optional-deep-merge v1.0.1

optional-deep-merge

This package provides a utility type RecursivePartial<T> and a function optionalDeepMerge<T>(target: T, source: RecursivePartial<T>): T for performing a deep merge of objects with recursively optional properties.

The RecursivePartial<T> type allows you to make all properties of an object type T recursively optional.

The optionalDeepMerge function performs a deep merge of an object target of type T with an object source of type RecursivePartial<T>, and returns a new object of type T that contains all properties from both objects, with values from the source object taking precedence over the target object.

Usage

Creating optional properties

To make all properties of an object type T recursively optional, use the RecursivePartial<T> type:

import { RecursivePartial } from "optional-deep-merge";

interface Configuration {
  server: {
    host: string;
    port: number;
    ssl?: boolean;
  };
  database: {
    url: string;
    username: string;
    password: string;
  };
  logging: {
    enabled: boolean;
    level: 'debug' | 'info' | 'warn' | 'error';
  };
}

type PartialConfiguration = RecursivePartial<Configuration>;

Merging recursively partial objects

To merge an object with recursively optional properties (RecursivePartial<T>) back to the origin type, use the optionalDeepMerge function:

import { optionalDeepMerge } from "optional-deep-merge";

// Define default configuration
const defaultConfig: Configuration = {
  server: {
    host: 'localhost',
    port: 8080,
    ssl: false
  },
  database: {
    url: 'mongodb://localhost/mydb',
    username: 'myuser',
    password: 'mypassword'
  },
  logging: {
    enabled: true,
    level: 'info'
  }
};

// Define the configuration override
const customSettings: PartialConfiguration = {
  server: {
    port: 3000,
    ssl: true
  },
  database: {
    password: 'newpassword'
  },
  logging: {
    level: 'debug'
  }
};

const mergedConfig = optionalDeepMerge(defaultConfig, customSettings);

License

Distributed under the MIT License.

Please see the LICENSE for more information.