Account Balance Tracking

[ejfitzgerald]

Acceptance Criteria

To add the ability for a user to query a specific address account balance. For the first version of this task only native balances should be captured.

Below is an illustrative schema for the problem

type NativeBalance {
  amount: BigInt!
  denom: String!
}

type Account @entity {
  address: ID! # might be also String!
  nativeBalances: [NativeBalance!]!
}

Potential strategy

Create updateNativeBalance function:

1. Function queries database for existing instances of 'Account' with the relevant native transfer address
2. If no existing entity returned, create new one
3. Update the balance of the 'Account'
4. Insert this function to all cases where balances may change in handlers for coin_spent and coin_received events
5. Iterate to increase coverage of balance changes

Blocked on

• Process genesis for initial state #79 - Process genesis for initial state

[bryanchriswhite]

I think we might be able to listen for the coin_spent and coin_received events from the bank module for this.

I did some brief querying to see what kinds of messages correspond to these events and there seems to be a variety. Here's the query I used:

query coinReceivedEvents {
  events(
    first: 10
    filter: {
      type: { equalTo: "coin_received" }
      transaction: {
        messages: {
          some: {
            typeUrl: {
              notIn: [
                "/cosmos.bank.v1beta1.MsgSend"
                "/cosmos.bank.v1beta1.MsgMultiSend"
              ]
            }
          }
        }
      }
    }
  ) {
    nodes {
      #id
      type
      #attributes
      transaction {
        messages {
          nodes {
            typeUrl
            json
          }
        }
      }
    }
  }
}

query coinSpentEvents {
  events(
    first: 10
    filter: {
      type: { equalTo: "coin_spent" }
      transaction: {
        messages: {
          some: {
            typeUrl: {
              notIn: [
                "/cosmos.bank.v1beta1.MsgSend"
                "/cosmos.bank.v1beta1.MsgMultiSend"
              ]
            }
          }
        }
      }
    }
  ) {
    nodes {
      #id
      type
      #attributes
      transaction {
        messages {
          nodes {
            typeUrl
            json
          }
        }
      }
    }
  }
}

[bryanchriswhite]

I think we will need to process the genesis for the respective network to get the starting point which we can use together with the accumulated offset to calculate current balances.