fs.existsSync is not waiting for fs.readFile inside if - node.js

Question

if (fs.existsSync('tmp/cache.txt')) {
fs.readFile("tmp/cache.txt", function (err, data) {
if (data != "" || data != "[]") {
jdata = JSON.parse(data);
if (
jdata[jdata.length - 1].substring(4, 8) ==
new Date().getFullYear() + 543
) {
year = new Date().getFullYear() + 542;
console.log("yes this year");
}
jdata.forEach(function (value, i) {
if (
value.substring(4, 8) ==
new Date().getFullYear() + 543
) {
countloveme--;
}
});
jdata.splice(countloveme);
}
});
}
my code is running but
code is finished before fs.readFile inside ifelse have finish
i don't how to add await in fs.readFile or anyway to this code is working

Answer 1

As written in the comments, it would be a better choice to use fs,readFileSync
And when you use Array.forEach() you are starting a new function that is running synchronously.
I've cleared your code maybe this can help you
if (fs.existsSync('tmp/cache.txt')) {
try {
const data = fs.readFileSync("tmp/cache.txt");
if (!data || data != "" || data != "[]")
throw new Error('tmp/cache.txt file is empty');
const jdata = JSON.parse(data);
// More clear to use variables in the if elses
const arg1 = jdata[jdata.length - 1].substring(4, 8)
const arg2 = new Date().getFullYear() + 543;
if (arg1 === arg2) {
// You don't use this date anywhere?
new Date().getFullYear() + 542;
console.log("yes this year");
}
for (let dataChunk of jdata) {
if (
dataChunk.substring(4, 8) ==
new Date().getFullYear() + 543
) {
countloveme--;
}
}
jdata.splice(countloveme);
} catch (error) {
console.error(error.message);
}
}