👐 cope

Simple helper to handle errors, inspired by Golang solution

💿 Installation

pnpm i cope

Other package managers

npm i cope

yarn add cope

❓ Why

• Simplicity: Avoid try/catch blocks scattered across your code
• Type Safety: You know exactly what types to expect in success and failure cases
• Consistency: Standardized structure for handling errors in sync and async code

💡 Examples

Basic usage:

import { cope } from 'cope';

const [result, error] = cope(() => JSON.parse('{"a": 123}'));

if (error)
  // process error
else
  // process result

Usage with default:

const [result = {count: 0}, error] = cope(() => JSON.parse('_broken_"count": 123}'));
if (error)
  console.warn('fail')

// result is always defined

Note

This is why, the util returns undefined instead of null

Usage with optional execution:

cope(() => window.querySelector('#dynamic-element').scrollTo(123, 0))
// ...guaranteed executions

Asynchronous usage:

Stepwise

const [fetchResult, fetchingError] = await cope(() => fetch('https://example.com'));
if (fetchingError) {
  console.error('Request failed')
  return
}

const [result = null, parsingError] = await cope(() => fetchResult.json());
if (parsingError)
  console.warn('Cannot parse response data')

// process result

Or just

const [result = null, error] = await cope(
  () => fetch('https://example.com')).then(d=>d.json())
);
if (error) {
  console.error('Somewhere failed 🌚')
  return
}

// process result

🛠️ API

cope<Throws, Executor, Result>(executor: Executor): CopeResult<Result, Throws>

• Generics

  • Throws - You can define types of errors, that can be thrown by executor. Default is Error
  • Executor - Private, don't change it!
  • Result - Private, don't change it!

• Parameters

  • executor (Function): The function to be executed. It can be either a synchronous or asynchronous function.

• Returns

  • If sync executor - [Result, undefined] | [undefined, Throws]
  • If async executor - Promise<[Result, undefined] | [undefined, Throws]>