@lodestar/beacon-node/src/util/wrapError.ts

A Typescript implementation of the beacon chain

export type Result<T> = {err: null; result: T} | {err: Error};

/**
 * Wraps a promise to return either an error or result
 * Useful for SyncChain code that must ensure in a sample code
 * ```ts
 * try {
 *   A()
 * } catch (e) {
 *   B()
 * }
 * ```
 * only EITHER fn A() and fn B() are called, but never both. In the snipped above
 * if A() throws, B() would be called.
 */
export async function wrapError<T>(promise: Promise<T>): Promise<Result<T>> {
  try {
    return {err: null, result: await promise};
  } catch (err) {
    return {err: err as Error};
  }
}

/**
 * Some functions may want to return a result and some warning typed as Error
 */
export type WarnResult<T, E extends Error> = {result: T; warnings: E[] | null};