Add type slice (only for strings) type (#176)

pkg/config/config.go

@@ -94,6 +94,18 @@ func DefineConfiguration(
 			}
 			mainCMD.PersistentFlags().
 				StringP(field.FieldName, field.CLIShortHand, value, field.GetDescription())
+		case reflect.Slice:
+			value, err := field.StringArray()
+			if err != nil {
+				return nil, nil, fmt.Errorf(
+					"field %s, %s: %w",
+					field.FieldName,
+					field.FieldType,
+					err,
+				)
+			}
+			mainCMD.PersistentFlags().
+				StringArrayP(field.FieldName, field.CLIShortHand, value, field.GetDescription())
 		default:
 			return nil, nil, fmt.Errorf(
 				"field %s, %s is not yet supported",

pkg/field/fields.go

@@ -51,6 +51,16 @@ func (s SchemaField) String() (string, error) {
 	return value, nil
 }
 
+// StringArray retuns the default value as a string array.
+func (s SchemaField) StringArray() ([]string, error) {
+	value, ok := s.DefaultValue.([]string)
+	if !ok {
+		return nil, WrongValueTypeErr
+	}
+
+	return value, nil
+}
+
 func (s SchemaField) GetDescription() string {
 	var line string
 	if s.Description == "" {
@@ -120,6 +130,20 @@ func IntField(name string, optional ...fieldOption) SchemaField {
 	return field
 }
 
+func StringArrayField(name string, optional ...fieldOption) SchemaField {
+	field := SchemaField{
+		FieldName:    name,
+		FieldType:    reflect.Slice,
+		DefaultValue: []string{},
+	}
+
+	for _, o := range optional {
+		field = o(field)
+	}
+
+	return field
+}
+
 func toUpperCase(i string) string {
 	return strings.ReplaceAll(strings.ToUpper(i), "-", "_")
 }