Hi Team, We are trying to add unit test for subsc...

# apollo-kotlin

[Monika Singh]

Hi Team,

We are trying to add unit test for subscriptions, but getting below exception: java.net.ProtocolException: Expected 'Connection' header value 'Upgrade' but was 'close'

Could someone please help regarding how to test GQL subscriptions?

Stacktrace:


java.net.ProtocolException: Expected 'Connection' header value 'Upgrade' but was 'close'
	at _COROUTINE._BOUNDARY._(CoroutineDebugging.kt:46)
	at kotlinx.coroutines.channels.BufferedChannel.receive$suspendImpl(BufferedChannel.kt:681)
	at kotlinx.coroutines.channels.BufferedChannel.receive(BufferedChannel.kt)
	at com.apollographql.apollo3.internal.ChannelWrapper.receive(ChannelWrapper.kt)
	at com.apollographql.apollo3.network.ws.DefaultWebSocketEngine$open$3.receive(OkHttpWebSocketEngine.kt:86)
	at com.apollographql.apollo3.network.ws.WsProtocol.receiveMessageMap(WsProtocol.kt:131)
	at com.apollographql.apollo3.network.ws.SubscriptionWsProtocol$connectionInit$2.invokeSuspend(SubscriptionWsProtocol.kt:39)
	at com.apollographql.apollo3.network.ws.SubscriptionWsProtocol$connectionInit$2.invoke(SubscriptionWsProtocol.kt)
	at com.apollographql.apollo3.network.ws.SubscriptionWsProtocol$connectionInit$2.invoke(SubscriptionWsProtocol.kt)
	at kotlinx.coroutines.intrinsics.UndispatchedKt.startUndispatchedOrReturnIgnoreTimeout(Undispatched.kt:89)
	at kotlinx.coroutines.TimeoutKt.setupTimeout(Timeout.kt:151)
	at kotlinx.coroutines.TimeoutKt.withTimeout(Timeout.kt:46)
	at com.apollographql.apollo3.network.ws.SubscriptionWsProtocol.connectionInit(SubscriptionWsProtocol.kt:38)
	at com.apollographql.apollo3.network.ws.WebSocketNetworkTransport.supervise(WebSocketNetworkTransport.kt:214)
	at com.apollographql.apollo3.network.ws.WebSocketNetworkTransport.access$supervise(WebSocketNetworkTransport.kt:61)
	at com.apollographql.apollo3.network.ws.WebSocketNetworkTransport$supervise$1.invokeSuspend(WebSocketNetworkTransport.kt)
	at com.apollographql.apollo3.network.ws.SubscriptionWsProtocol.connectionInit(SubscriptionWsProtocol.kt:38)
	at com.apollographql.apollo3.network.ws.WebSocketNetworkTransport.supervise(WebSocketNetworkTransport.kt:214)
	at com.apollographql.apollo3.network.ws.WebSocketNetworkTransport$1.invokeSuspend(WebSocketNetworkTransport.kt:98)
Caused by: java.net.ProtocolException: Expected 'Connection' header value 'Upgrade' but was 'close'
	at okhttp3.internal.ws.RealWebSocket.checkUpgradeSuccess$okhttp(RealWebSocket.kt:230)
	at okhttp3.internal.ws.RealWebSocket$connect$1.onResponse(RealWebSocket.kt:170)
	at okhttp3.internal.connection.RealCall$AsyncCall.run(RealCall.kt:519)
	at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
	at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
	at java.base/java.lang.Thread.run(Unknown Source)

Subscription:

val client = ApolloClient.Builder()
client.subscriptionNetworkTransport(
    WebSocketNetworkTransport.Builder()
        .protocol(
            SubscriptionWsProtocol.Factory(connectionPayload = {
                mapOf(
                    "token" to ""
                )
            })
        )
        .serverUrl(serverUrl = endpoint)
        .build()
)

public val mockGQLServer: MockServer by lazy { MockServer() }

@Test
fun testSubscribe() = testScope {
    mockGQLServer.enqueue(gqlMockResponse(responseString = "", httpStatusCode = 101))
    val resultFlow = client.subscription(subscription).toFlow()
    resultFlow.test {
        val result = awaitItem()
        awaitComplete()
    }
}

private fun gqlMockResponse(responseString: String, httpStatusCode: Int = 200): MockResponse {
    val headers = mapOf(
        "Accept" to "application/json",
        "Content-Type" to "application/json",
        "Connection" to "Upgrade",
        "Upgrade" to "websocket"
    )
    return MockResponse.Builder()
        .body(responseString)
        .statusCode(httpStatusCode)
        .headers(
            headers
        ).build()
}

[mbonnin]

Testing WebSockets is not easy. You’ll need the 4.0.0 betas if you’re using apollo-mockserver for WebSocket support.

[mbonnin]

You can take a look at this integration test for an example

[mbonnin]

In particular, you’ll want mockServer.enqueueWebSocket() instead of just enqueue()

[mbonnin]

Also note that those APIs are mainly used internally for Apollo Kotlin integration tests. While they are publicly available, they are a lot more unstable compared to the usual ApolloClient , etc.. APIs

[mbonnin]

Another option is to build your own server using Ktor or something similar

[Monika Singh]

Thanks @mbonnin 👍