What is the correct Twilio Function callback? - twilio

Question

I am new to Twilio and want to include a kind of switch in my Studio Flow Chart that checks if we are in the defined business hours. If yes (success), it forwards to the number, if no (fail), it forwards to voicemail.
I tried to build a function, somewhat derived from this twilio git: https://github.com/twilio-labs/function-templates/tree/main/voicemail.
const moment = require('moment');
const DEFAULT_UTC_OFFSET = 0;
const DEFAULT_WORK_WEEK_START = 1; // Monday
const DEFAULT_WORK_WEEK_END = 5; // Friday
const DEFAULT_WORK_HOUR_START = 8; // 8:00, 8AM
const DEFAULT_WORK_HOUR_END = 18; // 18:59, 6:59PM
function getInteger(stringValue, defaultValue) {
const parsedNumber = parseInt(stringValue, 10);
if (isNaN(parsedNumber)) {
return defaultValue;
}
return parsedNumber;
}
exports.handler = function(context, event, callback) {
const timezone = getInteger(context.TIMEZONE_OFFSET, DEFAULT_UTC_OFFSET);
const workWeek = {
start: getInteger(context.WORK_WEEK_START, DEFAULT_WORK_WEEK_START),
end: getInteger(context.WORK_WEEK_END, DEFAULT_WORK_WEEK_END),
};
const workHour = {
start: getInteger(context.WORK_HOUR_START, DEFAULT_WORK_HOUR_START),
end: getInteger(context.WORK_HOUR_END, DEFAULT_WORK_HOUR_END),
};
const currentTime = moment().utcOffset(timezone);
const hour = currentTime.hour();
const day = currentTime.day();
// between monday and friday
const isWorkingDay = day <= workWeek.end && day >= workWeek.start;
// between 8am and 7pm
const isWorkingHour = hour <= workHour.end && hour >= workHour.start;
if (isWorkingDay && isWorkingHour) {
return true;
} else {
return false;
}
};
From the error I get (82002 – runtime application timed out), the callback must be different. What is the correct way for callback(err, response)?
Thanks.

Answer 1

Twilio developer evangelist here.
In a Twilio Function, in order to return a result you must call the callback function that is passed in as the third parameter to your handler function. You are getting a timeout here because you never call the callback so the function runs for 10 seconds then times out.
I'd try returning the data like this:
if (isWorkingDay && isWorkingHour) {
return callback(null, true);
} else {
return callback(null, false);
}
};
Note that it might not like primitive boolean values, so if that doesn't work, try a JavaScript object like:
if (isWorkingDay && isWorkingHour) {
return callback(null, { inWorkingTime: true });
} else {
return callback(null, { inWorkingTime: false });
}
};