TestCase.php

<?php

namespace Clue\React\Tests\Sse;

use PHPUnit\Framework\TestCase as BaseTestCase;

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

class TestCase extends BaseTestCase
{
    protected function expectCallableOnce()
    {
        $mock = $this->createCallableMock();

        $mock
            ->expects($this->once())
            ->method('__invoke');

        return $mock;
    }

    protected function createCallableMock()
    {
        if (method_exists('PHPUnit\Framework\MockObject\MockBuilder', 'addMethods')) {
            // PHPUnit 9+
            return $this->getMockBuilder('stdClass')->addMethods(array('__invoke'))->getMock();
        } else {
            // legacy PHPUnit 4 - PHPUnit 8
            return $this->getMockBuilder('stdClass')->setMethods(array('__invoke'))->getMock();
        }
    }
}