Mock HTTP request in javascript using promise and timeout.

mock-http.js

const mock = (success, timeout = 1000) => {
  return new Promise((resolve, reject) => {
    setTimeout(() => {
      if(success) {
        resolve();
      } else {
        reject({message: 'Error'});
      }
    }, timeout);
  });
}

const someEvent = async () => {
  try {
    await mock(true, 1000);
  } catch (e) {
    console.log(e.message);
  }
}

another version

const getMockData = async (options = {
  data: '',
  error: 'unknown server error',
  delay: null
}) => {
  const {data, error, delay} = options;
  return new Promise((resolve, reject) => {
    setTimeout(() => {
      if(!!data) {
        resolve({
          type: 'Success ✅',
          data,
        });
      } else {
        reject({
          type: 'Error ❌',
          message: error,
        });
      }
    }, delay || 1000);
  });
}

// test cases
(async () => {
  try {
    const success = await getMockData({data: [1,2,3]});
    console.log(success.data);
  } catch (err) {
    console.log(err.message);
  }
  try {
    const error = await getMockData({error: '404 not found error', delay: 3000});
    console.log(error);
  } catch (err) {
    console.log(err.message);
  }
})();