How to flush the writer?

[bradvogel]

Possibly a naive question - how do you flush the writer so it writes what it has to disk? This is important as I want to write my CSV to disk periodically while processing, in case my program crashes.

[episage]

+1

[gustavosizilio]

+1

[estebgonza]

+1

[bradvogel]

Figured out the answer to my own question. You have to wait for the 'close' event on the filesystem stream:

const csvWriter = require('csv-write-stream');
const fs = require('fs');

const writer = csvWriter();
const stream = fs.createWriteStream('domains.csv');
writer.pipe(stream);

for (....) {
    writer.write({...});
}

// Close the writer.
writer.end();

// Wait for the filestream to close.
await new Promise((resolve) => {
   stream.on('close', resolve);
});

[SimeonC]

I found there's a shorter version as end takes a callback.

await new Promise((resolve) => {
  writer.end(resolve);
});

[vitaly-t]

How do you know that it is doing anything?

I would log the stream object into the console, but did not see any change in its state by adding this code.

I used:

await new Promise(resolve => csv.end(resolve));

which doesn't seem to do anything.