add phpstan strict

vendor/phpstan/extension-installer/README.md

@@ -0,0 +1,77 @@
+# PHPStan Extension Installer
+
+[![Build](https://github.com/phpstan/extension-installer/workflows/Build/badge.svg)](https://github.com/phpstan/extension-installer/actions)
+[![Latest Stable Version](https://poser.pugx.org/phpstan/extension-installer/v/stable)](https://packagist.org/packages/phpstan/extension-installer)
+[![License](https://poser.pugx.org/phpstan/extension-installer/license)](https://packagist.org/packages/phpstan/extension-installer)
+
+Composer plugin for automatic installation of [PHPStan](https://phpstan.org/) extensions.
+
+# Motivation
+
+```diff
+diff --git a/phpstan.neon b/phpstan.neon
+index db4e3df32e..2ca30fa20a 100644
+--- a/phpstan.neon
++++ b/phpstan.neon
+@@ -1,12 +1,3 @@
+-includes:
+-	- vendor/phpstan/phpstan-doctrine/extension.neon
+-	- vendor/phpstan/phpstan-doctrine/rules.neon
+-	- vendor/phpstan/phpstan-nette/extension.neon
+-	- vendor/phpstan/phpstan-nette/rules.neon
+-	- vendor/phpstan/phpstan-phpunit/extension.neon
+-	- vendor/phpstan/phpstan-phpunit/rules.neon
+-	- vendor/phpstan/phpstan-strict-rules/rules.neon
+-
+ parameters:
+ 	autoload_directories:
+ 		- %rootDir%/../../../build/SlevomatSniffs
+diff --git a/composer.json b/composer.json
+index 1b578dd624..f6ebf6e477 100644
+--- a/composer.json
++++ b/composer.json
+@@ -142,6 +142,7 @@
+ 		"jakub-onderka/php-parallel-lint": "1.0.0",
+ 		"justinrainbow/json-schema": "5.2.8",
+ 		"ondrejmirtes/mocktainer": "0.8",
++		"phpstan/extension-installer": "^1.0",
+ 		"phpstan/phpstan": "^0.11.7",
+ 		"phpstan/phpstan-doctrine": "^0.11.3",
+ 		"phpstan/phpstan-nette": "^0.11.1",
+```
+
+## Usage
+
+```bash
+composer require --dev phpstan/extension-installer
+```
+
+Starting from Composer 2.2.0 you'll get the following question:
+```
+phpstan/extension-installer contains a Composer plugin which is currently not in your allow-plugins config. See https://getcomposer.org/allow-plugins
+Do you trust "phpstan/extension-installer" to execute code and wish to enable it now? (writes "allow-plugins" to composer.json) [y,n,d,?]
+```
+
+Answer with `y` to allow the plugin.
+
+## Instructions for extension developers
+
+It's best (but optional) to set the extension's composer package [type](https://getcomposer.org/doc/04-schema.md#type) to `phpstan-extension` for this plugin to be able to recognize it and to be [discoverable on Packagist](https://packagist.org/explore/?type=phpstan-extension).
+
+Add `phpstan` key in the extension `composer.json`'s `extra` section:
+
+```json
+{
+  "extra": {
+    "phpstan": {
+      "includes": [
+        "extension.neon"
+      ]
+    }
+  }
+}
+```
+
+## Limitations
+
+The extension installer depends on Composer script events, therefore you cannot use `--no-scripts` flag.