Save gas on IsFeeEnabled (#2786) (#2817)

improvements: save some gas in fee keeper

Author: mergify[bot]

CHANGELOG.md

@@ -77,6 +77,7 @@ Ref: https://keepachangelog.com/en/1.0.0/
 * (modules/core/keeper) [\#1728](https://github.com/cosmos/ibc-go/pull/2399) Updated channel callback errors to include portID & channelID for better identification of errors.
 * (testing) [\#2657](https://github.com/cosmos/ibc-go/pull/2657) Carry `ProposerAddress` through commited blocks. Allow `DefaultGenTxGas` to be modified.
 * (core/03-connection) [\#2745](https://github.com/cosmos/ibc-go/pull/2745) Adding `ConnectionParams` grpc query and CLI to 03-connection.
+* (apps/29-fee) [\#2786](https://github.com/cosmos/ibc-go/pull/2786) Save gas by checking key existence with `KVStore`'s `Has` method.
 
 ### Features
 

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

@@ -123,7 +123,7 @@ func (k Keeper) DeleteFeeEnabled(ctx sdk.Context, portID, channelID string) {
 // fee enabled flag for the given port and channel identifiers
 func (k Keeper) IsFeeEnabled(ctx sdk.Context, portID, channelID string) bool {
 	store := ctx.KVStore(k.storeKey)
-	return store.Get(types.KeyFeeEnabled(portID, channelID)) != nil
+	return store.Has(types.KeyFeeEnabled(portID, channelID))
 }
 
 // GetAllFeeEnabledChannels returns a list of all ics29 enabled channels containing portID & channelID that are stored in state