guardian-x

A library for data rule validation.

Serve only

guardian-x is exclusively designed for server-side validation of the received data.

Installation and Usage

Server-side usage

Install the library with npm install guardian-x

Example code

Entity

import { IsEmail, IsNumber, IsOptional, IsString, Length, Size } from 'guardian-x';

class User {
  @Length({ min: 5, max: 8 })
  @IsString()
  name: string;
  @Size({ min: 18, max: 120 })
  @IsNumber()
  age: number;
  @IsOptional()
  @IsEmail()
  @IsString()
  email: string | null;

  constructor(name: string, age: number, email: string | null) {
    this.name = name;
    this.age = age;
    this.email = email;
  }
}

Service

import { GMethod, Guardian} from 'guardian-x';

class UserService {
  @GMethod()
  async create(@Guardian() user: User) {
    return user;
  }
}

const userService = new UserService();

userService.create(new User('guardian', 18, '[e-mail]')).then((data) => {
  console.log(data); // { name: 'guardian', age: 18, email: '[e-mail]' }
});
userService.create(new User('guardian', 18, 'example.com')).then((data) => {
  console.log(data); // [ 'email: Value is not comply with the email address rules.' ]
});
userService.create(new User('gua', 180, null)).then((data) => {
  console.log(data);
  /*
  [
    'name: Length must more than 5 and less than 8',
    'age: Size must more than 18 and less than 120'
  ]
  */
});

Rules

Standard

Here are some type restriction rules.

Rule	Type
IsNumber	number
IsString	string
IsBoolean	boolean
IsArray	array
IsObject	object

Here are some basic rules.

Note: Basic rules are additional restrictions on type restriction rules and cannot be used alone.

Rule	Type	Explain
IsOptional	any	Allow the value to be null or undefined.
Size	number	Restrict the size of the number type. { min?: number, max?: number } | number
IsIn	number	Validate whether the value exists in the specified set. number[]
IsAge	number	Validate whether the value matches the standard age.
Length	string	Restrict the length of the string type. { min?: number, max?: number } | number
IsEmail	string	Validate whether the value conforms to an email address.
IsPhone	string	Validate whether the value conforms to an phone number.
IsUrl	string	Validate whether the value conforms to an url.

Custom

Example Code

import { DataType, GMethod, Guardian, IsEmail, IsNumber, IsOptional, IsString, Length, Size, createDecMethod } from 'guardian-x';

// Custom DecMethod
const IsInteger = createDecMethod(DataType.NUMBER, (value: number) => {
  return Number.isInteger(value) ? null : 'Invalid integer';
})

// Entity
class User {
  @Length({ min: 5, max: 8 })
  @IsString()
  name: string;
  @IsInteger()
  @Size({ min: 18, max: 120 })
  @IsNumber()
  age: number;
  @IsOptional()
  @IsEmail()
  @IsString()
  email: string | null;

  constructor(name: string, age: number, email: string | null) {
    this.name = name;
    this.age = age;
    this.email = email;
  }
}

// Service
class UserService {
  @GMethod()
  async create(@Guardian() user: User) {
    return user;
  }
}

const userService = new UserService();

userService.create(new User('guardian', 18.5, '[e-mail]')).then((data) => {
  console.log(data); // [ 'age: Invalid integer' ]
});
userService.create(new User('guardian', 19, '[e-mail]')).then((data) => {
  console.log(data); // { name: 'guardian', age: 19, email: '[e-mail]' }
});

Options

Attribute	Type	Explain	Default
skipMissingProperties	boolean	Allow the value to be undefined.	false
buildMethod	(error: string[]) => any	Method for building a validated return object.	-

Example Code

const guardianOptions: IGuardianOptions = {
  skipMissingProperties: true,
  buildMethod: (error: string[]) => {
    return { msg: error };
  }
};
const GuardianMethod: MethodDecorator = GMethod(guardianOptions);

Epilogue

If you have any valuable suggestions, please contact email [e-mail]