import { type PartialDeep } from "https://deno.land/x/actionify@0.3.0/src/deps/types.ts";
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.
Examples
Example 1
Example 1
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 also affects array and tuple types:
import type {PartialDeep} from 'type-fest';
interface Settings {
languages: string[];
}
const partialSettings: PartialDeep<Settings> = {
languages: [undefined]
};
If this is undesirable, you can pass {recurseIntoArrays: false} as the second type argument.
Type Parameters
optional
Options extends PartialDeepOptions = { }definition: T extends BuiltIns ? T : T extends Map<infer KeyType, infer ValueType> ? PartialMapDeep<KeyType, ValueType, Options> : T extends Set<infer ItemType> ? PartialSetDeep<ItemType, Options> : T extends ReadonlyMap<infer KeyType, infer ValueType> ? PartialReadonlyMapDeep<KeyType, ValueType, Options> : T extends ReadonlySet<infer ItemType> ? PartialReadonlySetDeep<ItemType, Options> : T extends ((...arguments: any[]) => unknown) ? T | undefined : T extends object ? T extends ReadonlyArray<infer ItemType> ? Options["recurseIntoArrays"] extends false ? T : ItemType[] extends T ? readonly ItemType[] extends T ? ReadonlyArray<PartialDeep<ItemType | undefined, Options>> : Array<PartialDeep<ItemType | undefined, Options>> : PartialObjectDeep<T, Options> : PartialObjectDeep<T, Options> : unknown