How to use fs.watchFile to reload Json File - node.js

Question

I have couple functions that re-structure the JSON file. They write and manipulate one another. They are in the same js file. Every function depends on the function before to run properly. But since every one of them manipulates the file synchronously after reading it, I have encountered a problem which is hard to explain for me because I am not sure if I understand it well. When the first function finishes the task second function can't read it(It reads but can't see the updated object and its property). If I run all the functions one by one and restart the program afterward, it reads very well. Here is what I have tried until now;
I tried to make my functions asynchronous
I tried to use setTimeout function and give it up until 10 seconds
Both did not work for me. I read in StackOverflow that it fs.watch could help me but couldn't find a proper explanation of how to implement that. Any help regarding this issue I am having would be much appreciated.
-I know I can use another database but I just want to know this one because I am regularly using this. Please don't be rude if I am stupid :P
const fs = require('fs');
const ReadRawData= fs.readFileSync('Data.json');
const ReadParsed = JSON.parse(ReadRawData);
fs.watchFile('Data.json', (curr, prev) => {
console.log(`the current mtime is: ${curr.mtime}`);
console.log(`the previous mtime was: ${prev.mtime}`);
});
I just want to know how can I reload this ReadParsed everytime a file changed and can reach the reloaded version from functions.
Here is my full code; This is testing2.js
const request = require('request');
const cherio= require('cheerio');
const fs = require('fs');
const cheerioTableparser = require('cheerio-tableparser');
async function htmlCollector () {
const ReadTransactionBase = await fs.readFileSync('transactionDatabase.json');
const ReadTransaction = JSON.parse(ReadTransactionBase);
ReadTransaction.pageInformation = "";
let editedDataBase = JSON.stringify(ReadTransaction, null, 2);
fs.writeFileSync('transactionDatabase.json', editedDataBase);
for (let counter = 1; counter <= ReadTransaction.maxPage; counter++) {
request(ReadTransaction.link + counter,
(error, response, html) => {
if (!error && response.statusCode === 200) {
const $ = cherio.load(html);
const items = [];
$('#maindiv').each(function (i, elem) {
items[i] = $(this).html();
});
let newPage = {['PageNumber'+counter] : items};
ReadTransaction.pageInformation = Object.assign(newPage,ReadTransaction.pageInformation);
let editedDataBase = JSON.stringify(ReadTransaction, null, 2);
fs.writeFileSync('transactionDatabase.json', editedDataBase);
}
})
}
}
async function databaseModifier () {
const ReadTransactionBase = await fs.readFileSync('transactionDatabase.json');
const ReadTransaction = JSON.parse(ReadTransactionBase);
delete ReadTransaction.from;
delete ReadTransaction.quantities;
delete ReadTransaction.orangeBox;
let editedDataBase = JSON.stringify(ReadTransaction, null, 2);
console.log('test');
fs.writeFileSync('transactionDatabase.json', editedDataBase);
for (let i=1; i<=Object.keys(ReadTransaction.pageInformation).length;i++) {
let nums = 'PageNumber' + i;
let newObject = {[nums]: {}};
ReadTransaction.from = Object.assign(newObject,ReadTransaction.from);
ReadTransaction.orangeBox = Object.assign(newObject,ReadTransaction.orangeBox);
ReadTransaction.quantities = Object.assign(newObject,ReadTransaction.quantities);
let editedDataBase = JSON.stringify(ReadTransaction, null, 2);
fs.writeFileSync('transactionDatabase.json', editedDataBase);
}
}
async function fromOrangeBoxQuantities () {
const ReadTransactionBase = await fs.readFileSync('transactionDatabase.json');
const ReadTransaction = JSON.parse(ReadTransactionBase);
for (let counter = 1; counter <= ReadTransaction.maxPage ; counter++) {
let HTMLPageNumber = 'PageNumber' + counter;
let $ = cherio.load(ReadTransaction.pageInformation[HTMLPageNumber][0]);
cheerioTableparser($);
let data = $('.table').parsetable(true,true,true);
for (let sCounter = 1; sCounter <= data[2].length; sCounter++) {
let fromTable = {[sCounter] : [data[2][sCounter-1]]};
let orangeBoxTable = {[sCounter] : [data[3][sCounter-1]]};
let quantityTable = {[sCounter] : [data[5][sCounter-1]]};
ReadTransaction.from[HTMLPageNumber] = Object.assign(fromTable,ReadTransaction.from[HTMLPageNumber]);
ReadTransaction.orangeBox[HTMLPageNumber] = Object.assign(orangeBoxTable,ReadTransaction.orangeBox[HTMLPageNumber]);
ReadTransaction.quantities[HTMLPageNumber] = Object.assign(quantityTable,ReadTransaction.quantities[HTMLPageNumber]);
let editedDataBase = JSON.stringify(ReadTransaction, null, 2);
fs.writeFileSync('transactionDatabase.json', editedDataBase);
}
}
}
async function validatorOfTransactions (){
const ReadTransactionBase = await fs.readFileSync('transactionDatabase.json');
const ReadTransaction = JSON.parse(ReadTransactionBase);
ReadTransaction.validQuantities = [];
let editedDataBase = JSON.stringify(ReadTransaction, null, 2);
fs.writeFileSync('transactionDatabase.json', editedDataBase);
for (let counter = 1; counter <= ReadTransaction.maxPage ; counter++) {
let HTMLPageNumber = 'PageNumber' + counter;
let length = Object.keys(ReadTransaction.from[HTMLPageNumber]).length;
for (let sCounter = 1; sCounter <= length; sCounter++) {
let a = ReadTransaction.from[HTMLPageNumber][sCounter].toString();
let b = ReadTransaction.fromAddress;
let c = ReadTransaction.orangeBox[HTMLPageNumber][sCounter].toString();
let d = ReadTransaction.OrangeBox;
if (a === b && c === d) {
console.log('yay');
ReadTransaction.validQuantities.push(parseFloat(ReadTransaction.quantities[HTMLPageNumber][sCounter].toString().replace(/,/g,'')));
let editedDataBase = JSON.stringify(ReadTransaction, null, 2);
fs.writeFileSync('transactionDatabase.json', editedDataBase);
}
}
}
}
async function finalizeCalculation () {
const ReadTransactionBase = await fs.readFileSync('transactionDatabase.json');
const ReadTransaction = JSON.parse(ReadTransactionBase);
let NewArray = ReadTransaction.validQuantities;
return NewArray.reduce((a,b) => a +b, 0);
}
module.exports = {
htmlCollector : htmlCollector,
databaseModifier : databaseModifier,
fromOrangeBoxQuantities : fromOrangeBoxQuantities,
validatorOfTransactions : validatorOfTransactions,
finalizeCalculation : finalizeCalculation
};
This is transactionDatabase.json;
{
"link": "https://etherscan.io/token/generic-tokentxns2?contractAddress=0xaf2de5cb07d8f5de2369ff104150fef9dc0e604b&mode=&a=0x11209cbc2ea8cf829aa5aa1cdc5a4e5962e70655&p=",
"maxPage": 12,
"fromAddress": "0x11209cbc2ea8cf829aa5aa1cdc5a4e5962e70655",
"OrangeBox": "OUT",
"validQuantities": [],
"pageInformation": {}
}
this is newtest.js;
let testing2 = require('./testing2');
testing2.htmlCollector().then(() => testing2.databaseModifier().then(()=> testing2.fromOrangeBoxQuantities().then(()=> testing2.validatorOfTransactions().then())));
Here is the error I am getting;
(node:21760) UnhandledPromiseRejectionWarning: TypeError: Cannot read property '0' of undefined