package constants type PlanType string const ( PlanBasic PlanType = "basic" PlanPremium PlanType = "premium" PlanEnterprise PlanType = "enterprise" ) func GetAllPlanTypes() []PlanType { return []PlanType{ PlanBasic, PlanPremium, PlanEnterprise, } } func IsValidPlanType(planType PlanType) bool { for _, validType := range GetAllPlanTypes() { if planType == validType { return true } } return false }