Add extension for PHPStan to support checkUninitializedProperties

Author: mfn

CHANGELOG.md

@@ -2,6 +2,9 @@
 
 All notable changes to `data-transfer-object` will be documented in this file
 
+## Unreleased
+- Add PHPStan extension to support `checkUninitializedProperties: true`
+
 ## 2.2.1 - 2020-05-13
 
 - Validator for typed 7.4 properties (#109)

README.md

@@ -422,6 +422,22 @@ $dto = new PostData([
 $dto->toArray(); // ['content' => 'blah blah']
 ```
 
+### PHPStan
+
+If you're using [phpstan](https://phpstan.org/) and set `checkUninitializedProperties: true`, phpstan by default doesn't understand that the DTO properties will always be correctly initialized.
+
+To help with that, this package provides a rule you can add to your `.neon` config file:
+```yaml
+services:
+  -
+    class: Spatie\DataTransferObject\PHPstan\PropertiesAreAlwaysInitializedExtension
+    tags:
+      - phpstan.properties.readWriteExtension
+#…
+parameters:
+  checkUninitializedProperties: true
+```
+
 ### Testing
 
 ``` bash

composer.json

@@ -23,6 +23,9 @@
         "larapack/dd": "^1.0",
         "phpunit/phpunit": "^7.0"
     },
+    "suggest": {
+        "phpstan/phpstan": "Take advantage of checkUninitializedProperties with \\Spatie\\DataTransferObject\\PHPstan\\PropertiesAreAlwaysInitializedExtension"
+    },
     "autoload": {
         "psr-4": {
             "Spatie\\DataTransferObject\\": "src"

src/PHPstan/PropertiesAreAlwaysInitializedExtension.php

@@ -0,0 +1,27 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Spatie\DataTransferObject\PHPstan;
+
+use PHPStan\Reflection\PropertyReflection;
+use PHPStan\Rules\Properties\ReadWritePropertiesExtension;
+use Spatie\DataTransferObject\DataTransferObject;
+
+class PropertiesAreAlwaysInitializedExtension implements ReadWritePropertiesExtension
+{
+    public function isAlwaysRead(PropertyReflection $property, string $propertyName): bool
+    {
+        return false;
+    }
+
+    public function isAlwaysWritten(PropertyReflection $property, string $propertyName): bool
+    {
+        return false;
+    }
+
+    public function isInitialized(PropertyReflection $property, string $propertyName): bool
+    {
+        return $property->getDeclaringClass()->isSubclassOf(DataTransferObject::class);
+    }
+}