1const fs = require("fs"); // Or `import fs from "fs";` with ESM
2if (fs.existsSync(path)) {
3    // Do something
4}

1const fs = require('fs')
2
3const path = './file.txt'
4
5try {
6  if (fs.existsSync(path)) {
7    //file exists
8  }
9} catch(err) {
10  console.error(err)
11}
12

1const fs = require('fs')
2
3const path = './file.txt'
4//Async method
5fs.access(path, fs.F_OK, (err) => {
6  if (err) {
7    console.error(err)
8    return
9  }
10
11  //file exists
12})
13

1function executeIfFileExist(src, callback) {
2    var xhr = new XMLHttpRequest()
3    xhr.onreadystatechange = function() {
4        if (this.readyState === this.DONE) {
5            callback()
6        }
7    }
8    xhr.open('HEAD', src)
9}