GoValidator

GoValidator is a data validation package that can sanitize and validate your data to ensure its safety and integrity as much as possible. GoValidator will not use struct tags as validation and there is no need of them.

Our goal is to avoid using any type assertion or reflection for simplicity. We would be delighted if you were interested in helping us improve the GoValidator package. Feel free to make your pull request.

Getting Started

Go Validator includes a set of validation rules and a handy CustomRule() method to define any custom rule.

Installation

Run the following command to install the package:

go get github.com/rezakhademix/govalidator/v2

Import

Import package in your code-base by using:

import validator "github.com/rezakhademix/govalidator/v2"

Documentation

GoValidator package has the following features and method to use. Each validation rule in GoValidator has it's own default message, e.g: required rule for a required name has the default message of: name is required but you can define your custom field name and message.

Methods (also known as validation rules)

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Method	Description
RequiredInt	RequiredInt checks if an integer value is provided or not.
RequiredFloat	RequiredFloat checks if a float value is provided or not.
RequiredString	RequiredString checks if a string value is empty or not.
RequiredSlice	RequiredSlice checks if a slice has any value or not.
BetweenInt	BetweenInt checks whether value falls within the specified range or not.
BetweenFloat	BetweenFloat checks whether value falls within the specified range or not.
Date	Date checks value to be a valid, non-relative date.
Email	Email checks value to match EmailRegex regular expression.
Exists	Exists checks given value exists in given table or not.
NotExists	NotExists checks given value doesn't exist in given table, except.
ExistsExceptSelf	ExistsExceptSelf checks given value exists in a specified column of a table, excluding a row identified by selfID
LenString	LenString checks length of given string is equal to given size or not.
LenInt	LenInt checks length of given integer is equal to given size or not.
LenSlice	LenSlice checks length of given slice is equal to given size or not.
MaxInt	MaxInt checks given integer is less than or equal given max value.
MaxFloat	MaxFloat checks given float is less than or equal given max value.
MaxString	MaxString checks length of given string is less than or equal given max value.
MinInt	MinInt checks given integer is greater than or equal given min value.
MinFloat	MinFloat checks given float is greater than or equal given min value.
MinString	MinString checks length of given string is greater than or equal given min value.
RegexMatches	RegexMatches checks given string matches given regular expression pattern.
UUID	UUID checks given value is a valid universally unique identifier (UUID).
When	When will execute given closure if given condition is true.
URL	URL will check given string is a valid URL or not.
Before	Before will check if given time instant t is before given time instant u.
After	After will check if given time instant t is after given time instant u.
IP4	IP4 will check whether given string is a valid IPV4.
DefaultInt	DefaultInt sets a default value for any pointer to an int that is passed.
DefaultFloat	DefaultFloat sets a default value for any pointer to a float that is passed.
DefaultString	DefaultString sets a default value for any pointer to a string that is passed.
IsJSON	IsJSON will check if given string is a valid JSON.
NumericString	NumericString will check if given value is a valid string of numbers.
MAC	MAC will check if given value is a valid MAC address.
CustomRule	CustomRule is a dynamic method to define any custom validation rule.

Functions (other common validation rules)

---

Method	Description
In	In checks given value is included in the provided list of values.
Unique	Unique checks whether values in the provided slice are unique.

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Examples:

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1. Simple usage:

       type User struct {
           Name string `json:"name"`
           Age unit    `json:"age"`
       }
   
       var user User
       _ := c.Bind(&user)  // error ignored for simplicity
   
       v := govalidator.New() // be sure to import govalidator/v2
   
       v.RequiredInt(user.Age, "age", "").         // age can not be null or 0
           MinInt(user.Age, 18, "age", "")         // minimum value for age is 18
   
       v.RequiredString(user.Name, "name", "")     // name can not be null, "" or " "
           MaxString(user.Name, 50, "name", "")    // maximum acceptable length for name field is 50
   
       if v.IsFailed() {
           return v.Errors()  // will return failed validation error messages
       }

2. With custom field names and messages:

       type User struct {
           Name string `json:"name"`
       }
   
       var user User
       _ := c.ShouldBind(&user)  // error ignored for simplicity
   
       v := govalidator.New()
   
       v.MaxString(user.Name, "first_name", "please fill first_name field") // with custom field name and custom validation error message
   
       if v.IsFailed() {
           return v.Errors()
        }

3. Advanced usage with any custom validation rule: You can define any custom rules or any flexible rule that does not exist in default govalidator package. Simply use CustomRule() method to define your desired data validations:

       type Profile struct {
           Name   string
           Age    int
           Score  int
           Status []string
       }
   
       var profile Profile
   
       // after filling profile struct with binding or other methods
   
       v := govalidator.New()
   
       v.CustomRule(profile.Name != "", "name", "name is required")  // CustomRule is a method to define a custom rule as first parameter and then pass field name and validation error message
   
       v.CustomRule(profile.Age > 18, "age", "age must be greater than 18")
   
       // we just need to pass a bool as a rule
       // `checkScore()` is your custom method that returns a bool and can be used as a rule
       v.CustomRule(checkScore(), "score", "score must")
   
       // using `In` Generic rule:
       statuses := []string{"active", "inactive", "pending"}
   
       v.CustomRule(validator.In[ProfileStatuses](profile.Status, statuses), "status", "status must be in:...")
   
       if v.IsFailed() {
           return v.Errors()
       }

4. Deep Dive:

       type CategoryCreateReq struct {
           ParentID    *int   `json:"parent_id"`
           Name        string `json:"name"`
           Description string `json:"description"`
           Status      int    `json:"status"`
           Meta        string `json:"meta"`
       }
   
   
       var categoryCreateReq CategoryCreateReq
   
       // after filling CategoryCreateReq struct with binding or other methods
   
       v := govalidator.New().WithRepo(validatorRepo)  // be sure to import govalidator/v2
   	    
   	ok := v.
   		RequiredString(req.Name, "name", msgCategoryNameRequired).
   		MaxString(req.Name, nameMaxLength, "name", msgCategoryNameMaxLength).
   		MinString(req.Name, nameMinLength, "name", msgCategoryNameMinLength).
   		NotExists(req.Name, "categories", "name", "name", msgCategoryNameAlreadyExists). // ensure the value of req.Name does not exist in the "name" column of the "categories" table in the database
   	  	MaxString(req.Description, descriptionMaxLength, "description", msgDescriptionMaxLength).
   	  	MinInt(req.Status, minStatus, "status", msgMinCategoryStatusIsWrong).
   	  	MaxInt(req.Status, maxStatus, "status", msgMaxCategoryStatusIsWrong).
   		IsJSON(req.Meta, "meta", msgMetaMustBeJSON).
   	  	When(req.ParentID != nil, func() {  
               		v.Exists(*req.ParentID, "categories", "id", "parent_id", msgCategoryParentIDNotExist)   // checks if the value of req.ParentID exists in the "id" column of the "categories" table in the database
   		}).
   	  	IsPassed()
   
       if !ok {
         return v.Errors()
       }

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Benchmarks

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TBD