Phunkie PHPStan Extension

PHPStan extensions for the Phunkie functional programming library.

Installation

composer require --dev phunkie/phpstan

The extension is automatically registered via PHPStan's extension mechanism.

What it provides

Generic Type Transformation

Phunkie uses container types (IO, Option, Validation, etc.) that transform their type parameters through method calls. PHPStan often loses this type information when closures are involved.

This extension provides a single configurable resolver that handles common patterns:

Pattern	Description	Example
wrap	F<A> → F<Wrapper<Fixed, A>>	IO<A>::attempt() → IO<Validation<Throwable, A>>
map	F<A>.f(A→B) → F<B>	IO<A>::map(fn) → IO<B>
pair	F<A>.f(A→B) → F<Pair<A, B>>	IO<A>::zipWith(fn) → IO<Pair<A, B>>
preserve	F<A>.method() → F<A>	Methods that don't change type

Configuration

The extension is configured in extension.neon:

services:
    -
        class: Phunkie\PHPStan\GenericMethodReturnTypeExtension
        arguments:
            targetClass: Phunkie\Effect\IO\IO
            methods:
                -
                    method: attempt
                    pattern: wrap
                    wrapper: Phunkie\Validation\Validation
                    fixedTypes: [Throwable]
                -
                    method: map
                    pattern: map
        tags:
            - phpstan.broker.dynamicMethodReturnTypeExtension

Covariant Type Support

The Phunkie core library includes @template-covariant annotations so that:

• Success<A> is a Validation<never, A> (compatible with any Validation<E, A>)
• Failure<E> is a Validation<E, never> (compatible with any Validation<E, A>)

Requirements

• PHP 8.2+
• PHPStan 2.0+
• Phunkie 1.0+

License

MIT