imp(channel, connection): add Has function for ConnectionEnd and Channel

CHANGELOG.md

@@ -68,6 +68,7 @@ Ref: https://keepachangelog.com/en/1.0.0/
 
 ### Improvements
 
+* (core) [\#3082](https://github.com/cosmos/ibc-go/pull/3082) Add `HasConnection` and `HasChannel` methods.
 * (tests) [\#2926](https://github.com/cosmos/ibc-go/pull/2926) Lint tests
 * (apps/transfer) [\#2643](https://github.com/cosmos/ibc-go/pull/2643) Add amount, denom, and memo to transfer event emission.
 * (core) [\#2746](https://github.com/cosmos/ibc-go/pull/2746) Allow proof height to be zero for all core IBC `sdk.Msg` types that contain proofs.

modules/apps/29-fee/keeper/keeper.go

@@ -291,7 +291,7 @@ func (k Keeper) GetFeesInEscrow(ctx sdk.Context, packetID channeltypes.PacketId)
 	store := ctx.KVStore(k.storeKey)
 	key := types.KeyFeesInEscrow(packetID)
 	bz := store.Get(key)
-	if bz == nil {
+	if len(bz) == 0 {
 		return types.PacketFees{}, false
 	}
 

modules/apps/transfer/keeper/keeper.go

@@ -93,7 +93,7 @@ func (k Keeper) SetPort(ctx sdk.Context, portID string) {
 func (k Keeper) GetDenomTrace(ctx sdk.Context, denomTraceHash tmbytes.HexBytes) (types.DenomTrace, bool) {
 	store := prefix.NewStore(ctx.KVStore(k.storeKey), types.DenomTraceKey)
 	bz := store.Get(denomTraceHash)
-	if bz == nil {
+	if len(bz) == 0 {
 		return types.DenomTrace{}, false
 	}
 

modules/core/02-client/keeper/keeper.go

@@ -67,7 +67,7 @@ func (k Keeper) GenerateClientIdentifier(ctx sdk.Context, clientType string) str
 func (k Keeper) GetClientState(ctx sdk.Context, clientID string) (exported.ClientState, bool) {
 	store := k.ClientStore(ctx, clientID)
 	bz := store.Get(host.ClientStateKey())
-	if bz == nil {
+	if len(bz) == 0 {
 		return nil, false
 	}
 
@@ -85,7 +85,7 @@ func (k Keeper) SetClientState(ctx sdk.Context, clientID string, clientState exp
 func (k Keeper) GetClientConsensusState(ctx sdk.Context, clientID string, height exported.Height) (exported.ConsensusState, bool) {
 	store := k.ClientStore(ctx, clientID)
 	bz := store.Get(host.ConsensusStateKey(height))
-	if bz == nil {
+	if len(bz) == 0 {
 		return nil, false
 	}
 
@@ -104,7 +104,7 @@ func (k Keeper) SetClientConsensusState(ctx sdk.Context, clientID string, height
 func (k Keeper) GetNextClientSequence(ctx sdk.Context) uint64 {
 	store := ctx.KVStore(k.storeKey)
 	bz := store.Get([]byte(types.KeyNextClientSequence))
-	if bz == nil {
+	if len(bz) == 0 {
 		panic("next client sequence is nil")
 	}
 

modules/core/02-client/migrations/v7/store.go

@@ -58,7 +58,7 @@ func handleSolomachineMigration(ctx sdk.Context, store sdk.KVStore, cdc codec.Bi
 		clientStore := clientKeeper.ClientStore(ctx, clientID)
 
 		bz := clientStore.Get(host.ClientStateKey())
-		if bz == nil {
+		if len(bz) == 0 {
 			return sdkerrors.Wrapf(clienttypes.ErrClientNotFound, "clientID %s", clientID)
 		}
 

modules/core/03-connection/keeper/keeper.go

@@ -66,7 +66,7 @@ func (k Keeper) GenerateConnectionIdentifier(ctx sdk.Context) string {
 func (k Keeper) GetConnection(ctx sdk.Context, connectionID string) (types.ConnectionEnd, bool) {
 	store := ctx.KVStore(k.storeKey)
 	bz := store.Get(host.ConnectionKey(connectionID))
-	if bz == nil {
+	if len(bz) == 0 {
 		return types.ConnectionEnd{}, false
 	}
 
@@ -76,6 +76,13 @@ func (k Keeper) GetConnection(ctx sdk.Context, connectionID string) (types.Conne
 	return connection, true
 }
 
+// HasConnection returns a true if the connection with the given identifier
+// exists in the store.
+func (k Keeper) HasConnection(ctx sdk.Context, connectionID string) bool {
+	store := ctx.KVStore(k.storeKey)
+	return store.Has(host.ConnectionKey(connectionID))
+}
+
 // SetConnection sets a connection to the store
 func (k Keeper) SetConnection(ctx sdk.Context, connectionID string, connection types.ConnectionEnd) {
 	store := ctx.KVStore(k.storeKey)
@@ -106,7 +113,7 @@ func (k Keeper) GetTimestampAtHeight(ctx sdk.Context, connection types.Connectio
 func (k Keeper) GetClientConnectionPaths(ctx sdk.Context, clientID string) ([]string, bool) {
 	store := ctx.KVStore(k.storeKey)
 	bz := store.Get(host.ClientConnectionsKey(clientID))
-	if bz == nil {
+	if len(bz) == 0 {
 		return nil, false
 	}
 
@@ -127,7 +134,7 @@ func (k Keeper) SetClientConnectionPaths(ctx sdk.Context, clientID string, paths
 func (k Keeper) GetNextConnectionSequence(ctx sdk.Context) uint64 {
 	store := ctx.KVStore(k.storeKey)
 	bz := store.Get([]byte(types.KeyNextConnectionSequence))
-	if bz == nil {
+	if len(bz) == 0 {
 		panic("next connection sequence is nil")
 	}
 

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

@@ -66,11 +66,17 @@ func (k Keeper) GenerateChannelIdentifier(ctx sdk.Context) string {
 	return channelID
 }
 
+// HasChannel true if the channel with the given identifiers exists in state.
+func (k Keeper) HasChannel(ctx sdk.Context, portID, channelID string) bool {
+	store := ctx.KVStore(k.storeKey)
+	return store.Has(host.ChannelKey(portID, channelID))
+}
+
 // GetChannel returns a channel with a particular identifier binded to a specific port
 func (k Keeper) GetChannel(ctx sdk.Context, portID, channelID string) (types.Channel, bool) {
 	store := ctx.KVStore(k.storeKey)
 	bz := store.Get(host.ChannelKey(portID, channelID))
-	if bz == nil {
+	if len(bz) == 0 {
 		return types.Channel{}, false
 	}
 
@@ -100,7 +106,7 @@ func (k Keeper) GetAppVersion(ctx sdk.Context, portID, channelID string) (string
 func (k Keeper) GetNextChannelSequence(ctx sdk.Context) uint64 {
 	store := ctx.KVStore(k.storeKey)
 	bz := store.Get([]byte(types.KeyNextChannelSequence))
-	if bz == nil {
+	if len(bz) == 0 {
 		panic("next channel sequence is nil")
 	}
 
@@ -118,7 +124,7 @@ func (k Keeper) SetNextChannelSequence(ctx sdk.Context, sequence uint64) {
 func (k Keeper) GetNextSequenceSend(ctx sdk.Context, portID, channelID string) (uint64, bool) {
 	store := ctx.KVStore(k.storeKey)
 	bz := store.Get(host.NextSequenceSendKey(portID, channelID))
-	if bz == nil {
+	if len(bz) == 0 {
 		return 0, false
 	}
 
@@ -136,7 +142,7 @@ func (k Keeper) SetNextSequenceSend(ctx sdk.Context, portID, channelID string, s
 func (k Keeper) GetNextSequenceRecv(ctx sdk.Context, portID, channelID string) (uint64, bool) {
 	store := ctx.KVStore(k.storeKey)
 	bz := store.Get(host.NextSequenceRecvKey(portID, channelID))
-	if bz == nil {
+	if len(bz) == 0 {
 		return 0, false
 	}
 
@@ -154,7 +160,7 @@ func (k Keeper) SetNextSequenceRecv(ctx sdk.Context, portID, channelID string, s
 func (k Keeper) GetNextSequenceAck(ctx sdk.Context, portID, channelID string) (uint64, bool) {
 	store := ctx.KVStore(k.storeKey)
 	bz := store.Get(host.NextSequenceAckKey(portID, channelID))
-	if bz == nil {
+	if len(bz) == 0 {
 		return 0, false
 	}
 
@@ -172,7 +178,7 @@ func (k Keeper) SetNextSequenceAck(ctx sdk.Context, portID, channelID string, se
 func (k Keeper) GetPacketReceipt(ctx sdk.Context, portID, channelID string, sequence uint64) (string, bool) {
 	store := ctx.KVStore(k.storeKey)
 	bz := store.Get(host.PacketReceiptKey(portID, channelID, sequence))
-	if bz == nil {
+	if len(bz) == 0 {
 		return "", false
 	}
 
@@ -219,7 +225,7 @@ func (k Keeper) SetPacketAcknowledgement(ctx sdk.Context, portID, channelID stri
 func (k Keeper) GetPacketAcknowledgement(ctx sdk.Context, portID, channelID string, sequence uint64) ([]byte, bool) {
 	store := ctx.KVStore(k.storeKey)
 	bz := store.Get(host.PacketAcknowledgementKey(portID, channelID, sequence))
-	if bz == nil {
+	if len(bz) == 0 {
 		return nil, false
 	}
 	return bz, true

modules/core/04-channel/keeper/keeper_test.go

@@ -46,7 +46,7 @@ func (suite *KeeperTestSuite) TestSetChannel() {
 	suite.coordinator.SetupConnections(path)
 
 	// check for channel to be created on chainA
-	_, found := suite.chainA.App.GetIBCKeeper().ChannelKeeper.GetChannel(suite.chainA.GetContext(), path.EndpointA.ChannelConfig.PortID, path.EndpointA.ChannelID)
+	found := suite.chainA.App.GetIBCKeeper().ChannelKeeper.HasChannel(suite.chainA.GetContext(), path.EndpointA.ChannelConfig.PortID, path.EndpointA.ChannelID)
 	suite.False(found)
 
 	path.SetChannelOrdered()

modules/light-clients/07-tendermint/store.go

@@ -60,7 +60,7 @@ func setConsensusState(clientStore sdk.KVStore, cdc codec.BinaryCodec, consensus
 // If the ConsensusState does not exist in state for the provided height a nil value and false boolean flag is returned
 func GetConsensusState(store sdk.KVStore, cdc codec.BinaryCodec, height exported.Height) (*ConsensusState, bool) {
 	bz := store.Get(host.ConsensusStateKey(height))
-	if bz == nil {
+	if len(bz) == 0 {
 		return nil, false
 	}
 
@@ -129,7 +129,7 @@ func SetProcessedTime(clientStore sdk.KVStore, height exported.Height, timeNs ui
 func GetProcessedTime(clientStore sdk.KVStore, height exported.Height) (uint64, bool) {
 	key := ProcessedTimeKey(height)
 	bz := clientStore.Get(key)
-	if bz == nil {
+	if len(bz) == 0 {
 		return 0, false
 	}
 	return sdk.BigEndianToUint64(bz), true
@@ -160,7 +160,7 @@ func SetProcessedHeight(clientStore sdk.KVStore, consHeight, processedHeight exp
 func GetProcessedHeight(clientStore sdk.KVStore, height exported.Height) (exported.Height, bool) {
 	key := ProcessedHeightKey(height)
 	bz := clientStore.Get(key)
-	if bz == nil {
+	if len(bz) == 0 {
 		return nil, false
 	}
 	processedHeight, err := clienttypes.ParseHeight(string(bz))
@@ -306,7 +306,7 @@ func PruneAllExpiredConsensusStates(
 // Helper function for GetNextConsensusState and GetPreviousConsensusState
 func getTmConsensusState(clientStore sdk.KVStore, cdc codec.BinaryCodec, key []byte) (*ConsensusState, bool) {
 	bz := clientStore.Get(key)
-	if bz == nil {
+	if len(bz) == 0 {
 		return nil, false
 	}