feat: Add gRPC query for remainder and account fractional balance (#1971

)

docs/core/proto-docs.md

@@ -481,6 +481,10 @@
     - [GenesisState](#kava.precisebank.v1.GenesisState)
 
 - [kava/precisebank/v1/query.proto](#kava/precisebank/v1/query.proto)
+    - [QueryFractionalBalanceRequest](#kava.precisebank.v1.QueryFractionalBalanceRequest)
+    - [QueryFractionalBalanceResponse](#kava.precisebank.v1.QueryFractionalBalanceResponse)
+    - [QueryRemainderRequest](#kava.precisebank.v1.QueryRemainderRequest)
+    - [QueryRemainderResponse](#kava.precisebank.v1.QueryRemainderResponse)
     - [QueryTotalFractionalBalancesRequest](#kava.precisebank.v1.QueryTotalFractionalBalancesRequest)
     - [QueryTotalFractionalBalancesResponse](#kava.precisebank.v1.QueryTotalFractionalBalancesResponse)
 
@@ -6689,6 +6693,61 @@ GenesisState defines the precisebank module's genesis state.
 
 
 
+<a name="kava.precisebank.v1.QueryFractionalBalanceRequest"></a>
+
+### QueryFractionalBalanceRequest
+QueryFractionalBalanceRequest defines the request type for Query/FractionalBalance method.
+
+
+| Field | Type | Label | Description |
+| ----- | ---- | ----- | ----------- |
+| `address` | [string](#string) |  | address is the account address to query fractional balance for. |
+
+
+
+
+
+
+<a name="kava.precisebank.v1.QueryFractionalBalanceResponse"></a>
+
+### QueryFractionalBalanceResponse
+QueryFractionalBalanceResponse defines the response type for Query/FractionalBalance method.
+
+
+| Field | Type | Label | Description |
+| ----- | ---- | ----- | ----------- |
+| `fractional_balance` | [cosmos.base.v1beta1.Coin](#cosmos.base.v1beta1.Coin) |  | fractional_balance is the fractional balance of the address. |
+
+
+
+
+
+
+<a name="kava.precisebank.v1.QueryRemainderRequest"></a>
+
+### QueryRemainderRequest
+QueryRemainderRequest defines the request type for Query/Remainder method.
+
+
+
+
+
+
+<a name="kava.precisebank.v1.QueryRemainderResponse"></a>
+
+### QueryRemainderResponse
+QueryRemainderResponse defines the response type for Query/Remainder method.
+
+
+| Field | Type | Label | Description |
+| ----- | ---- | ----- | ----------- |
+| `remainder` | [cosmos.base.v1beta1.Coin](#cosmos.base.v1beta1.Coin) |  | remainder is the amount backed by the reserve, but not yet owned by any account, i.e. not in circulation. |
+
+
+
+
+
+
 <a name="kava.precisebank.v1.QueryTotalFractionalBalancesRequest"></a>
 
 ### QueryTotalFractionalBalancesRequest
@@ -6728,6 +6787,8 @@ Query defines the gRPC querier service for precisebank module
 | Method Name | Request Type | Response Type | Description | HTTP Verb | Endpoint |
 | ----------- | ------------ | ------------- | ------------| ------- | -------- |
 | `TotalFractionalBalances` | [QueryTotalFractionalBalancesRequest](#kava.precisebank.v1.QueryTotalFractionalBalancesRequest) | [QueryTotalFractionalBalancesResponse](#kava.precisebank.v1.QueryTotalFractionalBalancesResponse) | TotalFractionalBalances returns the total sum of all fractional balances managed by the precisebank module. | GET|/kava/precisebank/v1/total_fractional_balances|
+| `Remainder` | [QueryRemainderRequest](#kava.precisebank.v1.QueryRemainderRequest) | [QueryRemainderResponse](#kava.precisebank.v1.QueryRemainderResponse) | Remainder returns the amount backed by the reserve, but not yet owned by any account, i.e. not in circulation. | GET|/kava/precisebank/v1/remainder|
+| `FractionalBalance` | [QueryFractionalBalanceRequest](#kava.precisebank.v1.QueryFractionalBalanceRequest) | [QueryFractionalBalanceResponse](#kava.precisebank.v1.QueryFractionalBalanceResponse) | FractionalBalance returns only the fractional balance of an address. This does not include any integer balance. | GET|/kava/precisebank/v1/fractional_balance/{address}|
 
  <!-- end services -->
 

proto/kava/precisebank/v1/query.proto

@@ -15,6 +15,18 @@ service Query {
   rpc TotalFractionalBalances(QueryTotalFractionalBalancesRequest) returns (QueryTotalFractionalBalancesResponse) {
     option (google.api.http).get = "/kava/precisebank/v1/total_fractional_balances";
   }
+
+  // Remainder returns the amount backed by the reserve, but not yet owned by
+  // any account, i.e. not in circulation.
+  rpc Remainder(QueryRemainderRequest) returns (QueryRemainderResponse) {
+    option (google.api.http).get = "/kava/precisebank/v1/remainder";
+  }
+
+  // FractionalBalance returns only the fractional balance of an address. This
+  // does not include any integer balance.
+  rpc FractionalBalance(QueryFractionalBalanceRequest) returns (QueryFractionalBalanceResponse) {
+    option (google.api.http).get = "/kava/precisebank/v1/fractional_balance/{address}";
+  }
 }
 
 // QueryTotalFractionalBalancesRequest defines the request type for Query/TotalFractionalBalances method.
@@ -26,3 +38,25 @@ message QueryTotalFractionalBalancesResponse {
   // module.
   cosmos.base.v1beta1.Coin total = 1 [(gogoproto.nullable) = false];
 }
+
+// QueryRemainderRequest defines the request type for Query/Remainder method.
+message QueryRemainderRequest {}
+
+// QueryRemainderResponse defines the response type for Query/Remainder method.
+message QueryRemainderResponse {
+  // remainder is the amount backed by the reserve, but not yet owned by any
+  // account, i.e. not in circulation.
+  cosmos.base.v1beta1.Coin remainder = 1 [(gogoproto.nullable) = false];
+}
+
+// QueryFractionalBalanceRequest defines the request type for Query/FractionalBalance method.
+message QueryFractionalBalanceRequest {
+  // address is the account address to query  fractional balance for.
+  string address = 1;
+}
+
+// QueryFractionalBalanceResponse defines the response type for Query/FractionalBalance method.
+message QueryFractionalBalanceResponse {
+  // fractional_balance is the fractional balance of the address.
+  cosmos.base.v1beta1.Coin fractional_balance = 1 [(gogoproto.nullable) = false];
+}

x/precisebank/keeper/grpc_query.go

@@ -36,3 +36,38 @@ func (s queryServer) TotalFractionalBalances(
 		Total: totalCoin,
 	}, nil
 }
+
+// Remainder returns the remainder amount in x/precisebank.
+func (s queryServer) Remainder(
+	goCtx context.Context,
+	req *types.QueryRemainderRequest,
+) (*types.QueryRemainderResponse, error) {
+	ctx := sdk.UnwrapSDKContext(goCtx)
+
+	remainder := s.keeper.GetRemainderAmount(ctx)
+	remainderCoin := sdk.NewCoin(types.ExtendedCoinDenom, remainder)
+
+	return &types.QueryRemainderResponse{
+		Remainder: remainderCoin,
+	}, nil
+}
+
+// FractionalBalance returns the fractional balance of an account.
+func (s queryServer) FractionalBalance(
+	goCtx context.Context,
+	req *types.QueryFractionalBalanceRequest,
+) (*types.QueryFractionalBalanceResponse, error) {
+	ctx := sdk.UnwrapSDKContext(goCtx)
+
+	address, err := sdk.AccAddressFromBech32(req.Address)
+	if err != nil {
+		return nil, err
+	}
+
+	amt := s.keeper.GetFractionalBalance(ctx, address)
+	fractionalBalance := sdk.NewCoin(types.ExtendedCoinDenom, amt)
+
+	return &types.QueryFractionalBalanceResponse{
+		FractionalBalance: fractionalBalance,
+	}, nil
+}

x/precisebank/keeper/grpc_query_test.go

@@ -8,6 +8,7 @@ import (
 	sdkmath "cosmossdk.io/math"
 	"github.com/cosmos/cosmos-sdk/baseapp"
 	sdk "github.com/cosmos/cosmos-sdk/types"
+	minttypes "github.com/cosmos/cosmos-sdk/x/mint/types"
 	"github.com/stretchr/testify/suite"
 
 	"github.com/kava-labs/kava/x/precisebank/keeper"
@@ -84,3 +85,87 @@ func (suite *grpcQueryTestSuite) TestQueryTotalFractionalBalance() {
 		})
 	}
 }
+
+func (suite *grpcQueryTestSuite) TestQueryRemainder() {
+	res, err := suite.queryClient.Remainder(
+		context.Background(),
+		&types.QueryRemainderRequest{},
+	)
+	suite.Require().NoError(err)
+
+	expRemainder := sdk.NewCoin(types.ExtendedCoinDenom, sdkmath.ZeroInt())
+	suite.Require().Equal(expRemainder, res.Remainder)
+
+	// Mint fractional coins to create non-zero remainder
+
+	pbk := suite.App.GetPrecisebankKeeper()
+
+	coin := sdk.NewCoin(types.ExtendedCoinDenom, sdkmath.OneInt())
+	err = pbk.MintCoins(
+		suite.Ctx,
+		minttypes.ModuleName,
+		sdk.NewCoins(coin),
+	)
+	suite.Require().NoError(err)
+
+	res, err = suite.queryClient.Remainder(
+		context.Background(),
+		&types.QueryRemainderRequest{},
+	)
+	suite.Require().NoError(err)
+
+	expRemainder.Amount = types.ConversionFactor().Sub(coin.Amount)
+	suite.Require().Equal(expRemainder, res.Remainder)
+}
+
+func (suite *grpcQueryTestSuite) TestQueryFractionalBalance() {
+	testCases := []struct {
+		name        string
+		giveBalance sdkmath.Int
+	}{
+		{
+			"zero",
+			sdkmath.ZeroInt(),
+		},
+		{
+			"min amount",
+			sdkmath.OneInt(),
+		},
+		{
+			"max amount",
+			types.ConversionFactor().SubRaw(1),
+		},
+		{
+			"multiple integer amounts, 0 fractional",
+			types.ConversionFactor().MulRaw(5),
+		},
+		{
+			"multiple integer amounts, non-zero fractional",
+			types.ConversionFactor().MulRaw(5).Add(types.ConversionFactor().QuoRaw(2)),
+		},
+	}
+
+	for _, tc := range testCases {
+		suite.Run(tc.name, func() {
+			suite.SetupTest()
+
+			addr := sdk.AccAddress([]byte("test"))
+
+			coin := sdk.NewCoin(types.ExtendedCoinDenom, tc.giveBalance)
+			suite.MintToAccount(addr, sdk.NewCoins(coin))
+
+			res, err := suite.queryClient.FractionalBalance(
+				context.Background(),
+				&types.QueryFractionalBalanceRequest{
+					Address: addr.String(),
+				},
+			)
+			suite.Require().NoError(err)
+
+			// Only fractional amount, even if minted more than conversion factor
+			expAmount := tc.giveBalance.Mod(types.ConversionFactor())
+			expFractionalBalance := sdk.NewCoin(types.ExtendedCoinDenom, expAmount)
+			suite.Require().Equal(expFractionalBalance, res.FractionalBalance)
+		})
+	}
+}