shouldReceive('encode') ->with('jpg', 87) ->once() ->andReturnSelf(); $image->shouldReceive('getEncoded') ->once() ->andReturn($encodedContent); $command = new StreamCommand(['jpg', 87]); $result = $command->execute($image); $this->assertTrue($result); $this->assertTrue($command->hasOutput()); $output = $command->getOutput(); $this->assertInstanceOf('Psr\Http\Message\StreamInterface', $output); $this->assertEquals($encodedContent, (string)$output); } }