type Clean<T> = {
[key in keyof T]: T[key];
} & {}
type OptionalKeys<T> = {
[key in keyof T as undefined extends T[key] ? key : never]: T[key]
};
type OptionalUndefined<T, Props extends keyof T = keyof T> = Clean<{
[key in keyof OptionalKeys<Pick<T, Props>>]?: T[key]
} & Omit<T, keyof OptionalKeys<Pick<T, Props>>>>;
Solution by HiiiiD #33127
type OptionalUndefined<T extends object, Props extends keyof T = keyof T> =
{
[K in keyof T as undefined extends T[K] ? K extends Props ? K : never : never]?: T[K]
} & {
[K in keyof T as undefined extends T[K] ? K extends Props ? never : K : K]: T[K]
} extends infer Combined
? {[K in keyof Combined]: Combined[K]} : never
Solution by teamchong #32998
type Copy<T> = {
[P in keyof T]: T[P];
};
type OptionalUndefined<T, Props extends keyof T = keyof T, All extends keyof T = keyof T> = Copy<
{
[P in Props as undefined extends T[P] ? P : never]?: T[P];
} & {
[P in Props as undefined extends T[P] ? never : P]: T[P];
} & {
[P in Exclude<All, Props>]: T[P]
}
>;
Solution by Vampirelee #32714
type Merge<T, S> = Omit<Omit<T, keyof S> & S, never>
type OptionalUndefined<T, Props = never> = [Props] extends [never]
? Merge<T, { [K in keyof T as undefined extends T[K] ? K : never ]?: T[K] }>
: Merge<T, {
[K in keyof T as Props extends K
? undefined extends T[K] ? K : never
: never
]?: T[K]
}>
Solution by Heonys #32459
type OptionalUndefined<T, Props = unknown> = Omit<
{
[K in keyof T as undefined extends T[K]
? K extends Props
? K
: never
: never]?: T[K];
} & {
[K in keyof T as undefined extends T[K]
? K extends Props
? never
: K
: K]: T[K];
},
never
>;
Solution by vangie #32260
type OptionalUndefined<T, Props extends keyof T = keyof T> = Omit<{
[P in keyof T as P extends Props ? undefined extends T[P] ? never : P : P]: T[P]
} & {
[P in keyof T as undefined extends T[P] ? P : never]?: T[P]
}, never>
Solution by preventdefault #31725
type Intersection<A, B> = A & B extends infer I
? { [P in keyof I]: I[P] }
: never;
type OptionalFields<T, Props extends keyof T> = {
[K in Props]: undefined extends T[K] ? K : never
}[Props];
type OptionalUndefined<T, Props extends keyof T=keyof T> = Intersection<{
[K in OptionalFields<T, Props>]?: T[K];
}, {
[K in Exclude<keyof T, OptionalFields<T, Props>>]: T[K];
}>
Solution by sehyod #29970
// your answers
type OptionalUndefinedKey<T, Props extends keyof T> = {
[K in keyof T]: undefined extends T[K] ? (K extends Props ? K : never) : never
}[keyof T]
type OptionalUndefined<T,
Props extends keyof T = keyof T,
OptionalKey extends keyof T = OptionalUndefinedKey<T, Props>
> = Omit<{ [K in Exclude<keyof T, OptionalKey>]: T[K] } & { [K in OptionalKey]?: T[K] }, never>
Solution by venusliang #29829
type UndefinedFields<T extends object> = keyof {
[Key in keyof T as undefined extends T[Key] ? Key : never]?: T[Key]
}
type OptionalObject<T extends object, Props extends keyof T> = {
[Key in Extract<Props, UndefinedFields<T>>]?: T[Key]
}
type MergeSets<T extends object> = {
[Key in keyof T]: T[Key]
}
type OptionalUndefined<
T extends object,
Props extends keyof T = keyof T,
U = OptionalObject<T, Props>
> = MergeSets<Omit<T, keyof U> & U>
Solution by simone-paglino #29649
type Copy<T> = {
[K in keyof T]: T[K]
}
type OptionalUndefined<T, Props extends keyof T = keyof T> = Copy<
Omit<T, Props> &
{
[K in keyof Pick<T, Props> as undefined extends Pick<T, Props>[K] ? never : K]: Pick<T, Props>[K]
} &
{
[K in keyof Pick<T, Props> as undefined extends Pick<T, Props>[K] ? K : never]?: Pick<T, Props>[K]
}
>
Solution by XkSuperCool #28451
type GetUndefinedKey<T> =
keyof { [p in keyof T as undefined extends T[p] ? p : never]: T[p]; }
type OptionalUndefined<
T, Props extends keyof T = keyof T,
U extends keyof T = GetUndefinedKey<T> & Props
> = Omit<Omit<T, U> & Partial<Pick<T, U>>, never>
Solution by omittee #28254
type CombineObj<T extends object> = { [P in keyof T]: T[P] };
type OptionalUndefined<T, Props extends keyof T = keyof T> = CombineObj<
{ [P in keyof T & Props as Equal<Partial<T>[P], T[P]> extends true ? P : never]?: T[P] } &
{ [P in keyof T as Equal<Partial<T>[P], T[P]> extends true ? never : P]: T[P] } &
{ [P in keyof T as P extends Props ? never : P]: T[P] }>;
Solution by E-uler #28246
type OptionalUndefined<T, Props extends keyof T = keyof T> = Omit<
Omit<T, Props> & {
[K in Props as undefined extends T[K] ? K : never]?: T[K];
} & {
[K in Props as undefined extends T[K] ? never : K]: T[K];
},
never
>;
Solution by JohnLi1999 #28206
type Merge<T> = {
[K in keyof T]:T[K]
}
type OptionalUndefined<
T,
Props extends keyof T = keyof T,
OptionsProps extends keyof T =
Props extends keyof T?
undefined extends T[Props]?
Props:never
:never
> =
Merge<{
[K in OptionsProps]?:T[K]
} & {
[K in Exclude<keyof T,OptionsProps> ]:T[K]
}>
Solution by jiangshanmeta #28200
type OptionalUndefined<T, Props = keyof T, Keys extends keyof T = GetCanBeUndefinedKeys<T> & Props> = Helper<Partial<Pick<T, Keys>> & Omit<T, Keys>>
type GetCanBeUndefinedKeys<T> = keyof {
[Key in keyof T as (undefined extends T[Key] ? Key : never)]: any
}
type Helper<T> = {
[Key in keyof T]: T[Key]
}
Solution by Sun79 #28170