# $this in Static Context
# Detects $this used inside static methods in PHP
id: this-in-static-context
name: $this Should Not Be Used in Static Context
severity: error
category: reliability
defect_class: correctness
inline_tier: blocking
language: php

message: "$this should not be used in a static method context"

description: |
  Using $this inside a static method causes a fatal error in PHP.
  Static methods don't have access to instance properties.
  Use self:: for static properties or remove the static modifier.

  ✅ FIX: Use self:: for static access or remove static modifier

  ```php
  class MyClass {
      private static $staticVar;
      
      public static function getStatic() {
          return self::$staticVar;  // Correct - use self::
      }
      
      public function getInstance() {
          return $this->instanceVar;  // Correct - instance method
      }
  }
  ```

query: |
  (method_declaration
    (modifiers
      "static")
    body: (compound_statement
      ((variable_name) @THIS
        (#eq? @THIS "$this"))))

metavars:
  - THIS
  - VAR

tags:
  - reliability
  - php
  - fatal-error
  - oop

examples:
  bad: |
    class MyClass {
        private $name;
        
        public static function getName() {
            return $this->name;  // FATAL ERROR - $this in static context
        }
    }

  good: |
    class MyClass {
        private static $name;
        
        public static function getName() {
            return self::$name;  // GOOD - use self::
        }
        
        public function getName() {
            return $this->name;  // GOOD - instance method
        }
    }

has_fix: false