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TypeScript type to await an array of Results
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| type ResultSuccess<T> = { success: true; value: T }; | |
| type ResultFailure<T> = { success: false; error: T }; | |
| type ExtractFailure<T> = T extends ResultFailure<infer U> ? U : never; | |
| type ExtractSuccess<T> = T extends ResultSuccess<infer U> ? U : never; | |
| /** | |
| * Represents the awaited results of an array of promises, each of which can resolve | |
| * to either `ResultSuccess` or `ResultFailure`. | |
| * | |
| * This type resolves to a `Promise` that either: | |
| * - Contains a `ResultSuccess<T>` object with a tuple reflecting the successful results | |
| * of each promise in `T`. If a promise in the array does not resolve to `ResultSuccess`, | |
| * its corresponding type in the tuple will be `never`. | |
| * - Or, if any of the promises in the array results in a `ResultFailure`, a union type | |
| * of the error types from the failures is added. | |
| * | |
| * @template T An array of promises, each resolving to either `ResultSuccess` or `ResultFailure`. | |
| * @see https://gist.github.com/albertms10/530670e632983bd9dc4e046f5f5628e3 | |
| * | |
| * @example | |
| * // If all promises result in success: | |
| * type Example1 = AwaitedResults<[Promise<ResultSuccess<string>>, Promise<ResultSuccess<number>>]>; | |
| * // Promise<ResultSuccess<[string, number]>> | |
| * | |
| * @example | |
| * // If any promise results in failure: | |
| * type Example2 = AwaitedResults<[Promise<ResultSuccess<string> | ResultFailure<number>>, Promise<ResultFailure<boolean>>]>; | |
| * // Promise<ResultSuccess<[string, never]> | ResultFailure<number | boolean>> | |
| */ | |
| export type AwaitedResults<T extends readonly any[]> = Promise< | |
| | ResultSuccess<{ | |
| [K in keyof T]: ExtractSuccess<Awaited<T[K]>> extends never | |
| ? never | |
| : ExtractSuccess<Awaited<T[K]>>; | |
| }> | |
| | (ExtractFailure<Awaited<T[number]>> extends never | |
| ? never | |
| : ResultFailure<ExtractFailure<Awaited<T[number]>>>) | |
| >; |
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