Run functions or await promises in a safe way by return a result object

resultOf.ts

function resultOf<T>(fn: () => T): SafeResult<T>;
function resultOf<T>(fn: () => Promise<T>): Promise<SafeResult<T>>;
function resultOf<T>(promise: Promise<T>): SafeResult<T>;
function resultOf<T>(input: (() => T | Promise<T>) | Promise<T>): Result<T> | Promise<Result<T>> {
  if (typeof input === 'function') {
    try {
      const result = input()
      if (result instanceof Promise) {
        return safe(result);
      }
      return {data: result, success: true as const};
    } catch (error) {
      return {error, success: false as const};
    }
  }
  if (input instanceof Promise) {
    return input.then(
        (data) => ({data, success: true as const}),
        (error) => ({error, success: false as const})
    );
  }
}

type Result<T> =
    { success: true, data: T, error?: never } |
    { success: false, error: unknown, data?: never };