CI: add PHPStan to detect additional PHP issues

Author: glaubinix

.github/workflows/php.yml

@@ -43,3 +43,8 @@ jobs:
         run: ./vendor/bin/php-cs-fixer fix --dry-run --diff
         env:
           PHP_CS_FIXER_IGNORE_ENV: 1
+
+      - name: PHPStan
+        run: ./vendor/bin/phpstan analyze src --no-progress
+        env:
+          PHP_CS_FIXER_IGNORE_ENV: 1

composer.json

@@ -25,7 +25,8 @@
         "php-http/mock-client": "^1.0",
         "guzzlehttp/psr7": "^1.2",
         "cache/array-adapter": "^1.1.0",
-        "friendsofphp/php-cs-fixer": "^3.0"
+        "friendsofphp/php-cs-fixer": "^3.0",
+        "phpstan/phpstan": "^1.2"
     },
     "autoload": {
         "psr-4": { "PrivatePackagist\\ApiClient\\": "src/" }

phpstan.neon

@@ -0,0 +1,5 @@
+parameters:
+    level: 0
+    paths:
+        - src
+        - tests