node.js - How to download file with puppeteer using headless: true?

Question

I've been running the following code in order to download a csv file from the website http://niftyindices.com/resources/holiday-calendar:

const puppeteer = require('puppeteer');

(async () => {
const browser = await puppeteer.launch({headless: true});
const page = await browser.newPage();

await page.goto('http://niftyindices.com/resources/holiday-calendar');
await page._client.send('Page.setDownloadBehavior', {behavior: 'allow', 
downloadPath: '/tmp'})
await page.click('#exportholidaycalender');
await page.waitFor(5000);
await browser.close();
})();

with headless: false it works, it downloads the file into /Users/user/Downloads. with headless: true it does NOT work.

I'm running this on a macOS Sierra (MacBook Pro) using puppeteer version 1.1.1 which pulls Chromium version 66.0.3347.0 into .local-chromium/ directory and used npm init and npm i --save puppeteer to set it up.

Any idea whats wrong?

Thanks in advance for your time and help,

Answer 1

I spent hours poring through this thread and Stack Overflow yesterday, trying to figure out how to get Puppeteer to download a csv file by clicking a download link in headless mode in an authenticated session. The accepted answer here didn't work in my case because the download does not trigger targetcreated, and the next answer, for whatever reason, did not retain the authenticated session. This article saved the day. In short, fetch. Hopefully this helps someone else out.

const res = await this.page.evaluate(() =>
{
    return fetch('https://example.com/path/to/file.csv', {
        method: 'GET',
        credentials: 'include'
    }).then(r => r.text());
});