@swan-io/request

@swan-io/request

Wrapper for XMLHttpRequest with better data-structures

Installation

$ yarn add @swan-io/request @swan-io/boxed
# --- or ---
$ npm install --save @swan-io/request @swan-io/boxed

Design principles

• Has a strong contract with data-structures from Boxed (Future, Result & Option)
• Makes the request easily cancellable with Future API
• Gives freedom of interpretation for response status
• Handles timeouts
• Types the response using the provided type

Getting started

import { Request, badStatusToError, emptyToError } from "@swan-io/request";

// Regular case
Request.make({ url: "/api/health" }).onResolve(console.log);
// Result.Ok({status: 200, ok: true, response: Option.Some("{\"ok\":true}")})

// Timeout
Request.make({ url: "/api/health", timeout: 2000 }).onResolve(console.log);
// Result.Error(TimeoutError)

// Network error
Request.make({ url: "/api/health" }).onResolve(console.log);
// Result.Error(NetworkError)

// Custom response type
Request.make({ url: "/api/health", responseType: "json" }).onResolve(
  console.log,
);
// Result.Ok({status: 200, ok: true, response: Option.Some({ok: true})})

// Handle empty response as an error
Request.make({ url: "/api/health" })
  .mapOkToResult(emptyToError)
  .onResolve(console.log);
// Result.Error(EmptyResponseError)

// Handle bad status as an error
Request.make({ url: "/api/health" })
  .mapOkToResult(badStatusToError)
  .onResolve(console.log);
// Result.Error(BadStatusError)

// Cancel request
useEffect(() => {
  const future = Request.make({ url: "/api/health" });
  return () => future.cancel();
}, []);

API

Request.make(config)

config

• url: string
• method: GET (default), POST, OPTIONS, PATCH, PUT or DELETE
• type:
  • text: (default) response will be a string
  • arraybuffer: response will be a ArrayBuffer
  • blob: response will be Blob
  • json: response will be a JSON value
• body: request body
• headers: a record containing the headers
• creatials: omit, same-origin or include
• onLoadStart: event triggered on load start
• timeout: number

Return value

Returns a Future<Result<Response<T>, NetworkError | TimeoutError>>, where Response<T> has the following properties:

• status: number
• ok: boolean
• response: Option<T>
• xhr: XMLHttpRequest

T is the type associated with the responseType provided in the config object.

emptyToError

Helper to use with mapOkToResult to consider empty response as an error.

badStatusToError

Helper to use with mapOkToResult to consider a status outside of the 200-299 range as an error.

License