@snailicide/build-config / utilities / PartialDeep

PartialDeep<T, Options>

type PartialDeep<T, Options> = _PartialDeep<T, ApplyDefaultOptions<PartialDeepOptions, DefaultPartialDeepOptions, Options>>;

Defined in: node_modules/.pnpm/type-fest@4.41.0/node_modules/type-fest/source/partial-deep.d.ts:96

Create a type from another type with all keys and nested keys set to optional.

Use-cases:

• Merging a default settings/config object with another object, the second object would be a deep partial of the default object.
• Mocking and testing complex entities, where populating an entire object with its keys would be redundant in terms of the mock or test.

Type Parameters

Type Parameter	Default type
T	-
Options extends PartialDeepOptions	{ }

Example

import type {PartialDeep} from 'type-fest';

const settings: Settings = {
	textEditor: {
		fontSize: 14,
		fontColor: '#000000',
		fontWeight: 400
	},
	autocomplete: false,
	autosave: true
};

const applySavedSettings = (savedSettings: PartialDeep<Settings>) => {
	return {...settings, ...savedSettings};
}

settings = applySavedSettings({textEditor: {fontWeight: 500}});

By default, this does not affect elements in array and tuple types. You can change this by passing {recurseIntoArrays: true} as the second type argument:

import type {PartialDeep} from 'type-fest';

type Settings = {
	languages: string[];
}

const partialSettings: PartialDeep<Settings, {recurseIntoArrays: true}> = {
	languages: [undefined]
};

See

PartialDeepOptions