A convention-based object mapper that utilizes TypeScript decorators to simplify the mapping of objects between themselves.

Usage no npm install needed!

<script type="module">
  import mapperTs from '';



  • This package is a simple automapper where you can use decorators to map objects.


# importing modules
import { Mapper, AddMap, IgnoreMap } from 'mapper-ts/lib-esm';


Mapping properties in a class

class AClass {
  // Mapping a property by name
  prop1A: string;
  prop2A: number;

  constructor(prop1A: string, prop2A: number) {
    this.prop1A = prop1A;
    this.prop2A = prop2A;
class BClass {
  prop1B: string;
  prop2B: number;

  // Any properties that don't need to be mapped simply shouldn't have the @AddMap() decorator.
  unmappedProp1B: number;
  unmappedProp2B: string;

  // Mapping an object property by passing it's type
  propAClass: AClass;
// Any property name in @IgnoreMap() will be ignored from the source object if it exists in it
@IgnoreMap('ignoredObj', 'ignoredProp', 'nonexistantProp')
class CClass {
  prop1C: string;
  prop2C: number;

  // Also valid if an object's property name also needs to be mapped
  @AddMap(BClass, 'anyPropName')
  propBClass: BClass;

Calling the method

const unmappedA = { prop1B: 'PROP 1B', prop2B: 10 };

const unmappedB = {
  prop1A: 'PROP 1B',
  prop2A: 10,
  unmappedProp1B: 20,
  unmappedProp2B: 'UNMAPPED 2B',
  propAClass:  { prop1B: 'PROP 1B in A', prop2B: 300 };

const unmappedC = {
  prop1A: 'PROP 1A',
  prop2A: 20,
  anyPropName: {
    prop1A: 'PROP 1A in C',
    prop2A: 20,
    unmappedProp1B: 20,
    unmappedProp2B: 'UNMAPPED 2B in C',
  ignoredObj: {
    ignoredProp1: 'IGNORED PROP in obj',
    ignoredProp2: 'IGNORED PROP in obj2',
  ignoredProp: 'IGNORED PROP',

const mappedA = new Mapper(AClass).map(unmappedA);

const mappedB = new Mapper(BClass).map(unmappedB);

const mappedC = new Mapper(CClass).map(unmappedC);
# Results:
AClass { prop1A: 'PROP 1B', prop2A: 10 }
BClass {
  prop1B: 'PROP 1B',
  prop2B: 10,
  unmappedProp1B: 20,
  unmappedProp2B: 'UNMAPPED 2B',
  propAClass: AClass { prop1A: 'PROP 1B in A', prop2A: 300 }
CClass {
  prop1C: 'PROP 1A',
  prop2C: 20,
  propBClass: BClass {
    prop1B: 'PROP 1A in C',
    prop2B: 20,
    unmappedProp1B: 20,
    unmappedProp2B: 'UNMAPPED 2B in C',
    propAClass: null

Compiling the source code to JS files

  • To compile all the code in the src folder to the lib-esm folder, run this command at the root of the project with typescript installed:
  • All configuration for this command is already set in tsconfig.json