feat: add support for spendable balances gRPC query

CHANGELOG.md

@@ -39,6 +39,7 @@ Ref: https://keepachangelog.com/en/1.0.0/
 
 ### Features
 
+* (x/bank) [\#11417](https://github.com/cosmos/cosmos-sdk/pull/11417) Introduce a new `SpendableBalances` gRPC query that retrieves an account's total (paginated) spendable balances.
 * [\#11441](https://github.com/cosmos/cosmos-sdk/pull/11441) Added a new method, `IsLTE`, for `types.Coin`. This method is used to check if a `types.Coin` is less than or equal to another `types.Coin`.
 * (x/upgrade) [\#11116](https://github.com/cosmos/cosmos-sdk/pull/11116) `MsgSoftwareUpgrade` and has been added to support v1beta2 msgs-based gov proposals.
 * [\#11308](https://github.com/cosmos/cosmos-sdk/pull/11308) Added a mandatory metadata field to Vote in x/gov v1beta2.

proto/cosmos/bank/v1beta1/query.proto

@@ -22,6 +22,12 @@ service Query {
     option (google.api.http).get = "/cosmos/bank/v1beta1/balances/{address}";
   }
 
+  // SpendableBalances queries the spenable balance of all coins for a single
+  // account.
+  rpc SpendableBalances(QuerySpendableBalancesRequest) returns (QuerySpendableBalancesResponse) {
+    option (google.api.http).get = "/cosmos/bank/v1beta1/spendable_balances/{address}";
+  }
+
   // TotalSupply queries the total supply of all coins.
   rpc TotalSupply(QueryTotalSupplyRequest) returns (QueryTotalSupplyResponse) {
     option (google.api.http).get = "/cosmos/bank/v1beta1/supply";
@@ -96,6 +102,30 @@ message QueryAllBalancesResponse {
   cosmos.base.query.v1beta1.PageResponse pagination = 2;
 }
 
+// QuerySpendableBalancesRequest defines the gRPC request structure for querying
+// an account's spendable balances.
+message QuerySpendableBalancesRequest {
+  option (gogoproto.equal)           = false;
+  option (gogoproto.goproto_getters) = false;
+
+  // address is the address to query spendable balances for.
+  string address = 1 [(cosmos_proto.scalar) = "cosmos.AddressString"];
+
+  // pagination defines an optional pagination for the request.
+  cosmos.base.query.v1beta1.PageRequest pagination = 2;
+}
+
+// QuerySpendableBalancesResponse defines the gRPC response structure for querying
+// an account's spendable balances.
+message QuerySpendableBalancesResponse {
+  // balances is the spendable balances of all the coins.
+  repeated cosmos.base.v1beta1.Coin balances = 1
+      [(gogoproto.nullable) = false, (gogoproto.castrepeated) = "github.com/cosmos/cosmos-sdk/types.Coins"];
+
+  // pagination defines the pagination in the response.
+  cosmos.base.query.v1beta1.PageResponse pagination = 2;
+}
+
 // QueryTotalSupplyRequest is the request type for the Query/TotalSupply RPC
 // method.
 message QueryTotalSupplyRequest {

x/bank/keeper/grpc_query.go

@@ -75,6 +75,42 @@ func (k BaseKeeper) AllBalances(ctx context.Context, req *types.QueryAllBalances
 	return &types.QueryAllBalancesResponse{Balances: balances, Pagination: pageRes}, nil
 }
 
+// SpendableBalances implements a gRPC query handler for retrieving an account's
+// spendable balances.
+func (k BaseKeeper) SpendableBalances(ctx context.Context, req *types.QuerySpendableBalancesRequest) (*types.QuerySpendableBalancesResponse, error) {
+	if req == nil {
+		return nil, status.Error(codes.InvalidArgument, "empty request")
+	}
+
+	addr, err := sdk.AccAddressFromBech32(req.Address)
+	if err != nil {
+		return nil, status.Errorf(codes.InvalidArgument, "invalid address: %s", err.Error())
+	}
+
+	sdkCtx := sdk.UnwrapSDKContext(ctx)
+
+	balances := sdk.NewCoins()
+	accountStore := k.getAccountStore(sdkCtx, addr)
+	zeroAmt := sdk.ZeroInt()
+
+	pageRes, err := query.Paginate(accountStore, req.Pagination, func(key, value []byte) error {
+		balances = append(balances, sdk.NewCoin(string(key), zeroAmt))
+		return nil
+	})
+	if err != nil {
+		return nil, status.Errorf(codes.InvalidArgument, "paginate: %v", err)
+	}
+
+	result := sdk.NewCoins()
+	spendable := k.SpendableCoins(sdkCtx, addr)
+
+	for _, c := range balances {
+		result = append(result, sdk.NewCoin(c.Denom, spendable.AmountOf(c.Denom)))
+	}
+
+	return &types.QuerySpendableBalancesResponse{Balances: result, Pagination: pageRes}, nil
+}
+
 // TotalSupply implements the Query/TotalSupply gRPC method
 func (k BaseKeeper) TotalSupply(ctx context.Context, req *types.QueryTotalSupplyRequest) (*types.QueryTotalSupplyResponse, error) {
 	sdkCtx := sdk.UnwrapSDKContext(ctx)

x/bank/keeper/grpc_query_test.go

@@ -3,11 +3,14 @@ package keeper_test
 import (
 	gocontext "context"
 	"fmt"
+	"time"
 
+	"github.com/cosmos/cosmos-sdk/baseapp"
 	"github.com/cosmos/cosmos-sdk/testutil/testdata"
 	sdk "github.com/cosmos/cosmos-sdk/types"
 	"github.com/cosmos/cosmos-sdk/types/query"
 	authtypes "github.com/cosmos/cosmos-sdk/x/auth/types"
+	vestingtypes "github.com/cosmos/cosmos-sdk/x/auth/vesting/types"
 	"github.com/cosmos/cosmos-sdk/x/bank/testutil"
 	"github.com/cosmos/cosmos-sdk/x/bank/types"
 	minttypes "github.com/cosmos/cosmos-sdk/x/mint/types"
@@ -86,6 +89,56 @@ func (suite *IntegrationTestSuite) TestQueryAllBalances() {
 	suite.Nil(res.Pagination.NextKey)
 }
 
+func (suite *IntegrationTestSuite) TestSpendableBalances() {
+	app, ctx, queryClient := suite.app, suite.ctx, suite.queryClient
+	_, _, addr := testdata.KeyTestPubAddr()
+	ctx = ctx.WithBlockTime(time.Now())
+
+	_, err := queryClient.SpendableBalances(sdk.WrapSDKContext(ctx), &types.QuerySpendableBalancesRequest{})
+	suite.Require().Error(err)
+
+	pageReq := &query.PageRequest{
+		Key:        nil,
+		Limit:      2,
+		CountTotal: false,
+	}
+	req := types.NewQuerySpendableBalancesRequest(addr, pageReq)
+
+	res, err := queryClient.SpendableBalances(sdk.WrapSDKContext(ctx), req)
+	suite.Require().NoError(err)
+	suite.Require().NotNil(res)
+	suite.True(res.Balances.IsZero())
+
+	fooCoins := newFooCoin(50)
+	barCoins := newBarCoin(30)
+
+	origCoins := sdk.NewCoins(fooCoins, barCoins)
+	acc := app.AccountKeeper.NewAccountWithAddress(ctx, addr)
+	acc = vestingtypes.NewContinuousVestingAccount(
+		acc.(*authtypes.BaseAccount),
+		sdk.NewCoins(fooCoins),
+		ctx.BlockTime().Unix(),
+		ctx.BlockTime().Add(time.Hour).Unix(),
+	)
+
+	app.AccountKeeper.SetAccount(ctx, acc)
+	suite.Require().NoError(testutil.FundAccount(app.BankKeeper, ctx, acc.GetAddress(), origCoins))
+
+	// move time forward for some tokens to vest
+	ctx = ctx.WithBlockTime(ctx.BlockTime().Add(30 * time.Minute))
+	queryHelper := baseapp.NewQueryServerTestHelper(ctx, app.InterfaceRegistry())
+	types.RegisterQueryServer(queryHelper, app.BankKeeper)
+	queryClient = types.NewQueryClient(queryHelper)
+
+	res, err = queryClient.SpendableBalances(sdk.WrapSDKContext(ctx), req)
+	suite.Require().NoError(err)
+	suite.Require().NotNil(res)
+	suite.Equal(2, res.Balances.Len())
+	suite.Nil(res.Pagination.NextKey)
+	suite.EqualValues(30, res.Balances[0].Amount.Int64())
+	suite.EqualValues(25, res.Balances[1].Amount.Int64())
+}
+
 func (suite *IntegrationTestSuite) TestQueryTotalSupply() {
 	app, ctx, queryClient := suite.app, suite.ctx, suite.queryClient
 	res, err := queryClient.TotalSupply(gocontext.Background(), &types.QueryTotalSupplyRequest{})

x/bank/keeper/keeper_test.go

@@ -95,7 +95,7 @@ func (suite *IntegrationTestSuite) initKeepersWithmAccPerms(blockedAddrs map[str
 
 func (suite *IntegrationTestSuite) SetupTest() {
 	app := simapp.Setup(suite.T(), false)
-	ctx := app.BaseApp.NewContext(false, tmproto.Header{})
+	ctx := app.BaseApp.NewContext(false, tmproto.Header{Time: time.Now()})
 
 	app.AccountKeeper.SetParams(ctx, authtypes.DefaultParams())
 	app.BankKeeper.SetParams(ctx, types.DefaultParams())

x/bank/types/querier.go

@@ -25,6 +25,13 @@ func NewQueryAllBalancesRequest(addr sdk.AccAddress, req *query.PageRequest) *Qu
 	return &QueryAllBalancesRequest{Address: addr.String(), Pagination: req}
 }
 
+// NewQuerySpendableBalancesRequest creates a new instance of a
+// QuerySpendableBalancesRequest.
+// nolint:interfacer
+func NewQuerySpendableBalancesRequest(addr sdk.AccAddress, req *query.PageRequest) *QuerySpendableBalancesRequest {
+	return &QuerySpendableBalancesRequest{Address: addr.String(), Pagination: req}
+}
+
 // QueryTotalSupplyParams defines the params for the following queries:
 //
 // - 'custom/bank/totalSupply'