如何将自定义bean全局添加到spring启动测试上下文中

Question

我在spring boot应用程序中实现了firebase消息传递。为此，我创建了一个类似本文所述的bean，以便轻松访问FirebaseMessaging实例。然后，该bean被注入到服务中。然后，当调用利用FirebaseMessagingbean的服务方法时，所述服务被注入到我的控制器中。

现在我的问题是该项目的测试套件（使用JUnit5

MyControllerTest > testFunction() FAILED
    java.lang.IllegalStateException at DefaultCacheAwareContextLoaderDelegate.java:132
        Caused by: org.springframework.beans.factory.UnsatisfiedDependencyException at ConstructorResolver.java:800
            Caused by: org.springframework.beans.factory.BeanCreationException at ConstructorResolver.java:658
        Caused by: org.springframework.beans.factory.UnsatisfiedDependencyException at ConstructorResolver.java:800
                Caused by: org.springframework.beans.BeanInstantiationException at SimpleInstantiationStrategy.java:185
            Caused by: org.springframework.beans.factory.BeanCreationException at ConstructorResolver.java:658
                Caused by: org.springframework.beans.BeanInstantiationException at SimpleInstantiationStrategy.java:185
                    Caused by: java.lang.IllegalStateException at Preconditions.java:513
                    Caused by: java.lang.IllegalStateException at Preconditions.java:513

根本原因：

Caused by: java.lang.IllegalStateException: FirebaseApp name my-app already exists!
    at com.google.common.base.Preconditions.checkState(Preconditions.java:513)
    at com.google.firebase.FirebaseApp.initializeApp(FirebaseApp.java:222)
    at com.google.firebase.FirebaseApp.initializeApp(FirebaseApp.java:215)
    at my.example.app.firebase.FirebaseMessagingBean.firebaseMessaging(FirebaseMessagingBean.kt:25)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:78)
    at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.base/java.lang.reflect.Method.invoke(Method.java:567)
    at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:154)
    ... 125 more

注意：这些错误只有在整体运行testsuite时才会出现。如果我自己运行一个测试类，则不会出现错误。

解决这个问题的一种方法是向每个类添加一个@MockBean，这样测试上下文就会加载bean。因此，我可以继续并简单地将其添加到每个测试类中，但我更希望使用一种方法，将FirebaseMessaging@MockBean自动注入到每个测试类中。每当开发人员忘记将@MockBean添加到他的测试类中时，测试套件不会失败。

实现这一目标的正确方法是什么？

（这段代码是静态编程语言，但我也很乐意接受解决方案的java代码。）

代码：

@Component
class FirebaseMessagingBean {
    @Bean
    fun firebaseMessaging(): FirebaseMessaging {
        val privateKeyFileURL = ClassLoader.getSystemResource("firebase-cloud-messaging.json")
            ?: throw IOException("Couldn't read firebase credentials")
        val privateKeyStream = File(privateKeyFileURL.file).inputStream()
        val googleCredentials = GoogleCredentials.fromStream(privateKeyStream)
        val firebaseOptions = FirebaseOptions.builder().setCredentials(googleCredentials)
            .build()
        val app = FirebaseApp.initializeApp(firebaseOptions, "my-app")
        return FirebaseMessaging.getInstance(app)
    }
}

@Service
class FirebaseNotificationService(
    val firebaseMessaging: FirebaseMessaging
) {
    fun sendNotification(msg: String) { /* ... */ }
}

@RestController
@RequestMapping("/api/route")
class MyController(
    val firebaseNotificationService: FirebaseNotificationService,
) {
    @PostMapping()
    fun postRoute(): ResponseEntity<Any> {
        firebaseNotificationService.sendNotification("msg")
        // ...
    }
}

测试类示例

@AutoConfigureMockMvc
@SpringBootTest
class DeviceControllerTest {
    // injections
    
    @Test
    fun testFunction() { /* ... */ }
}

Answer 1

我只在之前没有实例化的情况下初始化FirebasApp实例，从而修复了这个问题。

更新的bean：

class FirebaseMessagingBean {
    @Bean
    fun firebaseMessaging(): FirebaseMessaging {
        val privateKeyFileURL = ClassLoader.getSystemResource("firebase-cloud-messaging.json")
            ?: throw IOException("Couldn't read firebase credentials")
        val privateKeyStream = File(privateKeyFileURL.file).inputStream()
        val googleCredentials = GoogleCredentials.fromStream(privateKeyStream)
        val firebaseOptions = FirebaseOptions
            .builder()
            .setCredentials(googleCredentials)
            .build()
        val app = try {
            FirebaseApp.getInstance()
        } catch (iae: IllegalStateException) {
            FirebaseApp.initializeApp(firebaseOptions)
        }
        return FirebaseMessaging.getInstance(app)
    }
}