +77,12 @@ public function autoloaderUsesCachedFileWhenFound(): void
         $this->classLoader->expects(self::once())
             ->method('findFile')
             ->willReturn(false);
-        $this->cacheStorage->expects(self::once())
-            ->method('load')
+        $this->cache->expects(self::once())
+            ->method('getFile')
             ->willReturn(__DIR__ . '/HelperExtensionInterface.php');
 
-        $this->cacheStorage->expects(self::never())
-            ->method('save');
+        $this->cache->expects(self::never())
+            ->method('putFile');
 
         $this->autoloader->autoload(HelperExtensionInterface::class);
 
@@ -109,8 +102,8 @@ public function autoloadDoesNotGenerateInterfaceWhenNoAttributesExist(): void
         $this->classLoader->expects(self::once())
             ->method('findFile')
             ->willReturn(false);
-        $this->cacheStorage->expects(self::once())
-            ->method('load')
+        $this->cache->expects(self::once())
+            ->method('getFile')
             ->willReturn(null);
 
         $this->classLoader->expects(self::once())
@@ -128,7 +121,7 @@ public function autoloadGeneratesInterfaceWhenNotCached(): void
         $interfaceName = 'UncachedExtensionInterface';
 
         $root = vfsStream::setup('test');
-        $cache = new Cache(new FileCacheStorage($root->url() . '/tmp/cache/PHPStan', 'mage249'));
+        $cache = new GeneratedFileCache($root->url() . '/tmp/cache/bitExpert/PHPStanMagento', 'mage249');
         $autoloader = new ExtensionInterfaceAutoloader($cache, $this->classLoader, $this->extAttrDataProvider);
 
         $this->classLoader->expects(self::once())
diff --git a/tests/bitExpert/PHPStan/Magento/Autoload/FactoryAutoloaderUnitTest.php b/tests/bitExpert/PHPStan/Magento/Autoload/FactoryAutoloaderUnitTest.php
index 677bce6..8af8abf 100644
--- a/tests/bitExpert/PHPStan/Magento/Autoload/FactoryAutoloaderUnitTest.php
+++ b/tests/bitExpert/PHPStan/Magento/Autoload/FactoryAutoloaderUnitTest.php
@@ -12,17 +12,16 @@
 
 namespace bitExpert\PHPStan\Magento\Autoload;
 
+use bitExpert\PHPStan\Magento\Autoload\Cache\GeneratedFileCache;
 use bitExpert\PHPStan\Magento\Autoload\DataProvider\ClassLoaderProvider;
-use PHPStan\Cache\Cache;
-use PHPStan\Cache\CacheStorage;
 use PHPUnit\Framework\TestCase;
 
 class FactoryAutoloaderUnitTest extends TestCase
 {
     /**
-     * @var CacheStorage|\PHPUnit\Framework\MockObject\MockObject
+     * @var GeneratedFileCache|\PHPUnit\Framework\MockObject\MockObject
      */
-    private $storage;
+    private $cache;
     /**
      * @var FactoryAutoloader
      */
@@ -31,13 +30,26 @@ class FactoryAutoloaderUnitTest extends TestCase
      * @var ClassLoaderProvider|\PHPUnit\Framework\MockObject\MockObject
      */
     private $classLoader;
+    /**
+     * @var string[]
+     */
+    private $tempFiles = [];
 
     public function setUp(): void
     {
-        $this->storage = $this->createMock(CacheStorage::class);
+        $this->cache = $this->createMock(GeneratedFileCache::class);
         $this->classLoader = $this->createMock(ClassLoaderProvider::class);
 
-        $this->autoloader = new FactoryAutoloader(new Cache($this->storage), $this->classLoader);
+        $this->autoloader = new FactoryAutoloader($this->cache, $this->classLoader);
+    }
+
+    public function tearDown(): void
+    {
+        foreach ($this->tempFiles as $tempFile) {
+            @unlink($tempFile);
+        }
+
+        $this->tempFiles = [];
     }
 
     /**
@@ -47,8 +59,8 @@ public function autoloaderIgnoresClassesWithoutFactoryPostfix(): void
     {
         $this->classLoader->expects(self::never())
             ->method('findFile');
-        $this->storage->expects(self::never())
-            ->method('load');
+        $this->cache->expects(self::never())
+            ->method('getFile');
 
         $this->autoloader->autoload('SomeClass');
     }
@@ -61,8 +73,8 @@ public function autoloaderPrefersLocalFile(): void
         $this->classLoader->expects(self::once())
             ->method('findFile')
             ->willReturn(__DIR__ . '/HelperFactory.php');
-        $this->storage->expects(self::never())
-            ->method('load');
+        $this->cache->expects(self::never())
+            ->method('getFile');
 
         $this->autoloader->autoload(HelperFactory::class);
 
@@ -77,9 +89,11 @@ public function autoloaderUsesCachedFileWhenFound(): void
         $this->classLoader->expects(self::once())
             ->method('findFile')
             ->willReturn(false);
-        $this->storage->expects(self::once())
-            ->method('load')
+        $this->cache->expects(self::once())
+            ->method('getFile')
             ->willReturn(__DIR__ . '/HelperFactory.php');
+        $this->cache->expects(self::never())
+            ->method('putFile');
 
         $this->autoloader->autoload(HelperFactory::class);
 
@@ -94,17 +108,46 @@ public function autoloaderGeneratesCacheFileWhenNotFoundInCache(): void
         $this->classLoader->expects(self::once())
             ->method('findFile')
             ->willReturn(false);
-        $this->storage->expects(self::atMost(2))
-            ->method('load')
-            ->willReturnOnConsecutiveCalls(null, __DIR__ . '/HelperFactory.php');
-        $this->storage->expects(self::once())
-            ->method('save');
+        $this->cache->expects(self::once())
+            ->method('getFile')
+            ->willReturn(null);
+        $this->cache->expects(self::once())
+            ->method('putFile')
+            ->willReturn(__DIR__ . '/HelperFactory.php');
 
         $this->autoloader->autoload(HelperFactory::class);
 
         self::assertTrue(class_exists(HelperFactory::class, false));
     }
 
+    /**
+     * @test
+     */
+    public function autoloaderRequiresTheGeneratedFileAndNotTheGeneratedSource(): void
+    {
+        $className = 'bitExpert\PHPStan\Magento\Autoload\PathNotSourceThingFactory';
+
+        $this->classLoader->expects(self::once())
+            ->method('findFile')
+            ->willReturn(false);
+        $this->cache->expects(self::once())
+            ->method('getFile')
+            ->willReturn(null);
+        $this->cache->expects(self::once())
+            ->method('putFile')
+            ->willReturnCallback(function (string $key, string $contents): string {
+                $file = sys_get_temp_dir() . '/phpstan-magento-' . uniqid() . '.php';
+                file_put_contents($file, $contents);
+                $this->tempFiles[] = $file;
+
+                return $file;
+            });
+
+        $this->autoloader->autoload($className);
+
+        self::assertTrue(class_exists($className, false));
+    }
+
     /**
      * @test
      */
@@ -113,14 +156,13 @@ public function autoloaderGeneratesFactoryForCorrectClassname(): void
         $this->classLoader->expects(self::once())
             ->method('findFile')
             ->willReturn(false);
-        $this->storage->expects(self::atMost(2))
-            ->method('load')
-            ->willReturnOnConsecutiveCalls(null, __DIR__ . '/FactoryThingFactory.php');
-        $this->storage->expects(self::once())
-            ->method('save')
+        $this->cache->expects(self::once())
+            ->method('getFile')
+            ->willReturn(null);
+        $this->cache->expects(self::once())
+            ->method('putFile')
             ->with(
                 'bitExpert\PHPStan\Magento\Autoload\FactoryThingFactory',
-                static::isType('string'),
                 static::stringContains(<<<DOC
 /**
  * Factory class for @see \bitExpert\PHPStan\Magento\Autoload\FactoryThing
@@ -128,7 +170,7 @@ public function autoloaderGeneratesFactoryForCorrectClassname(): void
 DOC
                 )
             )
-        ;
+            ->willReturn(__DIR__ . '/FactoryThingFactory.php');
 
         $this->autoloader->autoload(FactoryThingFactory::class);
     }
diff --git a/tests/bitExpert/PHPStan/Magento/Autoload/ProxyAutoloaderUnitTest.php b/tests/bitExpert/PHPStan/Magento/Autoload/ProxyAutoloaderUnitTest.php
index e2815f8..1aea8d7 100644
--- a/tests/bitExpert/PHPStan/Magento/Autoload/ProxyAutoloaderUnitTest.php
+++ b/tests/bitExpert/PHPStan/Magento/Autoload/ProxyAutoloaderUnitTest.php
@@ -12,17 +12,16 @@
 
 namespace bitExpert\PHPStan\Magento\Autoload;
 
+use bitExpert\PHPStan\Magento\Autoload\Cache\GeneratedFileCache;
 use bitExpert\PHPStan\Magento\Autoload\DataProvider\ClassLoaderProvider;
-use PHPStan\Cache\Cache;
-use PHPStan\Cache\CacheStorage;
 use PHPUnit\Framework\TestCase;
 
 class ProxyAutoloaderUnitTest extends TestCase
 {
     /**
-     * @var CacheStorage|\PHPUnit\Framework\MockObject\MockObject
+     * @var GeneratedFileCache|\PHPUnit\Framework\MockObject\MockObject
      */
-    private $storage;
+    private $cache;
     /**
      * @var ProxyAutoloader
      */
@@ -34,10 +33,10 @@ class ProxyAutoloaderUnitTest extends TestCase
 
     public function setUp(): void
     {
-        $this->storage = $this->createMock(CacheStorage::class);
+        $this->cache = $this->createMock(GeneratedFileCache::class);
         $this->classLoader = $this->createMock(ClassLoaderProvider::class);
 
-        $this->autoloader = new ProxyAutoloader(new Cache($this->storage), $this->classLoader);
+        $this->autoloader = new ProxyAutoloader($this->cache, $this->classLoader);
     }
 
     /**
@@ -47,8 +46,8 @@ public function autoloaderIgnoresClassesWithoutProxyPostfix(): void
     {
         $this->classLoader->expects(self::never())
             ->method('findFile');
-        $this->storage->expects(self::never())
-            ->method('load');
+        $this->cache->expects(self::never())
+            ->method('getFile');
 
         $this->autoloader->autoload('SomeClass');
     }
@@ -61,8 +60,8 @@ public function autoloaderPrefersLocalFile(): void
         $this->classLoader->expects(self::once())
             ->method('findFile')
             ->willReturn(__DIR__ . '/HelperProxy.php');
-        $this->storage->expects(self::never())
-            ->method('load');
+        $this->cache->expects(self::never())
+            ->method('getFile');
 
         $this->autoloader->autoload('\bitExpert\PHPStan\Magento\Autoload\Helper\Proxy');
 
@@ -77,8 +76,8 @@ public function autoloaderUsesCachedFileWhenFound(): void
         $this->classLoader->expects(self::once())
             ->method('findFile')
             ->willReturn(false);
-        $this->storage->expects(self::once())
-            ->method('load')
+        $this->cache->expects(self::once())
+            ->method('getFile')
             ->willReturn(__DIR__ . '/HelperProxy.php');
 
         $this->autoloader->autoload('\bitExpert\PHPStan\Magento\Autoload\Helper\Proxy');
@@ -98,11 +97,12 @@ class_alias('\bitExpert\PHPStan\Magento\Autoload\HelperProxy', '\bitExpert\PHPSt
         $this->classLoader->expects(self::once())
             ->method('findFile')
             ->willReturn(false);
-        $this->storage->expects(self::atMost(2))
-            ->method('load')
-            ->willReturnOnConsecutiveCalls(null, __DIR__ . '/HelperProxy.php');
-        $this->storage->expects(self::once())
-            ->method('save');
+        $this->cache->expects(self::once())
+            ->method('getFile')
+            ->willReturn(null);
+        $this->cache->expects(self::once())
+            ->method('putFile')
+            ->willReturn(__DIR__ . '/HelperProxy.php');
 
         $this->autoloader->autoload('\bitExpert\PHPStan\Magento\Autoload\Helper\Proxy');
 
diff --git a/tests/bitExpert/PHPStan/Magento/Autoload/RegistrationUnitTest.php b/tests/bitExpert/PHPStan/Magento/Autoload/RegistrationUnitTest.php
index c14eea9..4b62478 100644
--- a/tests/bitExpert/PHPStan/Magento/Autoload/RegistrationUnitTest.php
+++ b/tests/bitExpert/PHPStan/Magento/Autoload/RegistrationUnitTest.php
@@ -12,9 +12,9 @@
 
 namespace bitExpert\PHPStan\Magento\Autoload;
 
+use bitExpert\PHPStan\Magento\Autoload\Cache\GeneratedFileCache;
 use bitExpert\PHPStan\Magento\Autoload\DataProvider\ClassLoaderProvider;
 use bitExpert\PHPStan\Magento\Autoload\DataProvider\ExtensionAttributeDataProvider;
-use PHPStan\Cache\Cache;
 use PHPUnit\Framework\TestCase;
 
 class RegistrationUnitTest extends TestCase
@@ -43,7 +43,7 @@ public function autoloadersCanRegisterAndUnregister(Autoloader $autoloader): voi
      */
     public function provideAutoloaders(): array
     {
-        $cache = new Cache($this->getMockBuilder(\PHPStan\Cache\CacheStorage::class)->getMock());
+        $cache = $this->createMock(GeneratedFileCache::class);
         $classLoader = $this->createMock(ClassLoaderProvider::class);
 
         return [

From 7e347077a8d12152e981fe863e7255cdad34e6de Mon Sep 17 00:00:00 2001
From: Michiel Gerritsen <michiel@controlaltdelete.nl>
Date: Wed, 2 Sep 2026 11:31:45 +0200
Subject: [PATCH 2/2] Cover makeDir branches in GeneratedFileCache

---
 .../Cache/GeneratedFileCacheUnitTest.php      | 24 +++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/tests/bitExpert/PHPStan/Magento/Autoload/Cache/GeneratedFileCacheUnitTest.php b/tests/bitExpert/PHPStan/Magento/Autoload/Cache/GeneratedFileCacheUnitTest.php
index 958b5b4..641bea3 100644
--- a/tests/bitExpert/PHPStan/Magento/Autoload/Cache/GeneratedFileCacheUnitTest.php
+++ b/tests/bitExpert/PHPStan/Magento/Autoload/Cache/GeneratedFileCacheUnitTest.php
@@ -93,4 +93,28 @@ public function addingFileToCacheFails(): void
 
         $this->cache->putFile('test.txt', 'Lorem ipsum');
     }
+
+    /**
+     * @test
+     */
+    public function existingCacheDirectoryIsReused(): void
+    {
+        $this->cache->putFile('test.txt', 'Lorem ipsum');
+        $writtenFilename = $this->cache->putFile('test.txt', 'Dolor sit amet');
+
+        self::assertSame('Dolor sit amet', file_get_contents($writtenFilename));
+    }
+
+    /**
+     * @test
+     */
+    public function addingFileToCacheFailsWhenCacheDirectoryCannotBeCreated(): void
+    {
+        $this->expectException(InvalidArgumentException::class);
+        $this->expectExceptionMessageMatches('#^Failed to create directory#');
+
+        $this->root->chmod(0000);
+
+        $this->cache->putFile('test.txt', 'Lorem ipsum');
+    }
 }