close browser && page.txt

close browser && page

      // page.on('targetcreated', async target => {
      //   const pageTarget = await target.page()
      //   /* close the session */
      //   page.close()
      //   pageTarget.close()
      // })

      for (const page of await this.browser.pages()) {
        await page.close({
          'runBeforeUnload': true
        })
      }
      await this.browser.close()

----------------------------------

      //save target of original page to know that this was the opener:
      // const pageTarget = page.target()
      //execute click on first tab that triggers opening of new tab:
      // await page.click('#selector')
      //check that the first page opened this new page:
      // const newTarget = await browser.waitForTarget(target => target.opener() === pageTarget)
      //get the new page object:
      // const newPage = await newTarget.page()
      // if (newPage) newPage.close()

----------------------

const puppeteer = require('puppeteer');

(async () => {
  const browser = await puppeteer.launch();
  const [page] = await browser.pages();
  browser.on('targetdestroyed', async () => console.log('Target destroyed. Pages count: ' + (await browser.pages()).length));
  console.log('closing page...');
  await page.close();
  console.log('page closed.');
  await browser.close();
})();

--------------------------------

It's hard without knowing your conditions when the app opens a new tab. It works perfectly fine for me. Here is a code demonstrating how I can use it. Read the comments to understand the steps.

UPDATED:

window.open() doesn't return a promise, thus browser.pages() is executed faster than the browser can create and report the event. We can use the targetcreated event to know if any new tab is created.

browser.on('targetcreated', function(){
    console.log('New Tab Created');
})
If you wait for a while or return a promise, you will see it reports it within browser.pages() count.

await tabOne.evaluate(() => {
    window.open('http://www.example.com', '_blank');
  });
await tabOne.waitFor(2000); // await for a while
console.log("current page count ", (await browser.pages()).length); // 3
Here is the final code.

const puppeteer = require('puppeteer');

(async () => {
  const browser = await puppeteer.launch();

  browser.on('targetcreated', function(){
    console.log('New Tab Created');
  })

  // get current tab count
  console.log("current page count ", (await browser.pages()).length); // 3

  // create a new tab
  await browser.newPage();
  // lets see if tab increased
  console.log("current page count ", (await browser.pages()).length); // 3

  // use destructuring for easier usage
  const [tabOne, tabTwo] = (await browser.pages());

  // use the tabs aka Page objects properly
  await tabOne.goto('https://example.com');
  console.log("Tab One Title ",await tabOne.title()); // Example Domain

  // use the tabs aka Page objects properly
  await tabTwo.goto('https://example.com');
  console.log("Tab Two Title ",await tabTwo.title()); // Example Domain

  await tabOne.evaluate(() => {
    window.open('http://www.example.com', '_blank');
  });
  await tabOne.waitFor(2000); // wait for a while
  console.log("current page count ", (await browser.pages()).length); // 3

  // close the browser
  await browser.close();
})();
If you run it, you'll get the result in following sequence.

/*
current page count  1
New Tab Created
current page count  2
Tab One Title  Example Domain
Tab Two Title  Example Domain
New Tab Created
current page count  3
*/