| 1234567891011121314151617181920212223242526272829303132 |
- /**
- Create a type that makes the given keys optional. The remaining keys are kept as is. The sister of the `SetRequired` type.
- Use-case: You want to define a single model where the only thing that changes is whether or not some of the keys are optional.
- @example
- ```
- import {SetOptional} from 'type-fest';
- type Foo = {
- a: number;
- b?: string;
- c: boolean;
- }
- type SomeOptional = SetOptional<Foo, 'b' | 'c'>;
- // type SomeOptional = {
- // a: number;
- // b?: string; // Was already optional and still is.
- // c?: boolean; // Is now optional.
- // }
- ```
- */
- export type SetOptional<BaseType, Keys extends keyof BaseType = keyof BaseType> =
- // Pick just the keys that are not optional from the base type.
- Pick<BaseType, Exclude<keyof BaseType, Keys>> &
- // Pick the keys that should be optional from the base type and make them optional.
- Partial<Pick<BaseType, Keys>> extends
- // If `InferredType` extends the previous, then for each key, use the inferred type key.
- infer InferredType
- ? {[KeyType in keyof InferredType]: InferredType[KeyType]}
- : never;
|
