type-inference.md

Type Inference

All type inference capabilities of this extension are summarised below:

Dynamic Static Method Return Type Extensions

ReflectionHelperGetPrivateMethodInvokerReturnTypeExtension

This extension provides precise return type to ReflectionHelper's static getPrivateMethodInvoker() method. Since PHPStan's dynamic return type extensions work on classes, not traits, this extension is on by default in test cases extending CodeIgniter\Test\CIUnitTestCase. To make this work, you should be calling the method statically:

For example, we're accessing the private method:

class Foo
{
    private static function privateMethod(string $value): bool
    {
        return true;
    }
}

Before

public function testSomePrivateMethod(): void
{
    $method = self::getPrivateMethodInvoker(new Foo(), 'privateMethod');
    \PHPStan\dumpType($method); // Closure(mixed ...): mixed
}

After

public function testSomePrivateMethod(): void
{
    $method = self::getPrivateMethodInvoker(new Foo(), 'privateMethod');
    \PHPStan\dumpType($method); // Closure(string): bool
}

Note

If you are using ReflectionHelper outside of testing, you can still enjoy the precise return types by adding a service for the class using this trait. In your phpstan.neon (or phpstan.neon.dist), add the following to the services schema:

-
 class: CodeIgniter\PHPStan\Type\ReflectionHelperGetPrivateMethodInvokerReturnTypeExtension
 tags:
   - phpstan.broker.dynamicStaticMethodReturnTypeExtension
 arguments:
   class: <Fully qualified class name of class using ReflectionHelper>