Correct solution for LFW211 Labs 9.2?

faddah

Hello,

I'm going through the Linux Foundation / OpenJS course for certification, Node.JS Applications. I'm on Chapter 9, and doing the Labs Exercise 9.2 (labs-2). Here is the code with which I'm presented —

'use strict'

const { EventEmitter } = require('events')

process.nextTick(console.log, 'passed!')

const ee = new EventEmitter()

ee.emit('error',Error('timeout'))

The exercise then says to...:

Currently the process crashes... Without removing any of the existing code, and without using a try/catch block add some code which stops the process from crashing. When implemented correctly the process should out put passed!.

So here's my solution —

'use strict'
const { EventEmitter } = require('events')

const ee = new EventEmitter()

ee.on('error', () => process.nextTick(console.log, 'passed!'))

ee.emit('error', Error('timeout'))

This works, when I run node index.js, I do get the desired result —

Here's my question — is this a correct solution? I don't use a setTimeout(), either the regular one from JavaScript or the "Promisfied" one from Node.JS, I used an ee.on('error', ...). The exercise also says to do this,...

Without removing any of the existing code, and without using a try/catch block...

I didn't re-write any code, but I did wrap the process.nextTick() line in the ee.on('error', ...) and moved it down below the ee declaration so it would work. Is that correct? Please let me know.

best,

faddah

abraham.m.joseph

This works. You can also just add
ee.on('error', () => {});
just before ee.emit in the original code. (just an empty handler is enough)

xdxmxc

@faddah that would be rewriting the code - as @abraham.m.joseph says, attach an error handler

ailequal

I was also having some doubts when doing this exercise, mainly because the solution that @abraham.m.joseph suggested needs to add the code before the ee.emit() part, which someone might consider as modifying the original code, but I am glad to see that it's the correct way in the end.

xdxmxc

Without removing any of the existing code, and without using a try/catch block add some code which stops the process from crashing

is not the same as modifying, on being before emit is the point of the exercise