Function ioFetch

A wrapper around the fetch API that uses Prelude-IO's type-checking mechanisms to ensure that the response and request bodies are valid. Should mostly be compatible with the Fetch API, except Options.body's type is overwritten with the output type of the bodyBus, and the return type is an IOResult.

Example

import * as io from "@prelude-io/core";
import { ioFetch } from "@prelude-io/fetch";

const CatFact = io.Complex("CatFact", {
  fact: io.string,
  length: io.positiveNumber,
});

const CatFactsResponse = io.Complex("CatFactsResponse", {
  factCount: io.positiveNumber,
  facts: io.Vector(CatFact),
});

const CatFactRequest = io.JSON.chain(
  io.Complex("CatFactRequest", {
    facts: io.number,
  })
);

const catFactFetch = ioFetch(CatFactsResponse, CatFactRequest);

const result = await catFactFetch("https://catfacts.example.com", {
  body: { facts: 4 },
});

console.log(result); // => IORight containing `{ factCount: 4, facts: [...] }`

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