initPayload from SocketClientConfig is not accepting Json-like data

Question

Describe the bug

I'm getting the following error message

The argument type 'Map<String, Map<String,String>>' can't be assigned to the parameter type 'Future<dynamic> Function()'.

for initPayload parameter at this code:

static final WebSocketLink webSocketLink = WebSocketLink(
    url: 'wss://hasura.io/learn/graphql',
    config: SocketClientConfig(
      autoReconnect: true,
      inactivityTimeout: Duration(seconds: 30),
      initPayload: {'headers': {'Authorization': _token}},
    ),
  );

To Reproduce

• Following the GraphQL Flutter Tutorial.
• According to initPayload property help: Can be null, but must be a valid json structure if provided.
• According to GetInitPayload typedef help: typedef GetInitPayload = FutureOr<dynamic> Function();

Answer 1

The answer can be found at this post.