Subscription test is blocked

[hantsy]

In my example project, I used a Flow to expose subscriptions endpoints.

@Component
class Subscriptions(val postService: PostService) : Subscription {

    fun commentAdded(): Flow<Comment> {
        return postService.commentAdded()
    }
}

The Flow is a MutableSharedFlow(replay=1), when a mutation addComment is executed, flow.emit(comment) will be called.

But I followed the examples to create tests to verify the subscriptions, when the subscriptions is connected, it will be blocked and never quit.

// the code fragments to verify subscriptions.
 // add comments  to post
        val commentQuery =
            "mutation addComment(\$input: CommentInput!) { addComment(input:\$input) { id postId content}}"
        val comment1Variables = mapOf(
            "input" to mapOf(
                "postId" to postId,
                "content" to "comment1"
            )
        )
        val comment2Variables = mapOf(
            "input" to mapOf(
                "postId" to postId,
                "content" to "comment2"
            )
        )

        val addComment1Response = client.post()
            .bodyValue(mapOf("query" to commentQuery, "variables" to comment1Variables))
            .awaitExchange<Map<String, Map<String, Map<String, Any>>>> {
                it.statusCode() shouldBe HttpStatus.OK
                it.awaitBody()
            }

        val addComment1Data = addComment1Response["data"]
        (addComment1Data!!["addComment"]!!["content"] as String) shouldBe "comment1"

        val addComment2Response = client.post()
            .bodyValue(mapOf("query" to commentQuery, "variables" to comment2Variables))
            .awaitExchange<Map<String, Map<String, Map<String, Any>>>> {
                it.statusCode() shouldBe HttpStatus.OK
                it.awaitBody()
            }

        val addComment2Data = addComment2Response["data"]
        (addComment2Data!!["addComment"]!!["content"] as String) shouldBe "comment2"

        // subscribe to event `commentAdded`
        val query = "subscription onCommentAdded { commentAdded { id content } }"
        val output = TestPublisher.create<String>()

       val subscription = socketClient.execute(uri) { session -> executeSubscription(session, query, output) }
            .subscribe()

        StepVerifier.create(output)
            .consumeNextWith { it shouldContain "\"content\":\"comment2\"" }
            .expectComplete()
            .verify()

        subscription.dispose()
    }

The whole subscription tests codes is here: https://github.com/hantsy/spring-graphql-sample/blob/master/graphql-kotlin/src/test/kotlin/com/example/demo/DemoApplicationTests.kt#L87-L192

[hantsy]

Still encountered this issue, I am using the following codes to serve a subscription.

override suspend fun addComment(commentInput: CommentInput): Comment {
      // save the comment info
      flow.emit(comment)
      return comment
  }

  val flow = MutableSharedFlow<Comment>(replay = 1)

  // subscription: commentAdded
  override fun commentAdded(): Flow<Comment> = flow.asSharedFlow()

[milgner]

I had a very similar issue when the GraphQL server did not react to the connection_init and did not send out a corresponding ack. It's probably hard to see what messages are being exchanged on the lower levels from within the test framework - but maybe you can run a Wireshark capture to see what messages are being exchanged on the websocket?

[hantsy]

I have updated to the latest 7.0.2, and keep using the legacy SUBSCRIPTION_TRANSPORT_WS protocol, and add log into the client session.receive block and got the keep alive messages from server side, and it never quit.

2023-11-05T23:24:26.104+08:00 DEBUG 10908 --- [ctor-http-nio-4] com.example.demo.DemoApplicationTests    : received message:ApolloSubscriptionOperationMessage(type=ka, id=null, payload=null)
2023-11-05T23:24:27.099+08:00 DEBUG 10908 --- [ctor-http-nio-4] com.example.demo.DemoApplicationTests    : received message:ApolloSubscriptionOperationMessage(type=ka, id=null, payload=null)
2023-11-05T23:24:28.090+08:00 DEBUG 10908 --- [ctor-http-nio-4] com.example.demo.DemoApplicationTests    : received message:ApolloSubscriptionOperationMessage(type=ka, id=null, payload=null)