delay.js

/** @format */

//@ts-check
/**
 
  Vodafone coding challenge
 
  You have been tasked with creating a helper function that will be used to determine the output
  of an array of data.

  Each element of the array has the following structure:

    {
      state: <String> - a state to go to
      errorCode: <String> - optional error code
    }

  The states have different functionalities:

    'processing' = delay by 2 seconds, then fetch the next state
    'error' = handle the error code provided (see below)
    'success' = return from the helper with the object: { title: 'Order complete' message: null }

  Handling error codes:

    'NO_STOCK' = return from the helper with an object: { title: 'Error page', message: 'No stock has been found' }
    'INCORRECT_DETAILS' = return from the helper with an object: { title: 'Error page', message: 'Incorrect details have been entered' }
    null = return from the helper with an object: { title: 'Error page', message: null }
    undefined = return from the helper with an object: { title: 'Error page', message: null }

  Example usage:
  -------
  getProcessingPage([{ state: 'processing' }, { state: 'error' }])
  => should return after 2 seconds with the object: { title: 'Error page', message: null }

  Notes:
  - Provide the code and a description of how to run it
**/

/**
 * Gets the processing page
 * @param {array} data
 */

const getProcessingPage = async (data = []) => {
  const error_code = {
    NO_STOCK: {
      title: 'Error page',
      message: 'No stock has been found'
    },
    INCORRECT_DETAILS: {
      title: 'Error page',
      message: 'Incorrect details have been entered'
    },
    null: {title: 'Error page', message: null},
    undefined: {title: 'Error page', message: null}
  }

  const state = {
    processing: code => {
      return new Promise(function(resolve, reject) {
        setTimeout(function() {
          resolve(state[code.state](code.errorCode || null))
        }, 2000)
      })
    },
    error: code => error_code[code],
    success: code => {
      return {title: 'Order complete', message: null}
    }
  }
  
  return await state[data[0].state](data[1])
}

/**
 *
 */

const result = getProcessingPage([{state: 'success'}, {state: 'error'}])
result.then(data => console.log('log result: ', data))