getMockBuilder(NotFoundResponse::class) ->setMethods(['renderPage']) ->getMock(); /** @var ResponseInterface|MockObject $response */ $response = $this->getMockForAbstractClass(ResponseInterface::class); /** @var RequestHandlerInterface|MockObject $handler */ $handler = $this->getMockForAbstractClass(RequestHandlerInterface::class); /** @var ServerRequestInterface|MockObject $request */ $request = $this->getMockForAbstractClass(ServerRequestInterface::class); $middleware->expects($this->once()) ->method('renderPage') ->willReturn($response); $handler->expects($this->never()) ->method('handle'); $middleware->process($request, $handler); } }