package survey import ( "errors" "fmt" "reflect" "github.com/AlecAivazis/survey/v2/core" ) // Required does not allow an empty value func Required(val interface{}) error { // the reflect value of the result value := reflect.ValueOf(val) // if the value passed in is the zero value of the appropriate type if isZero(value) && value.Kind() != reflect.Bool { return errors.New("Value is required") } return nil } // MaxLength requires that the string is no longer than the specified value func MaxLength(length int) Validator { // return a validator that checks the length of the string return func(val interface{}) error { if str, ok := val.(string); ok { // if the string is longer than the given value if len([]rune(str)) > length { // yell loudly return fmt.Errorf("value is too long. Max length is %v", length) } } else { // otherwise we cannot convert the value into a string and cannot enforce length return fmt.Errorf("cannot enforce length on response of type %v", reflect.TypeOf(val).Name()) } // the input is fine return nil } } // MinLength requires that the string is longer or equal in length to the specified value func MinLength(length int) Validator { // return a validator that checks the length of the string return func(val interface{}) error { if str, ok := val.(string); ok { // if the string is shorter than the given value if len([]rune(str)) < length { // yell loudly return fmt.Errorf("value is too short. Min length is %v", length) } } else { // otherwise we cannot convert the value into a string and cannot enforce length return fmt.Errorf("cannot enforce length on response of type %v", reflect.TypeOf(val).Name()) } // the input is fine return nil } } // MaxItems requires that the list is no longer than the specified value func MaxItems(numberItems int) Validator { // return a validator that checks the length of the list return func(val interface{}) error { if list, ok := val.([]core.OptionAnswer); ok { // if the list is longer than the given value if len(list) > numberItems { // yell loudly return fmt.Errorf("value is too long. Max items is %v", numberItems) } } else { // otherwise we cannot convert the value into a list of answer and cannot enforce length return fmt.Errorf("cannot impose the length on something other than a list of answers") } // the input is fine return nil } } // MinItems requires that the list is longer or equal in length to the specified value func MinItems(numberItems int) Validator { // return a validator that checks the length of the list return func(val interface{}) error { if list, ok := val.([]core.OptionAnswer); ok { // if the list is shorter than the given value if len(list) < numberItems { // yell loudly return fmt.Errorf("value is too long. Min items is %v", numberItems) } } else { // otherwise we cannot convert the value into a list of answer and cannot enforce length return fmt.Errorf("cannot impose the length on something other than a list of answers") } // the input is fine return nil } } // ComposeValidators is a variadic function used to create one validator from many. func ComposeValidators(validators ...Validator) Validator { // return a validator that calls each one sequentially return func(val interface{}) error { // execute each validator for _, validator := range validators { // if the answer's value is not valid if err := validator(val); err != nil { // return the error return err } } // we passed all validators, the answer is valid return nil } } // isZero returns true if the passed value is the zero object func isZero(v reflect.Value) bool { switch v.Kind() { case reflect.Slice, reflect.Map: return v.Len() == 0 } // compare the types directly with more general coverage return reflect.DeepEqual(v.Interface(), reflect.Zero(v.Type()).Interface()) }