OptionalKeysOf<BaseType>

OptionalKeysOf<BaseType> = BaseType extends unknown ? keyof { [Key in keyof BaseType as BaseType extends Record<Key, BaseType[Key]> ? never : Key]: never } & keyof BaseType : never

Defined in: packages/react-querybuilder/src/types/type-fest/optional-keys-of.ts:34

Extract all optional keys from the given type.

This is useful when you want to create a new type that contains different type values for the optional keys only.

Type Parameters

Type Parameter
BaseType extends object

Example

import type {OptionalKeysOf, Except} from 'type-fest';

interface User {
	name: string;
	surname: string;

	luckyNumber?: number;
}

const REMOVE_FIELD = Symbol('remove field symbol');
type UpdateOperation<Entity extends object> = Except<Partial<Entity>, OptionalKeysOf<Entity>> & {
	[Key in OptionalKeysOf<Entity>]?: Entity[Key] | typeof REMOVE_FIELD;
};

const update1: UpdateOperation<User> = {
	name: 'Alice'
};

const update2: UpdateOperation<User> = {
	name: 'Bob',
	luckyNumber: REMOVE_FIELD
};

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caution

API documentation is generated from the latest commit on the main branch. It may be somewhat inconsistent with official releases of React Query Builder.