file watch mark

const fs = require("fs");

const performance = require('perf_hooks').performance;

var flname = "tst.txt"

var start;
var i = 0;
var aver = [];

fs.watchFile(flname, { interval: 10 }, (curr, prev) => {

    let perf = performance.now() - start;

    console.timeEnd('watch');

    console.log(perf)
    aver.push(perf);

    var sum = 0;
    for(var c = 0;c<aver.length;c++)sum+=aver[c];

    console.log('average: ' + sum/aver.length + ' by ' + aver.length)

    // console.log(`${flname} file Changed`);

    console.log('--------------------')

});

setInterval(function(){

    console.time('writeFileSync');

    fs.writeFileSync(flname, 'test - ' + ++i)

    console.timeEnd("writeFileSync");


    start = performance.now()

    console.time('watch');


}, 1500);