accounts/abi: multiple fixes to arguments

accounts/abi/argument.go

@@ -92,9 +92,8 @@ func (arguments Arguments) Unpack(v interface{}, data []byte) error {
 	if len(data) == 0 {
 		if len(arguments) != 0 {
 			return fmt.Errorf("abi: attempting to unmarshall an empty string while arguments are expected")
-		} else {
-			return nil // Nothing to unmarshal, return
 		}
+		return nil // Nothing to unmarshal, return
 	}
 	// make sure the passed value is arguments pointer
 	if reflect.Ptr != reflect.ValueOf(v).Kind() {
@@ -115,18 +114,24 @@ func (arguments Arguments) Unpack(v interface{}, data []byte) error {
 
 // UnpackIntoMap performs the operation hexdata -> mapping of argument name to argument value
 func (arguments Arguments) UnpackIntoMap(v map[string]interface{}, data []byte) error {
+	// Make sure map is not nil
+	if v == nil {
+		return fmt.Errorf("abi: cannot unpack into a nil map")
+	}
 	if len(data) == 0 {
 		if len(arguments) != 0 {
 			return fmt.Errorf("abi: attempting to unmarshall an empty string while arguments are expected")
-		} else {
-			return nil // Nothing to unmarshal, return
 		}
+		return nil // Nothing to unmarshal, return
 	}
 	marshalledValues, err := arguments.UnpackValues(data)
 	if err != nil {
 		return err
 	}
-	return arguments.unpackIntoMap(v, marshalledValues)
+	for i, arg := range arguments.NonIndexed() {
+		v[arg.Name] = marshalledValues[i]
+	}
+	return nil
 }
 
 // unpack sets the unmarshalled value to go format.
@@ -198,19 +203,6 @@ func unpack(t *Type, dst interface{}, src interface{}) error {
 	return nil
 }
 
-// unpackIntoMap unpacks marshalledValues into the provided map[string]interface{}
-func (arguments Arguments) unpackIntoMap(v map[string]interface{}, marshalledValues []interface{}) error {
-	// Make sure map is not nil
-	if v == nil {
-		return fmt.Errorf("abi: cannot unpack into a nil map")
-	}
-
-	for i, arg := range arguments.NonIndexed() {
-		v[arg.Name] = marshalledValues[i]
-	}
-	return nil
-}
-
 // unpackAtomic unpacks ( hexdata -> go ) a single value
 func (arguments Arguments) unpackAtomic(v interface{}, marshalledValues interface{}) error {
 	if arguments.LengthNonIndexed() == 0 {
@@ -236,30 +228,28 @@ func (arguments Arguments) unpackAtomic(v interface{}, marshalledValues interfac
 // unpackTuple unpacks ( hexdata -> go ) a batch of values.
 func (arguments Arguments) unpackTuple(v interface{}, marshalledValues []interface{}) error {
 	var (
-		value = reflect.ValueOf(v).Elem()
-		typ   = value.Type()
-		kind  = value.Kind()
+		value          = reflect.ValueOf(v).Elem()
+		typ            = value.Type()
+		kind           = value.Kind()
+		nonIndexedArgs = arguments.NonIndexed()
 	)
-	if err := requireUnpackKind(value, typ, kind, arguments); err != nil {
+	if err := requireUnpackKind(value, len(nonIndexedArgs), arguments); err != nil {
 		return err
 	}
 
 	// If the interface is a struct, get of abi->struct_field mapping
 	var abi2struct map[string]string
 	if kind == reflect.Struct {
-		var (
-			argNames []string
-			err      error
-		)
-		for _, arg := range arguments.NonIndexed() {
-			argNames = append(argNames, arg.Name)
+		argNames := make([]string, len(nonIndexedArgs))
+		for i, arg := range nonIndexedArgs {
+			argNames[i] = arg.Name
 		}
-		abi2struct, err = mapArgNamesToStructFields(argNames, value)
-		if err != nil {
+		var err error
+		if abi2struct, err = mapArgNamesToStructFields(argNames, value); err != nil {
 			return err
 		}
 	}
-	for i, arg := range arguments.NonIndexed() {
+	for i, arg := range nonIndexedArgs {
 		switch kind {
 		case reflect.Struct:
 			field := value.FieldByName(abi2struct[arg.Name])

accounts/abi/reflect.go

@@ -118,18 +118,16 @@ func requireAssignable(dst, src reflect.Value) error {
 }
 
 // requireUnpackKind verifies preconditions for unpacking `args` into `kind`
-func requireUnpackKind(v reflect.Value, t reflect.Type, k reflect.Kind,
-	args Arguments) error {
-
-	switch k {
+func requireUnpackKind(v reflect.Value, minLength int, args Arguments) error {
+	switch v.Kind() {
 	case reflect.Struct:
 	case reflect.Slice, reflect.Array:
-		if minLen := args.LengthNonIndexed(); v.Len() < minLen {
+		if v.Len() < minLength {
 			return fmt.Errorf("abi: insufficient number of elements in the list/array for unpack, want %d, got %d",
-				minLen, v.Len())
+				minLength, v.Len())
 		}
 	default:
-		return fmt.Errorf("abi: cannot unmarshal tuple into %v", t)
+		return fmt.Errorf("abi: cannot unmarshal tuple into %v", v.Type())
 	}
 	return nil
 }
@@ -156,9 +154,8 @@ func mapArgNamesToStructFields(argNames []string, value reflect.Value) (map[stri
 			continue
 		}
 		// skip fields that have no abi:"" tag.
-		var ok bool
-		var tagName string
-		if tagName, ok = typ.Field(i).Tag.Lookup("abi"); !ok {
+		tagName, ok := typ.Field(i).Tag.Lookup("abi")
+		if !ok {
 			continue
 		}
 		// check if tag is empty.