如何将消息保存到txt？

Question

When I try to save chat between me and customer to txt file I cannot figure it out because when I try to code it in it will save only 1 message at time and when someone else sends message it will rewrite the txt file example: I sent: What do you need help with?

In TXT: 
User: *me*
Message: *What do you need help with?*
Channel: *channel name*

But when he answers it it will rewrite the txt to his message

How I want it to be:

In TXT: 
User: *me*
Message: *What do you need help with?*
Channel: *channel name*
=======================================
User: *Customer*
Message: *Customer's reply*
Channel: *channel name*
=======================================

But I'll get:

In TXT:
User: *Customer*
Message: *Customer's reply*
Channel: *channel name*

I want to save all things we send but in txt it will save just the newest.

How do I solve the problem?

Answer 1

I don't know how you did it before, but I would do it like this:

const fs = require("fs");

# FIRST MESSAGE
fs.writeFileSync("/1.txt", `User: ${username}\nMessage: ${messageContent}\nChannel: ${channelName}`)

# SECOND MESSAGE
let fileContent = fs.readFileSync("/1.txt").toString();
fs.writeFileSync("/1.txt", fileContent + `\n-\nUser: ${username}\nMessage: ${messageContent}\nChannel: ${channelName}`);

# and so on