Native Fetch

An adapter for native fetching.

Types

interface FetchResponseLike {
  status: number
  statusText?: string
}

getFetchResponseError

Handles unsuccessful HTTP responses.

• Type:

function getFetchResponseError<
  TCustomKind extends string = never,
  TValidationErrors = ApiValidationErrors
>(
  response: FetchResponseLike,
  body?: unknown,
  options?: OkapiErrorAdapterOptions<TCustomKind, TValidationErrors>
): OkapiError<TCustomKind, TValidationErrors>

getFetchError

Handles response-like objects, network errors, and other thrown values.

• Type:

function getFetchError<
  TCustomKind extends string = never,
  TValidationErrors = ApiValidationErrors
>(
  error: unknown,
  body?: unknown,
  options?: OkapiErrorAdapterOptions<TCustomKind, TValidationErrors>
): OkapiError<TCustomKind, TValidationErrors>

createFetchResponseErrorMapper

Creates a mapper for unsuccessful HTTP responses.

• Type:

function createFetchResponseErrorMapper<
  TCustomKind extends string = never,
  TValidationErrors = ApiValidationErrors
>(options?: OkapiErrorAdapterOptions<TCustomKind, TValidationErrors>):
  FetchResponseErrorMapper<TCustomKind, TValidationErrors>

type FetchResponseErrorMapper<
  TCustomKind extends string = never,
  TValidationErrors = ApiValidationErrors,
> = (
  response: FetchResponseLike,
  body?: unknown,
) => MappedOkapiError<TCustomKind, TValidationErrors>

createFetchErrorMapper

Creates a mapper for network and other thrown errors.

• Type:

function createFetchErrorMapper<
  TCustomKind extends string = never,
  TValidationErrors = ApiValidationErrors
>(options?: OkapiErrorAdapterOptions<TCustomKind, TValidationErrors>):
  FetchErrorMapper<TCustomKind, TValidationErrors>

type FetchErrorMapper<
  TCustomKind extends string = never,
  TValidationErrors = ApiValidationErrors,
> = (error: unknown, body?: unknown) =>
  MappedOkapiError<TCustomKind, TValidationErrors>

Example

import {
  createFetchErrorMapper,
  createFetchResponseErrorMapper,
} from '@alexovn/okapi/fetch'

const mapFetchError = createFetchErrorMapper()
const mapFetchResponseError = createFetchResponseErrorMapper()

async function fetchData<T>(url: string, options?: RequestInit): Promise<T> {
  let response: Response

  try {
    response = await fetch(url, options)
  } catch (error) {
    throw mapFetchError(error)
  }

  if (!response.ok) {
    let body: unknown

    try {
      body = await response.json()
    } catch {
      // The response may have an empty or non-JSON body.
    }

    throw mapFetchResponseError(response, body)
  }

  return (await response.json()) as T
}

This example throws a mapped object to its caller. If your application expects native Error instances, use getFetchError and getFetchResponseError instead, then map the error at the UI boundary.