Add a utility function to get query responses to Decimal.

[puneet2019]

import {Tendermint34Client} from "@cosmjs/tendermint-rpc";
import {createProtobufRpcClient, QueryClient} from "@cosmjs/stargate";
import {QueryClientImpl as MintQueryClientImpl} from 'cosmjs-types/cosmos/mint/v1beta1/query';
import { Decimal } from "@cosmjs/math";

       const tendermintClient = await Tendermint34Client.connect("rpc.cosmos....");
       const queryClient = new QueryClient(tendermintClient);
       const rpcClient = createProtobufRpcClient(queryClient);
       const queryService = new MintQueryClientImpl(rpcClient);
       const response = await queryService.Inflation({});
       console.log(response.inflation)

Here response.infaltion returns a uint8array.

        let decoder = new TextDecoder('utf8');
        let decimalString = Decimal.fromAtomics(decoder.decode(response.inflation),18).toString()

Is there another way to do this?

[webmaster128]

Yeah, the proto encoding of Cosmos SDK decimals (github.com/cosmos/cosmos-sdk/types.Dec) is annoying.

Your code looks correct. decoder.decode(response.inflation) can be replaced with fromUtf8(response.inflation).

I was looking for an example how we do it in CosmJS but it seems like all the queries that return decimals are only implemented for Launchpad, not Stargate. I'd very much appreciate a port of packages/launchpad/src/lcdapi/mint.ts to packages/stargate/src/queries/.

[vishrutsingh]

@webmaster128 I'd like to take up the task. Thanks

[webmaster128]

What's really strange is the binary encoding in

// QueryInflationResponse is the response type for the Query/Inflation RPC
// method.
message QueryInflationResponse {
  // inflation is the current minting inflation value.
  bytes inflation = 1 [(gogoproto.customtype) = "github.com/cosmos/cosmos-sdk/types.Dec", (gogoproto.nullable) = false];
}

vs the string encoding in

// CommissionRates defines the initial commission rates to be used for creating
// a validator.
message CommissionRates {
  option (gogoproto.equal)            = true;
  option (gogoproto.goproto_stringer) = false;

  // rate is the commission rate charged to delegators, as a fraction.
  string rate = 1 [(gogoproto.customtype) = "github.com/cosmos/cosmos-sdk/types.Dec", (gogoproto.nullable) = false];
  // max_rate defines the maximum commission rate which validator can ever charge, as a fraction.
  string max_rate = 2 [
    (gogoproto.moretags)   = "yaml:\"max_rate\"",
    (gogoproto.customtype) = "github.com/cosmos/cosmos-sdk/types.Dec",
    (gogoproto.nullable)   = false
  ];
  // max_change_rate defines the maximum daily increase of the validator commission, as a fraction.
  string max_change_rate = 3 [
    (gogoproto.moretags)   = "yaml:\"max_change_rate\"",
    (gogoproto.customtype) = "github.com/cosmos/cosmos-sdk/types.Dec",
    (gogoproto.nullable)   = false
  ];
}

[webmaster128]

Could you have a look at #969 (new decodeCosmosSdkDecFromProto function) and see if that serves your needs?

[webmaster128]

#969 now conntains a full MintExtension for queries. Here I took the approch to wrap the whole protobuf API in custom types and do the decimal parsing internally. So it should be easy to use. It is somewhat inconsistent to many other query extensions that expose the original proto type. Happy for some 👀 on the PR.

[puneet2019]

Will check it out with @blackpanther1881

[webmaster128]

Please also note cosmos/cosmos-sdk#10863 if you care about the future of Decimals in Cosmos SDK.

[blackpanther1881]

@webmaster128 both decodeCosmosSdkDecFromProto and MintExtension from #969 working fine. decodeCosmosSdkDecFromProto response.toString() giving required result.