added function to check for empty keeper

CHANGELOG.md

@@ -115,7 +115,7 @@ Ref: https://keepachangelog.com/en/1.0.0/
 * (light-clients/solomachine) [#1839](https://github.com/cosmos/ibc-go/issues/1839) Fixed usage of the new diversifier in validation of changing diversifiers for the solo machine. The current diversifier must sign over the new diversifier.
 * (light-clients/07-tendermint) [\#1674](https://github.com/cosmos/ibc-go/pull/1674) Submitted ClientState is zeroed out before checking the proof in order to prevent the proposal from containing information governance is not actually voting on.
 * (modules/core/02-client)[\#1676](https://github.com/cosmos/ibc-go/pull/1676) ClientState must be zeroed out for `UpgradeProposals` to pass validation. This prevents a proposal containing information governance is not actually voting on.
-* (modules/core/keeper) [\#2268](https://github.com/cosmos/ibc-go/pull/2403) Added switch case in NewKeeper to cater for blank pointers.
+* (modules/core/keeper) [\#2268](https://github.com/cosmos/ibc-go/pull/2403) Added a function in keeper to cater for blank pointers.
 
 ## [v4.1.0](https://github.com/cosmos/ibc-go/releases/tag/v4.1.0) - 2022-09-20
 

modules/core/keeper/keeper.go

@@ -50,28 +50,11 @@ func NewKeeper(
 	}
 
 	// panic if any of the keepers passed in is empty
-
-	// switch case to detect blank pointers
-	switch reflect.TypeOf(stakingKeeper).Kind() {
-	case reflect.Ptr:
-		if reflect.ValueOf(stakingKeeper).Elem().IsZero() {
-			panic(fmt.Errorf("cannot initialize IBC keeper: empty staking keeper pointer"))
-		}
-	default:
-		if reflect.ValueOf(stakingKeeper).IsZero() {
-			panic(fmt.Errorf("cannot initialize IBC keeper: empty staking keeper value"))
-		}
+	if isEmpty(stakingKeeper) {
+		panic(fmt.Errorf("cannot initialize IBC keeper: empty staking keeper"))
 	}
-
-	switch reflect.TypeOf(upgradeKeeper).Kind() {
-	case reflect.Ptr:
-		if reflect.ValueOf(upgradeKeeper).Elem().IsZero() {
-			panic(fmt.Errorf("cannot initialize IBC keeper: empty upgrade keeper pointer"))
-		}
-	default:
-		if reflect.ValueOf(upgradeKeeper).IsZero() {
-			panic(fmt.Errorf("cannot initialize IBC keeper: empty upgrade keeper value"))
-		}
+	if isEmpty(upgradeKeeper) {
+		panic(fmt.Errorf("cannot initialize IBC keeper: empty upgrade keeper"))
 	}
 
 	if reflect.DeepEqual(capabilitykeeper.ScopedKeeper{}, scopedKeeper) {
@@ -108,3 +91,19 @@ func (k *Keeper) SetRouter(rtr *porttypes.Router) {
 	k.Router = rtr
 	k.Router.Seal()
 }
+
+// isEmpty checks if the interface is an empty struct or a pointer pointing
+// to an empty struct
+func isEmpty(keeper interface{}) bool {
+	switch reflect.TypeOf(keeper).Kind() {
+	case reflect.Ptr:
+		if reflect.ValueOf(keeper).Elem().IsZero() {
+			return true
+		}
+	default:
+		if reflect.ValueOf(keeper).IsZero() {
+			return true
+		}
+	}
+	return false
+}