Is there a workaround for this issue? <https://you...

# announcements

[nglauber]

Is there a workaround for this issue?
https://youtrack.jetbrains.com/issue/KT-34051

[Youssef Shoaib [MOD]]

What's the code that's causing this error? Because I fiddled around with this a bit and I think I could possibly find a workaround depending on your specific case.

[nglauber]

this is my sequence of calls…

class CitySfRepository : BaseSfRepository() {
    override suspend fun cityById(id: Int): City? =
            getObject( "SELECT Id, ID__c, Name FROM $objectType WHERE ID__c = $id")
}

This getObject function is defined in the parent class BaseSfRepository

protected suspend inline fun <reified T> getObject(q: String): T? =
        suspendCoroutine { continuation ->
            sendAsync<List<T>?>(
                    RestRequest.getRequestForQuery(
                            ApiVersionStrings.VERSION_NUMBER,
                            q
                    ),
                    { list ->
                        continuation.resume(list?.first())
                    },
                    { exception ->
                        continuation.resumeWithException(exception)
                    }
            )
        }

In this sendAsync function I’m getting the response and parsing using Gson library

protected inline fun <reified T> parseResponse(
            restResponse: RestResponse
    ): T? {
        val x = gson.fromJson<T?>(
                restResponse.asJSONObject().getJSONArray("records").toString(),
                object : TypeToken<T?>() {}.type
        )
        return x
    }

I’m getting this error:

java.lang.ClassCastException: com.google.gson.internal.LinkedTreeMap cannot be cast to com.test.mycompany.City

[Youssef Shoaib [MOD]]

This looks like an entirely different error I think. What line are you getting the cast exception on?

[nglauber]

Looks like that the compiler misses the type T when I call sendAsync<List<T>?>. Because the Gson is returning a list of List<LinkedTreeMap> when it parses the JSON

[nglauber]

The interesting part is: this function works… 🤷‍♂️

// From CitySfRepository
    override suspend fun allCities(): List<City> =
            getObjectList("SELECT Id, ID__c, Name FROM $objectType ORDER BY Name") ?: emptyList()

[nglauber]

And getObjectList passes the T directly…

protected suspend inline fun <reified T> getObjectList(q: String): T? =
            suspendCoroutine { continuation ->
                sendAsync<T?>(
                        RestRequest.getRequestForQuery(
                                ApiVersionStrings.VERSION_NUMBER,
                                q
                        ),
                        { list ->
                            continuation.resume(list)
                        },
                        { exception ->
                            continuation.resumeWithException(exception)
                        }
                )
            }

[nglauber]

[FIXED] I was answering my own question 🤦‍♂️
the list type is erased, so I reified it 😉

protected suspend inline fun <reified T, reified J: List<T>> getObject(q: String): T? =
            suspendCoroutine { continuation ->
                sendAsync<J?>(
                        RestRequest.getRequestForQuery(
                                ApiVersionStrings.VERSION_NUMBER,
                                q
                        ),
                        { list ->
                            continuation.resume(list?.first())
                        },
                        { exception ->
                            continuation.resumeWithException(exception)
                        }
                )
            }

[Youssef Shoaib [MOD]]

lol happens to the best of us. Nice job!