How can I test my Middleware?

Questions Mezzio
1

In my handlers I return JsonResponse

For example:

public function handle(ServerRequestInterface $request) : ResponseInterface
{
    $data = [
       // ...
    ];
    return new JsonResponse($data);
}

Then I have a ResponseFormatterMiddleware, which slightly changes response format:

public function process(ServerRequestInterface $request, RequestHandlerInterface $handler): ResponseInterface
{
    $response = $handler->handle($request);

    if ($array = $this->getArray($response)) {

        $formatType = $request->getQueryParams()['format'] ?? null;
        $formatType = $formatType ? mb_strtolower($formatType) : null;

        if ($formatType === 'xml') {
            return new XmlResponse($this->toXml($array));
        }

        if ($formatType === 'txt') {
            return new TextResponse($this->toTxt($array));
        }

        return new JsonResponse([$this->rootElement => $array]);
    }

    return $response;
}

Now I can’t test it. Ok, I spied how others are testing middlewares:

public function test()
{
    $request = $this->prophesize(ServerRequestInterface::class);

    $handler = $this->prophesize(RequestHandlerInterface::class);
    $handler->handle($request->reveal())->will([$this->response, 'reveal']);

    $result = $this->middleware->process($request->reveal(), $handler->reveal());

    $this->assertSame($this->response->reveal(), $result);
}

Well, the test passes, but it does not test anything.
I want to mock the request and compare it with the answer.

public function test()
{
    $request = $this->prophesize(ServerRequestInterface::class);

    $this->stream->getContents()->willReturn('{}');
    $request->getBody()->willReturn($this->stream);

    // $request->reveal()->getBody()->getContents() - {}, ok

    $handler = $this->prophesize(RequestHandlerInterface::class);
    $handler->handle($request->reveal())->will([$this->response, 'reveal']);

    $result = $this->middleware->process($request->reveal(), $handler->reveal());

    // $result->getBody() - null, not ok

    $this->assertEquals('{"main": "null"}', $request->getBody()->getContents());
}

Why can’t I get a response from my Middleware?

2

ok, after small research, I understood that necessary mocked all parameters used.

    /** @var StreamInterface|ObjectProphecy $stream */
    $stream = $this->prophesize(StreamInterface::class);
    $stream->getContents()->willReturn(json_encode(['test' => 'vasa']));

    /** @var ResponseInterface|ObjectProphecy $request */
    $response = $this->prophesize(ResponseInterface::class);
    $response->getBody()->will([$stream, 'reveal']);

    /** @var ServerRequestInterface|ObjectProphecy $request */
    $request = $this->prophesize(ServerRequestInterface::class);
    $request->getMethod()->willReturn(RequestMethod::METHOD_GET);
    $request->getQueryParams()->willReturn(['format' => 'xml']);

    /** @var RequestHandlerInterface|ObjectProphecy $handler */
    $handler = $this->prophesize(RequestHandlerInterface::class);
    $handler->handle($request->reveal())->will([$response, 'reveal']);

    $middleware = new ResponseFormatterMiddleware();

    $result = $middleware->process($request->reveal(), $handler->reveal());

    var_dump($result->getBody()->getContents());

Now I’m looking elegant solution for this.