Merge pull request #2246 from CosmWasm/mergify/bp/releases/v0.6x/pr-2168

feat(data): Make sure Aliases in DenomUnit is not nil (backport #2168)

Author: chipshort

x/wasm/keeper/query_plugins.go

@@ -827,6 +827,10 @@ func ConvertSdkDenomUnitsToWasmDenomUnits(denomUnits []*banktypes.DenomUnit) []w
 			Exponent: u.Exponent,
 			Aliases:  u.Aliases,
 		}
+		// Returning nil may break cosmwasm-std
+		if u.Aliases == nil {
+			converted[i].Aliases = []string{}
+		}
 	}
 	return converted
 }

x/wasm/keeper/query_plugins_test.go

@@ -240,6 +240,7 @@ func TestBankQuerierMetadata(t *testing.T) {
 			{
 				Denom:    "utest",
 				Exponent: 0,
+				Aliases:  []string{},
 			},
 		},
 	}
@@ -269,6 +270,60 @@ func TestBankQuerierMetadata(t *testing.T) {
 			{
 				Denom:    "utest",
 				Exponent: 0,
+				Aliases:  []string{},
+			},
+		},
+	}
+	assert.Equal(t, exp, got.Metadata)
+
+	_, gotErr2 := q(ctx, &wasmvmtypes.BankQuery{
+		DenomMetadata: &wasmvmtypes.DenomMetadataQuery{
+			Denom: "uatom",
+		},
+	})
+	require.Error(t, gotErr2)
+	assert.Contains(t, gotErr2.Error(), "uatom: not found")
+}
+
+func TestBankQuerierMetadataWithNilAliases(t *testing.T) {
+	metadata := banktypes.Metadata{
+		Name: "Test Token",
+		Base: "utest",
+		DenomUnits: []*banktypes.DenomUnit{
+			{
+				Denom:    "utest",
+				Exponent: 0,
+				Aliases:  nil,
+			},
+		},
+	}
+
+	mock := bankKeeperMock{GetDenomMetadataFn: func(ctx context.Context, denom string) (banktypes.Metadata, bool) {
+		if denom == "utest" {
+			return metadata, true
+		} else {
+			return banktypes.Metadata{}, false
+		}
+	}}
+
+	ctx := sdk.Context{}
+	q := keeper.BankQuerier(mock)
+	gotBz, gotErr := q(ctx, &wasmvmtypes.BankQuery{
+		DenomMetadata: &wasmvmtypes.DenomMetadataQuery{
+			Denom: "utest",
+		},
+	})
+	require.NoError(t, gotErr)
+	var got wasmvmtypes.DenomMetadataResponse
+	require.NoError(t, json.Unmarshal(gotBz, &got))
+	exp := wasmvmtypes.DenomMetadata{
+		Name: "Test Token",
+		Base: "utest",
+		DenomUnits: []wasmvmtypes.DenomUnit{
+			{
+				Denom:    "utest",
+				Exponent: 0,
+				Aliases:  []string{},
 			},
 		},
 	}
@@ -292,6 +347,7 @@ func TestBankQuerierAllMetadata(t *testing.T) {
 				{
 					Denom:    "utest",
 					Exponent: 0,
+					Aliases:  []string{},
 				},
 			},
 		},
@@ -321,6 +377,7 @@ func TestBankQuerierAllMetadata(t *testing.T) {
 					{
 						Denom:    "utest",
 						Exponent: 0,
+						Aliases:  []string{},
 					},
 				},
 			},