Result Flow

The central type in unwrapit is:

type Result<T, E = unknown> = Ok<T, E> | Err<E, T>

Every result has an ok discriminator.

import {wrap} from 'unwrapit'

const result = wrap(() => JSON.parse('{"ok":true}'))()

if (result.ok) {
  result.value
} else {
  result.error
}

Success values

Use ok(value) when you already have a successful value.

import {ok} from 'unwrapit'

const result = ok(1)

result.ok // true
result.value // 1

Error values

Use err(error) when you already have an error value.

import {err} from 'unwrapit'

const result = err(new Error('No user found'))

result.ok // false
result.error.message // No user found

Total handling with match

match is a compact way to convert both cases into one final value.

const label = result.match({
  Ok: value => `Value: ${value}`,
  Err: error => `Error: ${String(error)}`,
})

Provide both handlers when the result has not already been narrowed. A single handler is most useful after an if (result.ok) check or another narrowing step.