chore: adding type alias for code hash byte slices (#5004)

* chore: adding type alias for code hash byte slices

* chore: adjust tests and add type conversions for code hashes

* chore: initialise slice in favour of nil declaration

modules/light-clients/08-wasm/keeper/genesis.go

@@ -1,6 +1,8 @@
 package keeper
 
 import (
+	wasmvmtypes "github.com/CosmWasm/wasmvm/types"
+
 	sdk "github.com/cosmos/cosmos-sdk/types"
 
 	"github.com/cosmos/ibc-go/modules/light-clients/08-wasm/types"
@@ -29,7 +31,7 @@ func (k Keeper) ExportGenesis(ctx sdk.Context) types.GenesisState {
 	// Grab code from wasmVM and add to genesis state.
 	var genesisState types.GenesisState
 	for _, codeHash := range codeHashes {
-		code, err := k.wasmVM.GetCode(codeHash)
+		code, err := k.wasmVM.GetCode(wasmvmtypes.Checksum(codeHash))
 		if err != nil {
 			panic(err)
 		}

modules/light-clients/08-wasm/keeper/genesis_test.go

@@ -59,7 +59,6 @@ func (suite *KeeperTestSuite) TestInitGenesis() {
 			var storedHashes []string
 			codeHashes, err := types.GetAllCodeHashes(suite.chainA.GetContext())
 			suite.Require().NoError(err)
-			suite.Require().NotNil(codeHashes)
 
 			for _, hash := range codeHashes {
 				storedHashes = append(storedHashes, hex.EncodeToString(hash))

modules/light-clients/08-wasm/keeper/snapshotter.go

@@ -4,6 +4,8 @@ import (
 	"encoding/hex"
 	"io"
 
+	wasmvmtypes "github.com/CosmWasm/wasmvm/types"
+
 	errorsmod "cosmossdk.io/errors"
 	snapshot "cosmossdk.io/store/snapshots/types"
 	storetypes "cosmossdk.io/store/types"
@@ -72,7 +74,7 @@ func (ws *WasmSnapshotter) SnapshotExtension(height uint64, payloadWriter snapsh
 	}
 
 	for _, codeHash := range codeHashes {
-		wasmCode, err := ws.keeper.wasmVM.GetCode(codeHash)
+		wasmCode, err := ws.keeper.wasmVM.GetCode(wasmvmtypes.Checksum(codeHash))
 		if err != nil {
 			return err
 		}

modules/light-clients/08-wasm/types/wasm.go

@@ -6,29 +6,33 @@ import (
 	"github.com/cosmos/ibc-go/modules/light-clients/08-wasm/internal/ibcwasm"
 )
 
+// CodeHash is a type alias used for wasm byte code checksums.
+type CodeHash []byte
+
 // GetAllCodeHashes is a helper to get all code hashes from the store.
 // It returns an empty slice if no code hashes are found
-func GetAllCodeHashes(ctx sdk.Context) ([][]byte, error) {
+func GetAllCodeHashes(ctx sdk.Context) ([]CodeHash, error) {
 	iterator, err := ibcwasm.CodeHashes.Iterate(ctx, nil)
 	if err != nil {
 		return nil, err
 	}
 
-	codeHashes, err := iterator.Keys()
+	keys, err := iterator.Keys()
 	if err != nil {
 		return nil, err
 	}
 
-	if codeHashes == nil {
-		codeHashes = [][]byte{}
+	codeHashes := []CodeHash{}
+	for _, key := range keys {
+		codeHashes = append(codeHashes, key)
 	}
 
 	return codeHashes, nil
 }
 
 // HasCodeHash returns true if the given code hash exists in the store and
 // false otherwise.
-func HasCodeHash(ctx sdk.Context, codeHash []byte) bool {
+func HasCodeHash(ctx sdk.Context, codeHash CodeHash) bool {
 	found, err := ibcwasm.CodeHashes.Has(ctx, codeHash)
 	if err != nil {
 		return false

modules/light-clients/08-wasm/types/wasm_test.go

@@ -12,12 +12,12 @@ func (suite *TypesTestSuite) TestGetCodeHashes() {
 	testCases := []struct {
 		name      string
 		malleate  func()
-		expResult func(codeHashes [][]byte)
+		expResult func(codeHashes []types.CodeHash)
 	}{
 		{
 			"success: no contract stored.",
 			func() {},
-			func(codeHashes [][]byte) {
+			func(codeHashes []types.CodeHash) {
 				suite.Require().Len(codeHashes, 0)
 			},
 		},
@@ -26,23 +26,23 @@ func (suite *TypesTestSuite) TestGetCodeHashes() {
 			func() {
 				suite.SetupWasmWithMockVM()
 			},
-			func(codeHashes [][]byte) {
+			func(codeHashes []types.CodeHash) {
 				suite.Require().Len(codeHashes, 1)
 				expectedCodeHash := sha256.Sum256(wasmtesting.Code)
-				suite.Require().Equal(expectedCodeHash[:], codeHashes[0])
+				suite.Require().Equal(types.CodeHash(expectedCodeHash[:]), codeHashes[0])
 			},
 		},
 		{
 			"success: non-empty code hashes",
 			func() {
 				suite.SetupWasmWithMockVM()
 
-				err := ibcwasm.CodeHashes.Set(suite.chainA.GetContext(), []byte("codehash"))
+				err := ibcwasm.CodeHashes.Set(suite.chainA.GetContext(), types.CodeHash("codehash"))
 				suite.Require().NoError(err)
 			},
-			func(codeHashes [][]byte) {
+			func(codeHashes []types.CodeHash) {
 				suite.Require().Len(codeHashes, 2)
-				suite.Require().Contains(codeHashes, []byte("codehash"))
+				suite.Require().Contains(codeHashes, types.CodeHash("codehash"))
 			},
 		},
 	}
@@ -67,8 +67,8 @@ func (suite *TypesTestSuite) TestAddCodeHash() {
 	// default mock vm contract is stored
 	suite.Require().Len(codeHashes, 1)
 
-	codeHash1 := []byte("codehash1")
-	codeHash2 := []byte("codehash2")
+	codeHash1 := types.CodeHash("codehash1")
+	codeHash2 := types.CodeHash("codehash2")
 	err = ibcwasm.CodeHashes.Set(suite.chainA.GetContext(), codeHash1)
 	suite.Require().NoError(err)
 	err = ibcwasm.CodeHashes.Set(suite.chainA.GetContext(), codeHash2)
@@ -86,7 +86,7 @@ func (suite *TypesTestSuite) TestAddCodeHash() {
 }
 
 func (suite *TypesTestSuite) TestHasCodeHash() {
-	var codeHash []byte
+	var codeHash types.CodeHash
 
 	testCases := []struct {
 		name       string
@@ -96,7 +96,7 @@ func (suite *TypesTestSuite) TestHasCodeHash() {
 		{
 			"success: code hash exists",
 			func() {
-				codeHash = []byte("codehash")
+				codeHash = types.CodeHash("codehash")
 				err := ibcwasm.CodeHashes.Set(suite.chainA.GetContext(), codeHash)
 				suite.Require().NoError(err)
 			},
@@ -105,7 +105,7 @@ func (suite *TypesTestSuite) TestHasCodeHash() {
 		{
 			"success: code hash does not exist",
 			func() {
-				codeHash = []byte("non-existent-codehash")
+				codeHash = types.CodeHash("non-existent-codehash")
 			},
 			false,
 		},