Reflected class method returning type #8993

rogermedico · 2023-03-04T12:44:11Z

rogermedico
Mar 4, 2023

Hello everyone,

let's assume I have this chunk of code:

<?php declare(strict_types = 1);

Class A { 
    public function __construct() {}
	
    /** @return int */
    private function getInt(): int {return 1;} 
	
    /** @return string */
    private function getString(): string {return 'string';} 
}

Class Reflection {
    public function __construct() {}
	
    /**
     * @template T of object
     * @param class-string<T>|T $class
     * @param string $name
     * @return mixed    <-- THIS TYPE HAS TO BE THE RETURNING TYPE OF METHOD NAME CALLED FROM CLASS PASSED
     */
    public function callMethod($class, $name)
    {
	$reflectedClass = new ReflectionClass($class);
        $method = $reflectedClass->getMethod($name);
        $method->setAccessible(true);
        return $method->invoke(is_object($class) ? $class : new $class());
    } 
}

/**
 * @param int $int
 * @return int
 */
function returnInt(int $int): int {return $int;} 

/**
 * @param string $string
 * @return string
 */
function returnString(string $string) {return $string;} 

$reflection = new Reflection();

$int = $reflection->callMethod(A::class, 'getInt');
$string = $reflection->callMethod(A::class, 'getString');

echo (returnInt($int));

echo (returnString($string));

How I can determine the returning type of a reflected class method call and set that type as a returning type of the method "callMethod"? Note that methods in class A are private and cannot be called directly.

The lasts calls of returnInt and returnString fails because callMethod returns mixed.

Example: https://phpstan.org/r/5733e54a-de8c-4018-9fb4-c62b03f335d2 in this example detects unused functions in lines 7 and 10 but this is not the problem.

Thank you in advance

/roger