Installation

Node

# Install with npm
npm install deepmerge-ts --save-dev

# Install with yarn
yarn add -D deepmerge-ts

Features

• Merged output has correct typing.
• Record merging support.
• Array merging support.
• Map and Set merging support.
• Customized merging.

Usage

Example using default config

import { deepmerge } from "deepmerge-ts";

const x = {
  record: {
    prop1: "value1",
    prop2: "value2",
  },
  array: [1, 2, 3],
  set: new Set([1, 2, 3]),
  map: new Map([
    ["key1", "value1"],
    ["key2", "value2"],
  ]),
};

const y = {
  record: {
    prop1: "changed",
    prop3: "value3",
  },
  array: [2, 3, 4],
  set: new Set([2, 3, 4]),
  map: new Map([
    ["key2", "changed"],
    ["key3", "value3"],
  ]),
};

const merged = deepmerge(x, y);

console.log(merged);

// Prettierfied output:
//
// {
//   record: {
//      prop1: "changed",
//      prop2: "value2",
//      prop3: "value3"
//   }
//   array: (6) [1, 2, 3, 2, 3, 4]
//   set: Set(4) {1, 2, 3, 4}
//   map: Map(3) {
//    "key1" => "value1",
//    "key2" => "changed",
//    "key3" => "value3"
//   }
// }

Using customized config

See deepmerge custom docs.

API

deepmerge(x, y, ...)

Merges the given inputs together using the default configuration.

deepmerge(...inputs)

Merges the array of inputs together using the default configuration.

Note: If inputs isn't typed as a tuple then we cannot determine the output type. The output type will simply be unknown.

deepmergeCustom(options)

Generate a customized deepmerge function using the given options. The returned function works just like deepmerge except it uses the customized configuration.

options

The following options can be used to customize the deepmerge function.
All these options are optional.

mergeRecords

Type: false | (values: Record<any, unknown>[], utils: DeepMergeMergeFunctionUtils) => unknown

If false, records won't be merged. If set to a function, that function will be used to merge records.

Note: Records are "vanilla" objects (e.g. { foo: "hello", bar: "world" }).

mergeArrays

Type: false | (values: unknown[][], utils: DeepMergeMergeFunctionUtils) => unknown

If false, arrays won't be merged. If set to a function, that function will be used to merge arrays.

mergeMaps

Type: false | (values: Map<unknown, unknown>[], utils: DeepMergeMergeFunctionUtils) => unknown

If false, maps won't be merged. If set to a function, that function will be used to merge maps.

mergeSets

Type: false | (values: Set<unknown>[], utils: DeepMergeMergeFunctionUtils) => unknown

If false, sets won't be merged. If set to a function, that function will be used to merge sets.

mergeOthers

Type: (values: Set<unknown>[], utils: DeepMergeMergeFunctionUtils) => unknown

If set to a function, that function will be used to merge everything else.

Note: This includes merging mixed types, such as merging a map with an array.

DeepMergeMergeFunctionUtils

This is a set of utility functions that are made available to your custom merge functions.

mergeFunctions

These are all the merge function being used to perform the deepmerge.
These will be the custom merge functions you gave, or the default merge functions for options you didn't customize.

defaultMergeFunctions

These are all the merge functions that the default, non-customize deepmerge function uses.

deepmerge

This is your top level customized deepmerge function.

Note: Be careful when calling this as it is really easy to end up in an infinite loop.