DsgQuery returns a Flow failed.

[hantsy]

In these days, I tried to update Dgs/Kotlin Coroutines example, when I updated the QueryTests.

And run it, and got the following exception.

Can't resolve value (/allPosts) : type mismatch error, expected type LIST got class kotlinx.coroutines.flow.FlowKt__BuildersKt$flowOf$$inlined$unsafeFlow$1

The query component is:

@DgsComponent
class PostsDataFetcher(val postService: PostService) {
    @DgsQuery
    fun allPosts(): Flow<Post> = postService.allPosts()
...
}

The testing codes is here, https://github.com/hantsy/spring-graphql-sample/blob/master/dgs-kotlin-co/src/test/kotlin/com/example/demo/QueryTests.kt

I got the similar errors when execute the allPosts in the /graphiql web interfaces.

{
  "errors": [
    {
      "message": "Can't resolve value (/allPosts) : type mismatch error, expected type LIST",
      "path": [
        "allPosts"
      ],
      "extensions": {
        "classification": "DataFetchingException"
      }
    }
  ],
  "data": null
}

[srinivasankavitha]

Currently we only support returning Mono and Flux for data fetchers.

[hantsy]

There is a issue add Kotlin Coroutines, #472