如何从spring启动测试中使用ApplicationContextRunner测试@ConfigurationProperties？

Question

我需要测试使用@ConfigurationProperties bean的自动配置类。我正在使用中记录的ApplicationContextRunnerhttps://docs.spring.io/spring-boot/docs/current/reference/html/spring-boot-features.html#boot-具有测试自动配置功能，可以加快测试速度，避免在每个变体之间启动servlet容器。但是，使用@AutoconfigurationProperties注释的bean不会使用注入ApplicationContextRunner的值填充。

我怀疑我遇到了类似https://stackoverflow.com/a/56023100/1484823问题

@ConfigurationProperties不由您在测试中构建的应用程序上下文管理，尽管它们将在应用程序启动时加载，因为您的应用程序主类上有@EnableConfigurationProperties。

如何使用ApplicationContextRunner启用对@ConfigurationProperties的支持？

这里是相应的代码

    @Test
    void ServiceDefinitionMapperPropertiesAreProperlyLoaded() {
        ApplicationContextRunner contextRunner = new ApplicationContextRunner()
            .withConfiguration(AutoConfigurations.of(
                SingleServiceDefinitionAnswerAutoConfig.class,
                DynamicCatalogServiceAutoConfiguration.class
            ))
//          .withPropertyValues(DynamicCatalogProperties.OPT_IN_PROPERTY + "=true") //Not sure why this seems ignored
            .withSystemProperties(DynamicCatalogConstants.OPT_IN_PROPERTY + "=true",
                ServiceDefinitionMapperProperties.PROPERTY_PREFIX
                +ServiceDefinitionMapperProperties.SUFFIX_PROPERTY_KEY+ "=suffix")
        ;
        contextRunner.run(context -> {
            assertThat(context).hasSingleBean(ServiceDefinitionMapperProperties.class);
            ServiceDefinitionMapperProperties serviceDefinitionMapperProperties
                = context.getBean(ServiceDefinitionMapperProperties.class);
            assertThat(serviceDefinitionMapperProperties.getSuffix()).isEqualTo("suffix");
        });
    }

它失败于：

 org.opentest4j.AssertionFailedError: 
Expecting:
 <"">
to be equal to:
 <"suffix">
but was not.
Expected :suffix
Actual   :
<Click to see difference>
    at org.springframework.cloud.appbroker.autoconfigure.DynamicCatalogServiceAutoConfigurationTest

public class DynamicCatalogServiceAutoConfiguration {

[...]

    @Bean
    @ConfigurationProperties(prefix=ServiceDefinitionMapperProperties.PROPERTY_PREFIX, ignoreUnknownFields = false)
    public ServiceDefinitionMapperProperties serviceDefinitionMapperProperties() {
        return new ServiceDefinitionMapperProperties();
    }
[...]
}

完整资料来源可于https://github.com/orange-cloudfoundry/osb-cmdb-spike/blob/0da641e5f2f811f48b0676a25c8cbe97895168d1/spring-cloud-app-broker-autoconfigure/src/test/java/org/springframework/cloud/appbroker/autoconfigure/DynamicCatalogServiceAutoConfigurationTest.java#L89-L107

附言：我正要把一个问题提交给https://github.com/spring-projects/spring-boot/issues 建议文档增强，以警告ApplicationContext中的此类限制，并询问如何启用对@ConfigurationProperties的支持。遵循以下指南：https://raw.githubusercontent.com/spring-projects/spring-boot/master/.github/ISSUE_TEMPLATE.md，我首先要确保我没有误解这个问题。

Answer 1

如果您想在测试中填充一个注释为@ConfigurationProperties类的bean，并且您通常依赖于注释为@EnableConfigurationProperties的配置类来填充该bean，那么您可以创建一个简单的配置类测试：

@ConfigurationProperties("app")
public class ConfigProps {
    private int meaningOfLife;

    public int getMeaningOfLife() { return meaningOfLife; }
    public void setMeaningOfLife(int meaning) { this.meaningOfLife = meaning; }
}

class ConfigPropsTest {

    private final ApplicationContextRunner runner = new ApplicationContextRunner();

    @EnableConfigurationProperties(ConfigProps.class)
    static class TrivialConfiguration {
    }

    @Test
    void test() {
        runner.withUserConfiguration(TrivialConfiguration.class)
            .withPropertyValues("app.meaning-of-life=42")
            .run(context -> {
                assertEquals(42, context.getBean(ConfigProps.class).getMeaningOfLife());
            });
    }

}

将configuration传递给ApplicationContextRunner足以使其创建ConfigProps并使用可用属性填充它。