Usage

const result = await defer(async (defer) => {
  const fileHandle = await openFile("path/to/file");
  defer(() => fileHandle.close());

  // Perform operations on the file
  return processFile(fileHandle);
});

Installation

CLI

npx atmx add helper defer

Manually

Copy and paste the following method into @/utils/helpers/defer.ts:

import { tryit } from "@/helpers/tryit.ts";

/**
* Useful when for script like things where cleanup should be done on
* fail or sucess no matter.
*
* You can call defer many times to register many deferred functions
* that will all be called when the function exits in any state.
*
* @example
* const result = await defer(async (defer) => {
*   const fileHandle = await openFile('path/to/file')
*   defer(() => fileHandle.close())
*
*   // Perform operations on the file
*   return processFile(fileHandle)
* })
*/
export async function defer<TResponse>(
func: (
register: (
  fn: (error?: any) => any,
  options?: { rethrow?: boolean },
) => void,
) => Promise<TResponse>,
): Promise<TResponse> {
const callbacks: {
fn: (error?: any) => any;
rethrow: boolean;
}[] = [];
const register = (
fn: (error?: any) => any,
options?: { rethrow?: boolean },
) =>
callbacks.push({
  fn,
  rethrow: options?.rethrow ?? false,
});
const [err, response] = await tryit(func)(register);
for (const { fn, rethrow } of callbacks) {
const [rethrown] = await tryit(fn)(err);
if (rethrown && rethrow) {
  throw rethrown;
}
}
if (err) {
throw err;
}
return response;
}