Script to find classes/interfaces/traits with missing return types: ADD THEM TO YOUR SHIT.

find-missing-return-types.php

<?php

require_once  __DIR__ . '/vendor/autoload.php';

$namespace = 'PutYourProjectNamespaceHere\\';

foreach (new RegexIterator(new RecursiveIteratorIterator(new RecursiveDirectoryIterator(__DIR__ . '/src')), '/^.+\.php$/i', RecursiveRegexIterator::GET_MATCH) as $file) {
    require_once $file[0];
}

$symbols = array_merge(get_declared_classes(), get_declared_interfaces(), get_declared_traits());
$methods = [];

foreach ($symbols as $symbol) {
    foreach ((new \ReflectionClass($symbol))->getMethods() as $method) {
        if ($method->isConstructor()) {
            continue;
        }

        if ($method->getReturnType()) {
            continue;
        }

        if (0 !== strpos($method->getDeclaringClass()->getName(), $namespace)) {
            continue;
        }

        if (false !== strpos($method->getDocComment(), '@return void')) {
            continue;
        }

        $methods[] = $method->getDeclaringClass()->getName() . '#' . $method->getName();
    }
}

var_dump(array_values(array_unique($methods)));