rambdax/_ts-toolbelt/src/Union/Strict.ts

Extended version of Rambda - a lightweight, faster alternative to Ramda

import {ComputeRaw} from '../Any/Compute'
import {Keys} from './Keys'
import {OptionalFlat} from '../Object/Optional'
import {Record} from '../Object/Record'

/**
 * @hidden
 */
type _Strict<U, _U = U> =
    U extends unknown
    ? U & OptionalFlat<Record<Exclude<Keys<_U>, keyof U>, never>>
    : never

/**
 * Make a [[Union]] not allow excess properties (https://github.com/Microsoft/TypeScript/issues/20863)
 * @param U to make strict
 * @returns [[Union]]
 * @example
 * ```ts
 * ```
 */
export type Strict<U extends object> =
    ComputeRaw<_Strict<U>>