How not to exit node process when using readline-sync? - node.js

Question

I'm creating a pomodoro timer with node.
At the moment I start the project as so node start.js coding
I let that run as I do my work. When I need a break I terminate the process and the time I've spent coding get's added into a JSON file as so
{
"code": [
{
"seconds": 1,
"time": "00 : 00 : 01",
"date": "2020-06-28T03:08:42.340Z"
}
],
"read": [],
"write": []
}
Now I'm just trying to think of things I'll need in the future, I'll most definitely forget the keys in the above object. Is it code, coding, write, writing? So I thought I'd have a prompt.
var objKeys = [...Object.keys(obj), 'info']
const inputVariable = objKeys[readline.keyInSelect(objKeys, 'What are you going to be working on?')]
As it is, once I make the selection, the process terminates, I don't want that.
(I could make the selection when I want to actually terminate, but most likely that would be confusing)
Is there a way to make the selection and still keep the process running
EDIT
const time = require('./module/timeEntry');
var readline = require('readline-sync');
var obj = require('./data.json') // has the above json code
var start = process.hrtime(); // start the timer
var objKeys = Object.keys(obj)
const inputVariable = objKeys[readline.keyInSelect(objKeys, 'Which task you're going to work on?')]
function exitHandler(options, exitCode) {
if (options.cleanup) console.log('clean');
if (exitCode || exitCode === 0) {
//code
if(inputVariable !== "info"){
time.timeEntry(obj, start, inputVariable) // reads and writes to file
}
}
if (options.exit) process.exit();
}
process.on('exit', exitHandler.bind(null,{cleanup:true}));
// I want to be able to do this: `ctrl+c`
process.on('SIGINT', exitHandler.bind(null, {exit:true}));
The problem is the moment the inputVariable is entered by the user, the process ends.
time.timeEntry(obj, start, inputVariable) simply reads and writes some time keeping info into JSON.
var fs = require('fs');
var getTime = require('./getTime')
const timeEntry = (obj, start, segment ) => {
let totalSeconds = process.hrtime(start)[0];
obj[segment].push({
seconds: totalSeconds,
time: getTime.getTime(totalSeconds),
date: new Date
})
let data = JSON.stringify(obj);
fs.writeFileSync('data.json', data , 'utf-8');
}
exports.timeEntry = timeEntry;
I don't need to use readline-sync, if I instead use const inputVariable = process.argv[2] and run node start.js coding, the process wouldn't be terminated which is what I want

Answer 1

Here's what's your code is doing right now:
read in the inputVariable from the user
define a function exitHandler
tell Node to invoke exitHandler when the program exits
tell Node to invoke exitHandler upon receiving SIGINT
Note that none of these steps involves calling exitHandler, or doing anything else for that matter (e.g. there's no code here that waits for anything to happen).
Perhaps the confusion is coming from the use of process.on: this function tells Node that when it receives SIGINT (e.g. you press Ctrl-C), then it should call exitHandler. In particular, this does not tell your program "pause execution until SIGINT is received". As a result, after calling process.on, your code "continues" but there's no more code to run so the process ends (before it can ever receive SIGINT).
It seems like you want your program to do nothing until the signal is received; in that case you could add
while (true) {}
or similar at the end. So your code will do nothing (forever), until it receives SIGINT, then it will call exitHandler.