chore: add channel consensus state rpc (#7619)

modules/core/04-channel/v2/keeper/grpc_query.go

@@ -78,6 +78,38 @@ func (q *queryServer) ChannelClientState(ctx context.Context, req *types.QueryCh
 	return res, nil
 }
 
+// ChannelConsensusState implements the Query/ChannelConsensusState gRPC method
+func (q *queryServer) ChannelConsensusState(ctx context.Context, req *types.QueryChannelConsensusStateRequest) (*types.QueryChannelConsensusStateResponse, error) {
+	if req == nil {
+		return nil, status.Error(codes.InvalidArgument, "empty request")
+	}
+
+	if err := host.ChannelIdentifierValidator(req.ChannelId); err != nil {
+		return nil, status.Error(codes.InvalidArgument, err.Error())
+	}
+
+	channel, found := q.GetChannel(ctx, req.ChannelId)
+	if !found {
+		return nil, status.Error(codes.NotFound, errorsmod.Wrapf(types.ErrChannelNotFound, "channel-id: %s", req.ChannelId).Error())
+	}
+
+	consHeight := clienttypes.NewHeight(req.RevisionNumber, req.RevisionHeight)
+	consensusState, found := q.ClientKeeper.GetClientConsensusState(ctx, channel.ClientId, consHeight)
+	if !found {
+		return nil, status.Error(
+			codes.NotFound,
+			errorsmod.Wrapf(clienttypes.ErrConsensusStateNotFound, "client-id: %s", channel.ClientId).Error(),
+		)
+	}
+
+	anyConsensusState, err := clienttypes.PackConsensusState(consensusState)
+	if err != nil {
+		return nil, status.Error(codes.Internal, err.Error())
+	}
+
+	return types.NewQueryChannelConsensusStateResponse(channel.ClientId, anyConsensusState, nil, clienttypes.GetSelfHeight(ctx)), nil
+}
+
 // NextSequenceSend implements the Query/NextSequenceSend gRPC method
 func (q *queryServer) NextSequenceSend(ctx context.Context, req *types.QueryNextSequenceSendRequest) (*types.QueryNextSequenceSendResponse, error) {
 	if req == nil {

modules/core/04-channel/v2/keeper/grpc_query_test.go

@@ -12,6 +12,7 @@ import (
 	"github.com/cosmos/ibc-go/v9/modules/core/04-channel/v2/keeper"
 	"github.com/cosmos/ibc-go/v9/modules/core/04-channel/v2/types"
 	commitmenttypes "github.com/cosmos/ibc-go/v9/modules/core/23-commitment/types"
+	"github.com/cosmos/ibc-go/v9/modules/core/exported"
 	ibctesting "github.com/cosmos/ibc-go/v9/testing"
 )
 
@@ -190,6 +191,113 @@ func (suite *KeeperTestSuite) TestQueryChannelClientState() {
 	}
 }
 
+func (suite *KeeperTestSuite) TestQueryChannelConsensusState() {
+	var (
+		req               *types.QueryChannelConsensusStateRequest
+		expConsensusState exported.ConsensusState
+		expClientID       string
+	)
+
+	testCases := []struct {
+		msg      string
+		malleate func()
+		expError error
+	}{
+		{
+			"success",
+			func() {
+				path := ibctesting.NewPath(suite.chainA, suite.chainB)
+				path.SetupV2()
+
+				expConsensusState, _ = suite.chainA.GetConsensusState(path.EndpointA.ClientID, path.EndpointA.GetClientLatestHeight())
+				suite.Require().NotNil(expConsensusState)
+				expClientID = path.EndpointA.ClientID
+
+				req = &types.QueryChannelConsensusStateRequest{
+					ChannelId:      path.EndpointA.ChannelID,
+					RevisionNumber: path.EndpointA.GetClientLatestHeight().GetRevisionNumber(),
+					RevisionHeight: path.EndpointA.GetClientLatestHeight().GetRevisionHeight(),
+				}
+			},
+			nil,
+		},
+		{
+			"empty request",
+			func() {
+				req = nil
+			},
+			status.Error(codes.InvalidArgument, "empty request"),
+		},
+		{
+			"invalid channel ID",
+			func() {
+				req = &types.QueryChannelConsensusStateRequest{
+					ChannelId:      "",
+					RevisionNumber: 0,
+					RevisionHeight: 1,
+				}
+			},
+			status.Error(codes.InvalidArgument, "identifier cannot be blank: invalid identifier"),
+		},
+		{
+			"channel not found",
+			func() {
+				req = &types.QueryChannelConsensusStateRequest{
+					ChannelId:      "test-channel-id",
+					RevisionNumber: 0,
+					RevisionHeight: 1,
+				}
+			},
+			status.Error(codes.NotFound, fmt.Sprintf("channel-id: %s: channel not found", "test-channel-id")),
+		},
+		{
+			"consensus state for channel's connection not found",
+			func() {
+				path := ibctesting.NewPath(suite.chainA, suite.chainB)
+				path.SetupV2()
+
+				req = &types.QueryChannelConsensusStateRequest{
+					ChannelId:      path.EndpointA.ChannelID,
+					RevisionNumber: 0,
+					RevisionHeight: uint64(suite.chainA.GetContext().BlockHeight()), // use current height
+				}
+			},
+			status.Error(codes.NotFound, fmt.Sprintf("client-id: %s: consensus state not found", "07-tendermint-0")),
+		},
+	}
+
+	for _, tc := range testCases {
+		tc := tc
+
+		suite.Run(fmt.Sprintf("Case %s", tc.msg), func() {
+			suite.SetupTest() // reset
+
+			tc.malleate()
+			ctx := suite.chainA.GetContext()
+
+			queryServer := keeper.NewQueryServer(suite.chainA.App.GetIBCKeeper().ChannelKeeperV2)
+			res, err := queryServer.ChannelConsensusState(ctx, req)
+
+			expPass := tc.expError == nil
+			if expPass {
+				suite.Require().NoError(err)
+				suite.Require().NotNil(res)
+				consensusState, err := clienttypes.UnpackConsensusState(res.ConsensusState)
+				suite.Require().NoError(err)
+				suite.Require().Equal(expConsensusState, consensusState)
+				suite.Require().Equal(expClientID, res.ClientId)
+
+				// ensure UnpackInterfaces is defined
+				cachedValue := res.ConsensusState.GetCachedValue()
+				suite.Require().NotNil(cachedValue)
+			} else {
+				suite.Require().ErrorIs(err, tc.expError)
+				suite.Require().Nil(res)
+			}
+		})
+	}
+}
+
 func (suite *KeeperTestSuite) TestQueryPacketCommitment() {
 	var (
 		expCommitment []byte

modules/core/04-channel/v2/types/expected_keepers.go

@@ -21,4 +21,6 @@ type ClientKeeper interface {
 	GetClientTimestampAtHeight(ctx context.Context, clientID string, height exported.Height) (uint64, error)
 	// GetClientState gets a particular client from the store
 	GetClientState(ctx context.Context, clientID string) (exported.ClientState, bool)
+	// GetClientConsensusState gets the stored consensus state from a client at a given height.
+	GetClientConsensusState(ctx context.Context, clientID string, height exported.Height) (exported.ConsensusState, bool)
 }

modules/core/04-channel/v2/types/query.go

@@ -1,6 +1,10 @@
 package types
 
-import clienttypes "github.com/cosmos/ibc-go/v9/modules/core/02-client/types"
+import (
+	codectypes "github.com/cosmos/cosmos-sdk/codec/types"
+
+	clienttypes "github.com/cosmos/ibc-go/v9/modules/core/02-client/types"
+)
 
 // NewQueryChannelRequest creates and returns a new channel query request.
 func NewQueryChannelRequest(channelID string) *QueryChannelRequest {
@@ -32,6 +36,16 @@ func NewQueryChannelClientStateResponse(identifiedClientState clienttypes.Identi
 	}
 }
 
+// NewQueryChannelConsensusStateResponse creates and returns a new ChannelConsensusState query response.
+func NewQueryChannelConsensusStateResponse(clientID string, anyConsensusState *codectypes.Any, proof []byte, height clienttypes.Height) *QueryChannelConsensusStateResponse {
+	return &QueryChannelConsensusStateResponse{
+		ConsensusState: anyConsensusState,
+		ClientId:       clientID,
+		Proof:          proof,
+		ProofHeight:    height,
+	}
+}
+
 // NewQueryNextSequenceSendRequest creates a new next sequence send query.
 func NewQueryNextSequenceSendRequest(channelID string) *QueryNextSequenceSendRequest {
 	return &QueryNextSequenceSendRequest{