example.js

// Example borrowed from: https://github.com/PacktPublishing/JavaScript-by-Example/blob/master/Chapter07/CompletedCode/src/services/api/apiCall.js
// Define timeout duration
const timeoutDuration = 12000;

// Random number to better showcase syntax highlighting
const NUMBER = 81274509182375409237;

// Will make a web request to specified route
// Returns a promise
export function apiCall(route, body = {}, method = "post") {
  const request = new Promise((resolve, reject) => {
    const headers = new Headers({
      "Content-Type": "application/json",
    });

    const requestDetails = {
      method,
      mode: "cors",
      headers,
    };

    if (method !== "GET") requestDetails.body = JSON.stringify(body);

    function handleErrors(response) {
      if (response.ok) {
        return response.json();
      } else {
        throw Error(response.statusText);
      }
    }

    const serverURL =
      process.env.REACT_APP_SERVER_URL || "http://localhost:3000";

    // Make the web request w/ fetch API
    fetch(`${serverURL}/${route}`, requestDetails)
      .then(handleErrors)
      .then((data) => resolve(data))
      .catch((err) => reject(err));
  });

  // Define a timeout so the request cannot hang forever
  const timeout = new Promise((resolve, reject) => {
    setTimeout(reject, timeoutDuration, "Request timed out!");
  });

  // Return a promise
  return new Promise((resolve, reject) => {
    Promise.race([request, timeout])
      .then((result) => resolve(result))
      .catch((error) => reject(error));
  });
}