Mono.doOnError() 反应器块单元测试答案

【问题标题】：Mono.doOnError() reactor block unit testMono.doOnError() 反应器块单元测试
【发布时间】：2019-08-26 14:40:58
【问题描述】：

我有一个使用 spring webflux 和 reactor 的休息控制器，我正在为控制器编写单元测试。请在下面找到代码 sn-ps 并帮助我编写单元测试方法来测试 .doOnError 块。

我尝试使用 Mockito 引发异常

doThrow(CriticalException.class) .when(myService).myMethod(object);

This is my unit test


StepVerifier.create(
Mono.just(
                webTestClient.post() 
                       .uri("/endpoint")
                       .accept(MediaType.APPLICATION_JSON) 


                       .body(BodyInserters.fromObject(requestJson)) //Set the body of the request to the given synchronous Object
                                            //Returns:a Mono with the response
        //Act
                       .exchange()  //Perform the exchange 
        //Assert        
                       .expectStatus().isOk() 
                       .expectBody(Agreement.class)
                       .returnResult()
                       .getResponseBody()))
                .expectNextMatches(agreementResponse -> {
                        assertNotNull(agreementResponse.getAgreementParticipant());
                        return true; 
                }) 
                .expectComplete()
                .verify();

这是我的控制器

return Mono.fromCallable(() -> { 
            myService.myMethod(object);
            return object;
        }).log().subscribeOn(Schedulers.elastic())
                .map(p -> ResponseEntity.ok(p))
                .defaultIfEmpty(ResponseEntity.notFound().build())
                .doOnError(e -> { 
                    LOGGER.error(LOG_FORMAT, e.getMessage(), e.getStackTrace());                
                }); 


Mockito is not returning exception while myService.myMethod(object) is been called.
Please suggest proper way to write test for .defaultIfEmpty and .doOnError blocks

【问题讨论】：

标签： unit-testing mockito spring-webflux reactor

【解决方案1】：

在模拟你的myService.myMethod(object) 时不要抛出CriticalException.class，而是返回一个包裹在Mono 中的exception

例如：

Mockito.doReturn(Mono.error(Exception::new)).when(service).callableMethod();

在下面找到示例代码sn-p

import org.junit.Test;
import org.mockito.Mock;
import org.mockito.Mockito;
import reactor.core.publisher.Mono;
import reactor.test.StepVerifier;

class Service {

    public Mono<String> callableMethod() {

        return Mono.just("1");
    }
}

class Controller {

    private Service service;

    public Controller(Service service) {

        this.service = service;
    }

    public Mono<String> endpoint() {

        return service.callableMethod().doOnError(throwable -> {
            System.out.println("throwable = " + throwable);
        });
    }
}

public class TestClass {

    @Mock
    private Service service = Mockito.mock(Service.class);

    @Test
    public void controllerTest() {

        Mockito.doReturn(Mono.error(Exception::new)).when(service).callableMethod();

        StepVerifier.create(new Controller(service).endpoint()).verifyError();
    }
}

【讨论】：