Function fallback

Example

import { fallback } from "@daiso-tech/core/async";
import { AsyncHooks } from "@daiso-tech/core/utilities";

const fetchData = new AsyncHooks(async (url: string): Promise<unknown> => {
  const response = await fetch(url);
  const json = await response.json();
  if (!response.ok) {
    throw json
  }
  return json;
}, [
  fallback({ fallbackValue: null })
]);

// Will return null when the fetch method throws an error.
console.log(await fetchData.invoke("URL_ENDPOINT"));
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The middleware works also when the function returns a Result type.

Example

import { fallback } from "@daiso-tech/core/async";
import { AsyncHooks, Result, resultFailure, resultSuccess } from "@daiso-tech/core/utilities";

const fetchData = new AsyncHooks(async (url: string): Promise<Result> => {
  const response = await fetch(url);
  const json = await response.json();
  if (!response.ok) {
    return resultFailure(json);
  }
  return resultSuccess(json);
}, [
  fallback({ fallbackValue: null })
]);

// Will return null when the fetch method throws an error.
console.log(await fetchData.invoke("URL_ENDPOINT"));
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