Writing to file in NodeJS calling from another JS file

Question

I am having a weird issue writing to a file in NodeJS.

I have this code in my FileHandler.js:

module.exports.writeFile = function (arr) {
    var fs = require('fs');

    console.log(arr);
    var file = fs.createWriteStream(__dirname+'\\test.txt',{encoding: 'utf8'});
    file.on('error', function (err) {
        console.log(err);  });

    file.on("finish", function() {
        console.log("finished");
    });

    arr.forEach(function (item) {
        file.write(item+"\n");
    });

    file.end();
}

If I append

exports.writeFile(["1","2","3"])

To the end of this file and then run node FileHandler.js The file is created correctly.

However, if I call the writeFile function from another .js file as:

var R = require("r-script");
const dataHandler = require("./DataHandler");
const fileHandler = require("./FileHandler");

var out = R(__dirname + "\\apriori.R");

exports.getRules = function () {
    dataHandler.getListOfPageVisitsBySession(1000781912582,1530781912582,function (result){
        //ignored result variable
        fileHandler.writeFile(["1","2","3"]);
    })
}

and passing the exact same array to the function it doesn't write anything (but the file is created), neither fires err or finish event. If it matters, the DataHandler method contains a request module and a GET to another API.

Any clue of the problem?

Thanks in advance

How did you import that from another file can you show that also? — Osman Goni Nahid, Jul 05 '18 at 10:22
Did you check if the callback from `getListOfPageVisitsBySession` is running ? Try log something before you call writeFile function. — DarknessZX, Jul 05 '18 at 10:29
I just added a log before the call to writeFile and in the first line of writeFile. They both get logged. — Diogo Santos, Jul 05 '18 at 10:30
Im not sure but shouldnt you call file.end the on finish event ? — L4B0MB4, Jul 05 '18 at 10:33
Just throwing ideas here, but what OS is this? Check if you have a test.txt at your root (c:\? ) :p — ippi, Jul 05 '18 at 10:48
Windows 10. The file is created, it just stays empty. (Added this info to the main post). And, unfortunately no :( — Diogo Santos, Jul 05 '18 at 10:50
And if you do a `setTimeout(function(){console.log("done");},10000)` last? just to check if node is quitting before it gets to write anything. — ippi, Jul 05 '18 at 10:54
That was indeed the problem!! Node was quitting before writing to the file. Thank you!! — Diogo Santos, Jul 05 '18 at 10:59
https://stackoverflow.com/questions/6442676/how-to-prevent-node-js-from-exiting-while-waiting-for-a-callback — ippi, Jul 05 '18 at 11:05

Writing to file in NodeJS calling from another JS file

0 Answers0