fix: add error message in GetByteCode()

CHANGELOG.md

@@ -88,6 +88,7 @@ Ref: https://keepachangelog.com/en/1.0.0/
 * (x/foundation) [\#729](https://github.com/line/lbm-sdk/pull/729) add UpdateParams to x/foundation
 * (amino) [\#736](https://github.com/line/lbm-sdk/pull/736) apply the missing amino codec registratoin of cosmos-sdk
 * (x/foundation) [\#744](https://github.com/line/lbm-sdk/pull/744) revisit foundation operator
+* (store,x/wasm) [\#742](https://github.com/line/lbm-sdk/pull/742) fix to add error message in GetByteCode()
 
 ### Bug Fixes
 * (x/wasm) [\#453](https://github.com/line/lbm-sdk/pull/453) modify wasm grpc query api path
@@ -102,7 +103,7 @@ Ref: https://keepachangelog.com/en/1.0.0/
 * (x/token) [\#599](https://github.com/line/lbm-sdk/pull/599) fix the order of events
 * (x/wasm) [\#640](https://github.com/line/lbm-sdk/pull/640) remove legacy codes of wasm
 * (amino) [\#635](https://github.com/line/lbm-sdk/pull/635) change some minor things that haven't been fixed in #549
-* (store) [\#666](https://github.com/line/lbm-sdk/pull/666) change default `iavl-cache-size` and description 
+* (store) [\#666](https://github.com/line/lbm-sdk/pull/666) change default `iavl-cache-size` and description
 * (simapp) [\#679](https://github.com/line/lbm-sdk/pull/679) fix the bug not setting `iavl-cache-size` value of `app.toml`
 * (x/foundation) [\#687](https://github.com/line/lbm-sdk/pull/687) fix bugs on aborting x/foundation proposals
 * (global) [\#694](https://github.com/line/lbm-sdk/pull/694) replace deprecated functions since go 1.16 or 1.17

store/types/store.go

@@ -203,7 +203,7 @@ type CommitMultiStore interface {
 type KVStore interface {
 	Store
 
-	// Get returns nil iff key doesn't exist. Panics on nil key.
+	// Get returns nil if key doesn't exist. Panics on nil key.
 	Get(key []byte) []byte
 
 	// Has checks if a key exists. Panics on nil key.

x/wasm/keeper/keeper.go

@@ -876,7 +876,7 @@ func (k Keeper) GetByteCode(ctx sdk.Context, codeID uint64) ([]byte, error) {
 	var codeInfo types.CodeInfo
 	codeInfoBz := store.Get(types.GetCodeKey(codeID))
 	if codeInfoBz == nil {
-		return nil, nil
+		return nil, types.ErrNotFound
 	}
 	k.cdc.MustUnmarshal(codeInfoBz, &codeInfo)
 	return k.wasmVM.GetCode(codeInfo.CodeHash)

x/wasm/keeper/keeper_test.go

@@ -1928,3 +1928,40 @@ func TestIterateInactiveContracts(t *testing.T) {
 	expectList := []sdk.AccAddress{example1.Contract, example2.Contract}
 	assert.ElementsMatch(t, expectList, inactiveContracts)
 }
+
+func TestKeeper_GetByteCode(t *testing.T) {
+
+	ctx, keepers := CreateTestInput(t, false, SupportedFeatures, nil, nil)
+	keeper := keepers.ContractKeeper
+
+	deposit := sdk.NewCoins(sdk.NewInt64Coin("denom", 100000))
+	creator := keepers.Faucet.NewFundedAccount(ctx, deposit...)
+
+	em := sdk.NewEventManager()
+	_, err := keeper.Create(ctx.WithEventManager(em), creator, hackatomWasm, nil)
+	require.NoError(t, err)
+
+	tests := []struct {
+		name    string
+		codeID  uint64
+		want    []byte
+		wantErr bool
+		expErr  *sdkerrors.Error
+	}{
+		{name: "success", codeID: 1, want: hackatomWasm, wantErr: false, expErr: nil},
+		{name: "not found contract", codeID: 42, want: nil, wantErr: true, expErr: types.ErrNotFound},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got, err := keepers.WasmKeeper.GetByteCode(ctx, tt.codeID)
+			if tt.wantErr {
+				require.Equal(t, err, tt.expErr)
+				return
+			}
+			require.NoError(t, err)
+			require.Equal(t, tt.want, got)
+
+		})
+	}
+}