Skip to main content

Function: orAsync()

Returns a promise that resolves to the only value in asyncIterable if it contains exactly one value. Otherwise, returns a promise that resolves to the awaited result of invoking fn.

Example​

import { asAsync, findAsync, orAsync, pipe } from 'lfi'

const API_URL = `https://api.dictionaryapi.dev/api/v2/entries/en`

const findWordWithPartOfSpeech = partOfSpeech =>
  pipe(
    asAsync([`sloth`, `lazy`, `sleep`]),
    findAsync(async word => {
      const response = await fetch(`${API_URL}/${word}`)
      const [{ meanings }] = await response.json()
      return meanings.some(meaning => meaning.partOfSpeech === partOfSpeech)
    }),
    orAsync(() => `no ${partOfSpeech}???`),
  )

console.log(await findWordWithPartOfSpeech(`noun`))
//=> sloth
console.log(await findWordWithPartOfSpeech(`verb`))
//=> sloth
console.log(await findWordWithPartOfSpeech(`adjective`))
//=> lazy
console.log(await findWordWithPartOfSpeech(`adverb`))
//=> no adverb???
Playground

Since​

v0.0.1

Call Signature​

orAsync<Value>(fn): (asyncIterable) => Promise<Value>

Type Parameters​

• Value

Parameters​

fn​

() => MaybePromiseLike<Value>

Returns​

Function

Parameters​

asyncIterable​

AsyncIterable<Value, any, any>

Returns​

Promise<Value>

Defined in​

optionals.d.ts:105

Call Signature​

orAsync<Value>(fn, asyncIterable): Promise<Value>

Type Parameters​

• Value

Parameters​

fn​

() => MaybePromiseLike<Value>

asyncIterable​

AsyncIterable<Value, any, any>

Returns​

Promise<Value>

Defined in​

optionals.d.ts:108