import {Primitive} from './basic';
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/**
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Create a type from another type with all keys and nested keys set to optional.
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Use-cases:
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- Merging a default settings/config object with another object, the second object would be a deep partial of the default object.
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- Mocking and testing complex entities, where populating an entire object with its keys would be redundant in terms of the mock or test.
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@example
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```
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import {PartialDeep} from 'type-fest';
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const settings: Settings = {
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textEditor: {
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fontSize: 14;
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fontColor: '#000000';
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fontWeight: 400;
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}
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autocomplete: false;
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autosave: true;
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};
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const applySavedSettings = (savedSettings: PartialDeep<Settings>) => {
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return {...settings, ...savedSettings};
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}
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settings = applySavedSettings({textEditor: {fontWeight: 500}});
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```
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*/
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export type PartialDeep<T> = T extends Primitive
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? Partial<T>
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: T extends Map<infer KeyType, infer ValueType>
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? PartialMapDeep<KeyType, ValueType>
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: T extends Set<infer ItemType>
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? PartialSetDeep<ItemType>
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: T extends ReadonlyMap<infer KeyType, infer ValueType>
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? PartialReadonlyMapDeep<KeyType, ValueType>
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: T extends ReadonlySet<infer ItemType>
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? PartialReadonlySetDeep<ItemType>
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: T extends ((...arguments: any[]) => unknown)
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? T | undefined
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: T extends object
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? PartialObjectDeep<T>
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: unknown;
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/**
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Same as `PartialDeep`, but accepts only `Map`s and as inputs. Internal helper for `PartialDeep`.
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*/
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interface PartialMapDeep<KeyType, ValueType> extends Map<PartialDeep<KeyType>, PartialDeep<ValueType>> {}
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/**
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Same as `PartialDeep`, but accepts only `Set`s as inputs. Internal helper for `PartialDeep`.
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*/
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interface PartialSetDeep<T> extends Set<PartialDeep<T>> {}
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/**
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Same as `PartialDeep`, but accepts only `ReadonlyMap`s as inputs. Internal helper for `PartialDeep`.
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*/
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interface PartialReadonlyMapDeep<KeyType, ValueType> extends ReadonlyMap<PartialDeep<KeyType>, PartialDeep<ValueType>> {}
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/**
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Same as `PartialDeep`, but accepts only `ReadonlySet`s as inputs. Internal helper for `PartialDeep`.
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*/
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interface PartialReadonlySetDeep<T> extends ReadonlySet<PartialDeep<T>> {}
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/**
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Same as `PartialDeep`, but accepts only `object`s as inputs. Internal helper for `PartialDeep`.
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*/
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type PartialObjectDeep<ObjectType extends object> = {
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[KeyType in keyof ObjectType]?: PartialDeep<ObjectType[KeyType]>
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};
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