Clinner\Command\Tests\CallbackTest::testGetOutput PHP Method

    public function testGetOutput()
    {
        $closure = function () {
            echo 'Some nifty output';
        };
        $callback = new Callback($closure);
        // Output must be null before the command is run
        $this->assertNull($callback->getOutput());
        $callback->run();
        // Output must be a string after the command is run with the given $closure
        $this->assertEquals('Some nifty output', $callback->getOutput());
    }