Proposal
Adding a utility type for discriminated unions to select specific types using discriminator value.
Example:
export type DiscriminateUnion<T, K extends keyof T, V extends T[K]> =
T extends Record<K, V> ? T : never
export type T1 = { type: 'title', data: string } | { type: 'email', data: string } | { type: 'number', data: number } | { type: 'file': data: { url: string }}
// T2 is "{ type: 'title', data: string }"
export type T2 = DiscriminateUnion<T1, 'type', 'title'>
// T3 is "{ type: 'file': data: { url: string }"
export type T3 = DiscriminateUnion<T1, 'type', 'file'>
// T4 is "{ type: 'title', data: string } | { type: 'email', data: string }"
export type T4 = DiscriminateUnion<T1, 'type', 'title' | 'number''>
sindresorhus / type-fest
A collection of essential TypeScript types
14.5k
How does funding with Polar work?
1
Pay now to fund the work behind this issue.
2
Get updates on progress being made.
3
Maintainer is rewarded once the issue is completed.
FAQ
Backer
You're funding impactful open source efforts
Contributor
You want to contribute to this effort
Maintainer
You want to get funding like this too