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Good error handling in Typescript
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| export type Success<T> = { | |
| data: T | |
| error: undefined | |
| } | |
| export type Failure<E> = { | |
| data: undefined | |
| error: E | |
| } | |
| export type Result<T, E = Error> = Success<T> | Failure<E> | |
| export async function tryCatch<T, E extends Error = Error>( | |
| promise: Promise<T> | |
| ): Promise<Result<T, E>> { | |
| try { | |
| const data = await promise | |
| return { data, error: undefined } | |
| } catch (error) { | |
| const finalError = error as E | |
| return { data: undefined, error: finalError } | |
| } | |
| } | |
| export function trySync<T, E extends Error = Error>(fn: () => T): Result<T, E> { | |
| try { | |
| const data = fn() | |
| return { data, error: undefined } | |
| } catch (error) { | |
| const finalError = error as E | |
| return { data: undefined, error: finalError } | |
| } | |
| } | |
| export class WrappedError<E extends Error = Error> extends Error { | |
| cause: E | |
| constructor(message: string, cause: E) { | |
| super(message) | |
| this.name = "WrappedError" | |
| this.cause = cause | |
| if (Error.captureStackTrace) { | |
| Error.captureStackTrace(this, WrappedError) | |
| } | |
| } | |
| unwrap(): E { | |
| return this.cause | |
| } | |
| toString(): string { | |
| if (this.cause) { | |
| return `${this.message}: ${this.cause.message}` | |
| } | |
| return this.message | |
| } | |
| static cause<T extends Error>(error: WrappedError<T>): T { | |
| let result: Error = error.unwrap() | |
| while (result instanceof WrappedError) { | |
| result = result.unwrap() | |
| } | |
| return result as T | |
| } | |
| } | |
| export function wrap<E extends Error>( | |
| cause: E, | |
| message: string | |
| ): WrappedError<E> { | |
| return new WrappedError(message, cause) | |
| } | |
| export const Errors = Object.freeze({ | |
| try: tryCatch, | |
| trySync, | |
| wrap, | |
| WrappedError | |
| }) |
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