Add Mixin attribute

Author: carlos-granados

Diff for: README.md

@@ -100,6 +100,7 @@ These are the available attributes and their corresponding PHPDoc annotations:
 | [Internal](https://github.com/php-static-analysis/attributes/blob/main/doc/Internal.md)                           | `@internal`               |
 | [IsReadOnly](https://github.com/php-static-analysis/attributes/blob/main/doc/IsReadOnly.md)                       | `@readonly`               |
 | [Method](https://github.com/php-static-analysis/attributes/blob/main/doc/Method.md)                               | `@method`                 |
+| [Mixin](https://github.com/php-static-analysis/attributes/blob/main/doc/Mixin.md)                                 | `@mixin`                  |
 | [Param](https://github.com/php-static-analysis/attributes/blob/main/doc/Param.md)                                 | `@param`                  |
 | [Property](https://github.com/php-static-analysis/attributes/blob/main/doc/Property.md)                           | `@property` `@var`        |
 | [PropertyRead](https://github.com/php-static-analysis/attributes/blob/main/doc/PropertyRead.md)                   | `@property-read`          |

Diff for: composer.json

@@ -24,8 +24,8 @@
     "prefer-stable": true,
     "require": {
         "php": ">=8.0",
-        "php-static-analysis/attributes": "^0.1.9 || dev-main",
-        "php-static-analysis/node-visitor": "^0.1.9 || dev-main",
+        "php-static-analysis/attributes": "^0.1.10 || dev-main",
+        "php-static-analysis/node-visitor": "^0.1.10 || dev-main",
         "phpstan/phpstan": "^1.8"
     },
     "require-dev": {

Diff for: tests/MixinAttributeTest.php

@@ -0,0 +1,38 @@
+<?php
+
+namespace test\PhpStaticAnalysis\PHPStanExtension;
+
+class MixinAttributeTest extends BaseAttributeTestCase
+{
+    public function testClassMixinAttribute(): void
+    {
+        $errors = $this->analyse(__DIR__ . '/data/Mixin/ClassMixinAttribute.php');
+        $this->assertCount(0, $errors);
+    }
+
+    public function testInterfaceMixinAttribute(): void
+    {
+        $errors = $this->analyse(__DIR__ . '/data/Mixin/InterfaceMixinAttribute.php');
+        $this->assertCount(0, $errors);
+    }
+
+    public function testTraitMixinAttribute(): void
+    {
+        $errors = $this->analyse(__DIR__ . '/data/Mixin/TraitMixinAttribute.php');
+        $this->assertCount(0, $errors);
+    }
+
+    public function testInvalidClassMixinAttribute(): void
+    {
+        $errors = $this->analyse(__DIR__ . '/data/Mixin/InvalidClassMixinAttribute.php');
+
+        $expectedErrors = [
+            'PHPDoc tag @mixin contains unknown class test\PhpStaticAnalysis\PHPStanExtension\data\Mixin\count.' => 7,
+            'PHPDoc tag @mixin has invalid value (): Unexpected token "\n * ", expected type at offset 13' => 7,
+            'Parameter #1 ...$params of attribute class PhpStaticAnalysis\Attributes\Mixin constructor expects string, int given.' => 7,
+            'Attribute class PhpStaticAnalysis\Attributes\Mixin does not have the method target.' => 11,
+        ];
+
+        $this->checkExpectedErrors($errors, $expectedErrors);
+    }
+}

Diff for: tests/data/Mixin/ClassMixinAttribute.php

@@ -0,0 +1,36 @@
+<?php
+
+namespace test\PhpStaticAnalysis\PHPStanExtension\data\Mixin;
+
+use PhpStaticAnalysis\Attributes\Mixin;
+
+class ClassMixinAttribute
+{
+    public function proxied(): void
+    {
+    }
+}
+
+class MyClass
+{
+}
+
+class Another
+{
+}
+
+#[Mixin('ClassMixinAttribute')] // this is the proxied class
+#[Mixin(
+    'MyClass',
+    'Another',
+)]
+class ClassMixinAttributeProxy
+{
+    public function __call(string $name, mixed ...$arguments): void
+    {
+        (new ClassMixinAttribute())->$name(...$arguments);
+    }
+}
+
+$proxy = new ClassMixinAttributeProxy();
+$proxy->proxied();

Diff for: tests/data/Mixin/InterfaceMixinAttribute.php

@@ -0,0 +1,14 @@
+<?php
+
+namespace test\PhpStaticAnalysis\PHPStanExtension\data\Mixin;
+
+use PhpStaticAnalysis\Attributes\Mixin;
+
+#[Mixin('AClass')]
+interface InterfaceMixinAttribute
+{
+}
+
+class AClass
+{
+}

Diff for: tests/data/Mixin/InvalidClassMixinAttribute.php

@@ -0,0 +1,16 @@
+<?php
+
+namespace test\PhpStaticAnalysis\PHPStanExtension\data\Mixin;
+
+use PhpStaticAnalysis\Attributes\Mixin;
+
+#[Mixin(0)]
+#[Mixin('count($a)')]
+class InvalidClassMixinAttribute
+{
+    #[Mixin('A')]
+    public function getName(): string
+    {
+        return "John";
+    }
+}

Diff for: tests/data/Mixin/TraitMixinAttribute.php

@@ -0,0 +1,14 @@
+<?php
+
+namespace test\PhpStaticAnalysis\PHPStanExtension\data\Mixin;
+
+use PhpStaticAnalysis\Attributes\Mixin;
+
+class Other
+{
+}
+
+#[Mixin('Other')]
+trait TraitMixinAttribute
+{
+}