defaults

What is defaults?

The `defaults` npm package is primarily used for merging a set of default properties with user-provided options. It is particularly useful in situations where you want to ensure that an object contains a certain set of properties with default values, even if some of those properties are not provided by the user. This can be very handy in configuration objects for libraries, APIs, or any other modular pieces of code that require a predictable structure of input options.

What are defaults's main functionalities?

Merging default options with user options

This feature allows the merging of a user-provided options object with a default options object. If the user provides a value for a given property, that value is used; otherwise, the default value is applied. This is particularly useful for configuring applications or modules where certain parameters are optional but should have a defined default behavior.

{"const defaults = require('defaults');\nconst userOptions = { color: 'blue' };\nconst defaultOptions = { color: 'red', size: 'large' };\nconst options = defaults(userOptions, defaultOptions);\nconsole.log(options); // Output: { color: 'blue', size: 'large' }"}

Other packages similar to defaults

lodash.merge

Lodash's `merge` function offers deep merging capabilities, which can be more comprehensive than the shallow merge provided by `defaults`. It allows for the merging of nested properties, which is useful when dealing with complex object structures. However, for simple use cases, `defaults` might be more straightforward and lightweight.

deep-extend

Similar to `lodash.merge`, `deep-extend` provides deep merging functionality. It is designed to recursively merge properties of objects, making it suitable for complex configurations. Compared to `defaults`, `deep-extend` offers a more robust solution for nested properties but might be overkill for simple scenarios.

README

defaults

Easily handle defaults for your options

Install

npm install defaults

Usage

import defaults from 'defaults';

const calculate = options => {
	options = defaults(options, {
		timeout: {
			before: 100,
			after: 100
		}
	});

	console.log(options);
	//=> {timeout: {before: 200, after: 100}}

	// …
}

// …

calculate({timeout: {before: 200}});

API

defaults(options, defaultOptions?)

Deeply merges the given options with the specified defaults and returns a new object.

The given parameters are deep-cloned and never mutated.

options

Type: object

The user-provided options.

If the value is not a plain object, a new plain object will be used instead.

defaultOptions

Type: object | undefined

The default options to use when a value is not provided in the options object.

FAQ

Why use this over object-spread?

• Does not overwrite options if they are not defined in the options object
• Supports deep merging of objects
• Provides protection against prototype pollution attacks