gofiber/fiber · error

betweenLen constraint requires two arguments

Error message

betweenLen constraint requires two arguments

What it means

Error "betweenLen constraint requires two arguments" thrown in gofiber/fiber.

Source

Thrown at constraint.go:415

func (lenConstraintType) Execute(param string, data []any) bool {
	if len(data) == 0 {
		return false
	}
	limit, ok := data[0].(int)
	if !ok {
		return false
	}
	return len(param) == limit
}

type betweenLenConstraintType struct{}

func (betweenLenConstraintType) Name() string { return ConstraintBetweenLen }
func (betweenLenConstraintType) Analyze(args []string) ([]any, error) {
	args = parseConstraintArgs(args)
	if len(args) < 2 {
		return nil, errors.New("betweenLen constraint requires two arguments")
	}
	lo, err := strconv.Atoi(args[0])
	if err != nil {
		return nil, fmt.Errorf("parse constraint arg: %w", err)
	}
	hi, err := strconv.Atoi(args[1])
	if err != nil {
		return nil, fmt.Errorf("parse constraint arg: %w", err)
	}
	return []any{lo, hi}, nil
}

func (betweenLenConstraintType) Execute(param string, data []any) bool {
	if len(data) < 2 {
		return false
	}
	lo, ok := data[0].(int)
	if !ok {

View on GitHub (pinned to 9a4c7e57fe)

When it happens

Trigger: Thrown at constraint.go:415 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of gofiber/fiber@9a4c7e57fe (2026-08-04). Data as JSON: /data/errors/28862ae087d78040.json. Report an issue: GitHub.