Install

npm i @dsbasko/merge-and-map

or

yarn add @dsbasko/merge-and-map

Usage

The function mergeAndMap takes four arguments:

arr1: an array of objects that need to be merged with objects from arr2.

arr2: an array of objects to merge with objects from arr1.

fields: an array of two keys that indicate which fields in the objects from arr1 and arr2 should be used for merging.

tpl: a function that takes two arguments (an object from arr1 and an object from arr2) and returns a new object that will be added to the resulting array. If the tpl function returns null, the object will not be added to the resulting array.

The mergeAndMap function merges objects from the arr1 and arr2 arrays, using the values of the fields[0] and fields[1] fields as keys. If an object with the specified key is found in the arr2 array, the tpl function is called with two arguments (an object from arr1 and an object from arr2), and the result is added to the resulting array. If the object is not found or the tpl function returns undefined, the object is not added to the resulting array.

Example

import { mergeAndMap } from '@dsbasko/merge-and-map';

const users = [
  { id: 1, name: 'John' },
  { id: 2, name: 'Alice' },
  { id: 3, name: 'Bob' },
];

const info = [
  { userId: 1, address: '123 Main St' },
  { userId: 2, address: '456 Elm St' },
];

const result = mergeAndMap(users, info, ['id', 'userId'], (user, info) => ({
  ...user,
  address: info.address,
}));

console.log(result);
/*
[
  { id: 1, name: 'John', address: '123 Main St' },
  { id: 2, name: 'Alice', address: '456 Elm St' },
]
*/

In the example, we merge the users and info arrays using the id and userId fields. The tpl function merges objects by adding the address field to objects from users if the corresponding object is found in info. The result of the mergeAndMap function is an array of objects containing merged objects from users and info.

Author

Dmitriy Basenko [email protected], GitHub, Twitter, Telegram