x/mint: gRPC query service (cosmos#6535)

* Added grpc for mint

* changed unused params

* updated tests

* removed empty query request

* fixed lint issues

* review changes

* review changes

* migrated to use test suite

* Update x/mint/keeper/grpc_query_test.go

Co-authored-by: SaReN <sahithnarahari@gmail.com>
Co-authored-by: Federico Kunze <31522760+fedekunze@users.noreply.github.com>

proto/cosmos/mint/query.proto

@@ -0,0 +1,43 @@
+syntax = "proto3";
+package cosmos.mint;
+
+import "gogoproto/gogo.proto";
+import "cosmos/mint/mint.proto";
+
+option go_package = "github.com/cosmos/cosmos-sdk/x/mint/types";
+
+// Query provides defines the gRPC querier service
+service Query {
+  // Params returns the total set of minting parameters.
+  rpc Params (QueryParamsRequest) returns (QueryParamsResponse) {}
+
+  // Inflation returns the current minting inflation value.
+  rpc Inflation (QueryInflationRequest) returns (QueryInflationResponse) {}
+
+  // AnnualProvisions current minting annual provisions value.
+  rpc AnnualProvisions (QueryAnnualProvisionsRequest) returns (QueryAnnualProvisionsResponse) {}
+}
+
+// QueryParamsRequest is the request type for the Query/Params RPC method
+message QueryParamsRequest { }
+
+// QueryParamsResponse is the response type for the Query/Params RPC method
+message QueryParamsResponse {
+  Params params = 1 [(gogoproto.nullable) = false];
+}
+
+// QueryInflationRequest is the request type for the Query/Inflation RPC method
+message QueryInflationRequest { }
+
+// QueryInflationResponse is the response type for the Query/Inflation RPC method
+message QueryInflationResponse {
+  bytes inflation = 1 [(gogoproto.customtype) = "github.com/cosmos/cosmos-sdk/types.Dec", (gogoproto.nullable) = false];
+}
+
+// QueryAnnualProvisionsRequest is the request type for the Query/AnnualProvisions RPC method
+message QueryAnnualProvisionsRequest { }
+
+// QueryAnnualProvisionsResponse is the response type for the Query/AnnualProvisions RPC method
+message QueryAnnualProvisionsResponse {
+  bytes annual_provisions = 1 [(gogoproto.customtype) = "github.com/cosmos/cosmos-sdk/types.Dec", (gogoproto.nullable) = false];
+}

x/mint/keeper/grpc_query.go

@@ -0,0 +1,34 @@
+package keeper
+
+import (
+	"context"
+
+	sdk "github.com/cosmos/cosmos-sdk/types"
+	"github.com/cosmos/cosmos-sdk/x/mint/types"
+)
+
+var _ types.QueryServer = Keeper{}
+
+// Params returns params of the mint module.
+func (k Keeper) Params(c context.Context, _ *types.QueryParamsRequest) (*types.QueryParamsResponse, error) {
+	ctx := sdk.UnwrapSDKContext(c)
+	params := k.GetParams(ctx)
+
+	return &types.QueryParamsResponse{Params: params}, nil
+}
+
+// Inflation returns minter.Inflation of the mint module.
+func (k Keeper) Inflation(c context.Context, _ *types.QueryInflationRequest) (*types.QueryInflationResponse, error) {
+	ctx := sdk.UnwrapSDKContext(c)
+	minter := k.GetMinter(ctx)
+
+	return &types.QueryInflationResponse{Inflation: minter.Inflation}, nil
+}
+
+// AnnualProvisions returns minter.AnnualProvisions of the mint module.
+func (k Keeper) AnnualProvisions(c context.Context, _ *types.QueryAnnualProvisionsRequest) (*types.QueryAnnualProvisionsResponse, error) {
+	ctx := sdk.UnwrapSDKContext(c)
+	minter := k.GetMinter(ctx)
+
+	return &types.QueryAnnualProvisionsResponse{AnnualProvisions: minter.AnnualProvisions}, nil
+}

x/mint/keeper/grpc_query_test.go

@@ -0,0 +1,55 @@
+package keeper_test
+
+import (
+	gocontext "context"
+	"testing"
+
+	"github.com/cosmos/cosmos-sdk/baseapp"
+	"github.com/cosmos/cosmos-sdk/simapp"
+	sdk "github.com/cosmos/cosmos-sdk/types"
+	"github.com/cosmos/cosmos-sdk/x/mint/types"
+	"github.com/stretchr/testify/suite"
+	abci "github.com/tendermint/tendermint/abci/types"
+)
+
+type MintTestSuite struct {
+	suite.Suite
+
+	app         *simapp.SimApp
+	ctx         sdk.Context
+	queryClient types.QueryClient
+}
+
+func (suite *MintTestSuite) SetupTest() {
+	app := simapp.Setup(false)
+	ctx := app.BaseApp.NewContext(false, abci.Header{})
+
+	queryHelper := baseapp.NewQueryServerTestHelper(ctx, app.InterfaceRegistry())
+	types.RegisterQueryServer(queryHelper, app.MintKeeper)
+	queryClient := types.NewQueryClient(queryHelper)
+
+	suite.app = app
+	suite.ctx = ctx
+
+	suite.queryClient = queryClient
+}
+
+func (suite *MintTestSuite) TestGRPCParams() {
+	app, ctx, queryClient := suite.app, suite.ctx, suite.queryClient
+
+	params, err := queryClient.Params(gocontext.Background(), &types.QueryParamsRequest{})
+	suite.Require().NoError(err)
+	suite.Require().Equal(params.Params, app.MintKeeper.GetParams(ctx))
+
+	inflation, err := queryClient.Inflation(gocontext.Background(), &types.QueryInflationRequest{})
+	suite.Require().NoError(err)
+	suite.Require().Equal(inflation.Inflation, app.MintKeeper.GetMinter(ctx).Inflation)
+
+	annualProvisions, err := queryClient.AnnualProvisions(gocontext.Background(), &types.QueryAnnualProvisionsRequest{})
+	suite.Require().NoError(err)
+	suite.Require().Equal(annualProvisions.AnnualProvisions, app.MintKeeper.GetMinter(ctx).AnnualProvisions)
+}
+
+func TestMintTestSuite(t *testing.T) {
+	suite.Run(t, new(MintTestSuite))
+}