Address review comments

x/auth/ante/sigverify.go

@@ -512,6 +512,6 @@ func signatureDataToBz(data signing.SignatureData) ([][]byte, error) {
 
 		return sigs, nil
 	default:
-		return nil, fmt.Errorf("unexpected signature data type %T", data)
+		return nil, sdkerrors.ErrInvalidType.Wrapf("unexpected signature data type %T", data)
 	}
 }

x/auth/client/cli/query.go

@@ -10,6 +10,7 @@ import (
 	"github.com/cosmos/cosmos-sdk/client"
 	"github.com/cosmos/cosmos-sdk/client/flags"
 	sdk "github.com/cosmos/cosmos-sdk/types"
+	"github.com/cosmos/cosmos-sdk/types/errors"
 	"github.com/cosmos/cosmos-sdk/types/query"
 	"github.com/cosmos/cosmos-sdk/version"
 	authtx "github.com/cosmos/cosmos-sdk/x/auth/tx"
@@ -222,9 +223,10 @@ Example:
 $ %s query tx <hash>
 $ %s query tx --%s=%s <addr>:<sequence>
 $ %s query tx --%s=%s <sig1_base64,sig2_base64...>
-`, version.AppName, 
-version.AppName, flagType, typeAccSeq, 
-version.AppName, flagType, typeSig)),
+`,
+			version.AppName,
+			version.AppName, flagType, typeAccSeq,
+			version.AppName, flagType, typeSig)),
 		Args: cobra.ExactArgs(1),
 		RunE: func(cmd *cobra.Command, args []string) error {
 			clientCtx, err := client.GetClientQueryContext(cmd)
@@ -255,11 +257,10 @@ version.AppName, flagType, typeSig)),
 				}
 			case typeSig:
 				{
-					if len(args) != 1 || args[0] == "" {
-						return fmt.Errorf("argument should be comma-separated signatures")
+					sigParts, err := parseSigArgs(args)
+					if err != nil {
+						return err
 					}
-
-					sigParts := strings.Split(args[0], ",")
 					tmEvents := make([]string, len(sigParts))
 					for i, sig := range sigParts {
 						tmEvents[i] = fmt.Sprintf("%s.%s='%s'", sdk.EventTypeTx, sdk.AttributeKeySignature, sig)
@@ -313,3 +314,12 @@ version.AppName, flagType, typeSig)),
 
 	return cmd
 }
+
+// parseSigArgs parses comma-separated signatures from the CLI arguments.
+func parseSigArgs(args []string) ([]string, error) {
+	if len(args) != 1 || args[0] == "" {
+		return nil, fmt.Errorf("argument should be comma-separated signatures")
+	}
+
+	return strings.Split(args[0], ","), nil
+}

x/auth/client/cli/query_test.go

@@ -0,0 +1,32 @@
+package cli
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestParseSigs(t *testing.T) {
+	cases := []struct {
+		name       string
+		args       []string
+		expErr     bool
+		expNumSigs int
+	}{
+		{"no args", []string{}, true, 0},
+		{"empty args", []string{""}, true, 0},
+		{"too many args", []string{"foo", "bar"}, true, 0},
+		{"1 sig", []string{"foo"}, false, 1},
+		{"3 sigs", []string{"foo,bar,baz"}, false, 3},
+	}
+
+	for _, tc := range cases {
+		sigs, err := parseSigArgs(tc.args)
+		if tc.expErr {
+			require.Error(t, err)
+		} else {
+			require.NoError(t, err)
+			require.Equal(t, tc.expNumSigs, len(sigs))
+		}
+	}
+}