如何将@WebMvcTest用于使用自动装配的ConversionService的Controller？

Question

在春季启动应用程序,我有两个的POJO,Foo和Bar和BarToFooConverter,它看起来像:

@Component
public class BarToFooConverter implements Converter<Bar, Foo> {
    @Override
    public Foo convert(Bar bar) {
        return new Foo(bar.getBar());
    }
}

我还有一个使用转换器的控制器:

@RestController("test")
public class TestController {
    @Autowired
    private ConversionService conversionService;

    @RequestMapping(method = RequestMethod.PUT)
    @ResponseBody
    public Foo put(@RequestBody Bar bar) {
        return conversionService.convert(bar, Foo.class);
    }
}

我想测试这个控制器@WebMvcTest,例如:

@WebMvcTest
@RunWith(SpringRunner.class)
public class TestControllerTest {
    @Autowired
    private MockMvc mockMvc;

    @Test
    public void test() throws Exception {
        mockMvc.perform(
                put("/test")
                        .contentType(MediaType.APPLICATION_JSON)
                        .content("{\"bar\":\"test\"}"))
                .andExpect(status().isOk());
    }
}

但是当我运行这个时,我发现我BarToFooConverter没有注册ConversionService:

Caused by: org.springframework.core.convert.ConverterNotFoundException: No converter found capable of converting from type [com.example.demo.web.Bar] to type [com.example.demo.web.Foo]
    at org.springframework.core.convert.support.GenericConversionService.handleConverterNotFound(GenericConversionService.java:324)
    at org.springframework.core.convert.support.GenericConversionService.convert(GenericConversionService.java:206)
    at org.springframework.core.convert.support.GenericConversionService.convert(GenericConversionService.java:187)
    at com.example.demo.web.TestController.put(TestController.java:15)

这似乎是有道理的,因为根据Javadoc:

使用此批注将禁用完全自动配置,而是仅应用与MVC测试相关的配置(即@ Controller,@ ControllerAdvice,@ JsonComponent Filter,WebMvcConfigurer和HandlerMethodArgumentResolver bean,但不包括@Component,@ Service或@Repository bean).

但是,参考指南略有不同,说它@WebMvcTest 确实包括Converters:

@WebMvcTest自动配置Spring MVC基础结构并将扫描的bean限制为@ Controller,@ ControllerAdvice,@ JsonComponent,Converter,GenericConverter,Filter,WebMvcConfigurer和HandlerMethodArgumentResolver.使用此批注时,不会扫描常规@Component bean.

这里的参考指南似乎不正确 - 或者我正在注册我的Converter错误？

我也试过ConversionService在我的测试中嘲笑:

@WebMvcTest
@RunWith(SpringRunner.class)
public class TestControllerTest {
    @Autowired
    private MockMvc mockMvc;

    @MockBean
    private ConversionService conversionService;

    @Test
    public void test() throws Exception {
        when(conversionService.convert(any(Bar.class), eq(Foo.class))).thenReturn(new Foo("test"));

        mockMvc.perform(
                put("/test")
                        .contentType(MediaType.APPLICATION_JSON)
                        .content("{\"bar\":\"test\"}"))
                .andExpect(status().isOk());
    }
}

但现在Spring抱怨我的模拟ConversionService覆盖了默认模拟:

Caused by: java.lang.IllegalStateException: @Bean method WebMvcConfigurationSupport.mvcConversionService called as a bean reference for type [org.springframework.format.support.FormattingConversionService] but overridden by non-compatible bean instance of type [org.springframework.core.convert.ConversionService$$EnhancerByMockitoWithCGLIB$$da4e303a]. Overriding bean of same name declared in: null
    at org.springframework.context.annotation.ConfigurationClassEnhancer$BeanMethodInterceptor.obtainBeanInstanceFromFactory(ConfigurationClassEnhancer.java:402)
    at org.springframework.context.annotation.ConfigurationClassEnhancer$BeanMethodInterceptor.intercept(ConfigurationClassEnhancer.java:361)
    ...

理想情况下,我想使用我的原始方法,在我的测试中使用真正的Converter而不是模拟ConversionService,但是@WebMvcTest为了限制启动的组件的范围,所以我也尝试includeFilter在@WebMvcTest注释中使用an :

@WebMvcTest(includeFilters = @ComponentScan.Filter(type = FilterType.REGEX, pattern = "com.example.demo.web.Bar*"))

但它仍然失败,原始的'无转换器发现能够转换...'错误消息.

这感觉就像是一个非常常见的要求 - 我错过了什么？

Answer 1

您可以通过带注释的方法手动注册转换器@Before。您所要做的就是注入GenericConversionService并调用addConverter(new BarToFooConverter())以使转换器可解析。在这种情况下，您可以摆脱模拟部分。您的测试可能如下所示：

import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.autoconfigure.web.servlet.WebMvcTest;
import org.springframework.core.convert.support.GenericConversionService;
import org.springframework.http.MediaType;
import org.springframework.test.context.junit4.SpringRunner;
import org.springframework.test.web.servlet.MockMvc;

import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.put;
import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;

@WebMvcTest
@RunWith(SpringRunner.class)
public class TestControllerTest {

    @Autowired
    private MockMvc mockMvc;

    @Autowired
    private GenericConversionService conversionService;

    @Before
    public void setup() {
        conversionService.addConverter(new BarToFooConverter());
    }

    @Test
    public void test() throws Exception {
        mockMvc.perform(
                put("/test")
                        .contentType(MediaType.APPLICATION_JSON)
                        .content("{\"bar\":\"test\"}"))
                .andExpect(status().isOk());
    }
}

替代解决方案：Spring Boot 从1.4.0版本开始提供了一系列与测试相关的自动配置，其中一个自动配置是@AutoConfigureMockMvc配置MockMvc与注入的转换器组件配合良好的组件。