Package Exports

@d3vtool/automapper
@d3vtool/automapper/dist/cjs/index.js

This package does not declare an exports field, so the exports above have been automatically detected and optimized by JSPM instead. If any package subpath is missing, it is recommended to post an issue to the original package (@d3vtool/automapper) to support the "exports" field. If that is not possible, create a JSPM override to customize the exports field for this package.

Readme

🔄 AutoMapper Utility

AutoMapper is a lightweight TypeScript utility designed to automate the transformation of objects between DTOs and Entities. It provides an easy way to map data between classes, ensuring that your data transformation code is cleaner and more maintainable.

It also includes a JsonObject base class for easy conversion of class instances to/from JSON.

📦 Installation

Install via your preferred package manager:

npm

npm install @d3vtool/automapper

yarn

yarn add @d3vtool/automapper

✅ Testing

To run the tests:

npm run test

✨ Features

Automatic mapping of fields between objects with matching names.
Explicit mapping support for different field names using forMember().
Allows multiple mapping configurations (e.g., User to UserDto and UserDto to User).
JSON serialization and deserialization using the JsonObject base class.

🧪 Examples

🔹 JsonObject Usage

1. Convert JSON to Entity

import { JsonObject } from "@d3vtool/automapper";

class User extends JsonObject<User> {
  constructor(
    public id?: string,
    public name?: string,
    public email?: string,
    public password?: string
  ) {
    super();
  }
}

const user = new User();
user.fromJson({
  id: "12",
  name: "Alice",
  email: "alice@mail.com",
  password: "secure123"
});

console.log(user.name); // "Alice"

2. Convert Entity to JSON

const user = new User("12", "Alice", "alice@mail.com", "secure123");
const json = user.toJson();

console.log(json);
// { id: '12', name: 'Alice', email: 'alice@mail.com', password: 'secure123' }

🔹 AutoMapper Usage

1. Create `autoMapper` instance

To create and reuse the AutoMapper instance:

import { AutoMapper } from "@d3vtool/automapper";

// Create one instance and reuse it across your application.
export const autoMapper = new AutoMapper();

2. Map with Matching Field Names (One Direction)

import { autoMapper } from "./somefile";
import { JsonObject } from "@d3vtool/automapper";

class User extends JsonObject<User> {
  constructor(
    public id?: string,
    public name?: string,
    public email?: string,
    public password?: string
  ) {
    super();
  }
}

class UserDto extends JsonObject<UserDto> {
  constructor(
    public id?: string,
    public name?: string,
    public email?: string
  ) {
    super();
  }
}

const userToDtoMapper = autoMapper.map(User, UserDto);

const user = new User("12", "Alice", "alice@mail.com", "secure123");
const userDto = userToDtoMapper.map(user);

console.log(userDto);
// Output: UserDto { id: '12', name: 'Alice', email: 'alice@mail.com' }

3. Custom Mapping with Different Field Names

class User extends JsonObject<User> {
  constructor(
    public id?: string,
    public firstName?: string,
    public lastName?: string,
    public email?: string,
    public password?: string
  ) {
    super();
  }
}

class UserDto extends JsonObject<UserDto> {
  constructor(
    public id?: string,
    public fullName?: string,
    public email?: string
  ) {
    super();
  }
}

const userToDtoMapper = autoMapper.map(User, UserDto);

// Custom mapping for `fullName` (combining `firstName` + `lastName`)
userToDtoMapper.forMember("fullName", (user) => `${user.firstName} ${user.lastName}`);

const user = new User("12", "Alice", "Smith", "alice@mail.com", "secure123");
const userDto = userToDtoMapper.map(user);

console.log(userDto);
// Output: UserDto { id: '12', fullName: 'Alice Smith', email: 'alice@mail.com' }

4. Explicit Reverse Mapping (UserDto to User)

To map in the reverse direction, you must explicitly create a new mapping:

const dtoToUserMapper = autoMapper.map(UserDto, User);

// Assuming userDto is an instance of UserDto and fields are same of entity and dto.
const userFromDto = dtoToUserMapper.map(userDto);

// If fields aren't same then:
dtoToUserMapper
    .forMember("firstName", (dto) => dto.fullName?.split(" ")[0])
    .forMember("lastName", (dto) => dto.fullName?.split(" ")[1]);

const userFromDto = dtoToUserMapper.map(userDto);

console.log(userFromDto);
// Output: User { id: '12', firstName: 'Alice', lastName: 'Smith', email: 'alice@mail.com', password: 'secure123' }

This package is open-source and licensed under the MIT License.

@d3vtool/automapper