如何模拟 Spring WebClient 和构建器

Question

我正在尝试模拟 Spring WebClient 并且遇到了 WebClient.builder() 模拟的问题。到目前为止我在测试中定义的模拟没有被使用，我认为是因为这个构建器没有返回我的模拟 WebClient。如何让 builder 退回我的模型？

WebClient webClient = WebClient.builder()
                .exchangeStrategies(ExchangeStrategies.builder()
                .codecs(configurer -> configurer
                        .defaultCodecs()
                        .maxInMemorySize(16 * 1024 * 1024))
                .build())
                .clientConnector(new ReactorClientHttpConnector(HttpClient.newConnection().compress(true)))
                .build();

WebClient 就是这样使用的：

response = webClient
            .get()
            .uri(URLDecoder.decode(someEndpoint.replace("\"", ""), CLIENT_ENCODING))
            .header(AUTHORIZATION, BEARER + accessToken)
            .accept(MediaType.APPLICATION_JSON)
            .retrieve().bodyToMono(JsonNode.class).block();

当我遵循以下解决方案时，我没有看到模拟有任何问题：How to mock Spring WebFlux WebClient? 但没有使用模拟。如何模拟构建器/从构建器返回我的模拟？

Answer 1

您需要模拟WebClient 的静态方法builder()。事实上，如果这个方法没有被模拟，mockito 就不能编辑这个方法的行为。因此，您的模拟 webClient 未被使用。为此，如果您使用 maven，则需要将此依赖项包含在您的 pom.xml 中。

<dependency>
    <groupId>org.mockito</groupId>
    <artifactId>mockito-inline</artifactId>
    <version>3.4.6</version>
    <scope>test</scope>
</dependency>

这将在Mockito 上提供mockStatic() 方法，可以像这样使用：

MockedStatic<WebClient> webClientStatic = Mockito.mockStatic(WebClient.class);
webClientStatic.when(WebClient::builder).thenReturn(webClientBuilder);

webClientBuilder 必须被模拟，因为我们需要更改其方法 build() 的行为以返回模拟的 webClient。

Mockito.when(webClientBuilder.build()).thenReturn(mockedWebClient);

在一个代码中恢复所有内容：

import org.junit.Assert;
import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.mockito.Mock;
import org.mockito.Mockito;
import org.mockito.junit.MockitoJUnitRunner;
import org.springframework.http.client.reactive.ReactorClientHttpConnector;
import org.springframework.web.reactive.function.client.ExchangeStrategies;
import org.springframework.web.reactive.function.client.WebClient;
import reactor.netty.http.client.HttpClient;
import org.mockito.MockedStatic;

@RunWith(MockitoJUnitRunner.class)
public class WebClientTest {

    @Mock
    private WebClient.Builder webClientBuilder;

    @Mock
    private WebClient mockedWebClient;

    @Before
    public void setup() {
        Mockito.when(webClientBuilder.exchangeStrategies(Mockito.any(ExchangeStrategies.class))).thenReturn(webClientBuilder);
        Mockito.when(webClientBuilder.clientConnector(Mockito.any(ReactorClientHttpConnector.class))).thenReturn(webClientBuilder);
        Mockito.when(webClientBuilder.build()).thenReturn(mockedWebClient);
    }

    @Test
    public void testWebClient() {
        final MockedStatic<WebClient> webClientStatic = Mockito.mockStatic(WebClient.class);
        webClientStatic.when(WebClient::builder).thenReturn(webClientBuilder);

        final WebClient webClient = WebClient.builder()
                .exchangeStrategies(ExchangeStrategies.builder()
                        .codecs(configurer -> configurer
                                .defaultCodecs()
                                .maxInMemorySize(16 * 1024 * 1024))
                        .build())
                .clientConnector(new ReactorClientHttpConnector(HttpClient.newConnection().compress(true)))
                .build();

        //It throws error if webClient is not mockedWebClient
        Assert.assertEquals(webClient, mockedWebClient);
    }
}

你可以测试一下。