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, '[email protected]')).then((data) => {
  console.log(data); // { name: 'guardian', age: 18, email: '[email protected]' }
});
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, '[email protected]')).then((data) => {
  console.log(data); // [ 'age: Invalid integer' ]
});
userService.create(new User('guardian', 19, '[email protected]')).then((data) => {
  console.log(data); // { name: 'guardian', age: 19, email: '[email protected]' }
});

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 [email protected]