MockContainer, not used, system function mock need create in per test case.

MockContainer.php

<?php
namespace Fwlib\Test;

use Fwlib\Base\AbstractServiceContainer;
use malkusch\phpmock\Mock;

/**
 * Container of system function mocks
 *
 * @copyright   Copyright 2015 Fwolf
 * @license     http://www.gnu.org/licenses/lgpl.html LGPL-3.0+
 */
class MockContainer extends AbstractServiceContainer
{
    /**
     * Get full qualified function name
     *
     * @param   string  $namespace
     * @param   string  $function
     * @return  string
     */
    protected function getFullName($namespace, $function)
    {
        $namespace = trim($namespace, '\\');

        return "$namespace\\$function";
    }


    /**
     * @param   string  $namespace
     * @param   string  $function
     * @return  Mock
     */
    public function getMock($namespace, $function)
    {
        $fullName = $this->getFullName($namespace, $function);

        return isset($this->serviceInstance[$fullName])
            ? $this->serviceInstance[$fullName]
            : null;
    }


    /**
     * Register a mock instance
     *
     * @param   string  $namespace
     * @param   string  $function
     * @param   Mock    $mock
     * @return  static
     */
    public function registerMock($namespace, $function, $mock)
    {
        $fullName = $this->getFullName($namespace, $function);

        $this->registerInstance($fullName, $mock);

        return $this;
    }
}