Getting Started

Install unwrapit from npm:

npm i unwrapit

Wrap a function

wrap converts a throwing function into a function that returns Result.

import {wrap} from 'unwrapit'

const parseJson = wrap(JSON.parse)
const result = parseJson('{"name":"unwrapit"}')

if (!result.ok) {
  console.error(result.error)
} else {
  console.log(result.value.name)
}

Wrap an async function

Async functions return Promise<Result<T, E>>.

import {wrap} from 'unwrapit'

const get = wrap(fetch)
const result = await get('https://example.com')

if (result.ok) {
  console.log(result.value.status)
} else {
  console.error(result.error)
}

Wrap a promise

You can also pass a promise value directly.

import {wrap} from 'unwrapit'

const result = await wrap(Promise.resolve('ready'))

console.log(result.unwrap()) // ready

Wrap a plain value

Plain values become successful results.

import {wrap} from 'unwrapit'

const result = wrap({name: 'unwrapit'})

console.log(result.unwrap().name)

Prefer explicit handling

unwrap() is useful when failure should panic, but most app code should inspect result.ok or use match.

const message = result.match({
  Ok: value => `Loaded ${value.name}`,
  Err: error => `Failed: ${String(error)}`,
})