title: puppeteer doesn't open a url without protocol
body: <pre><code>const puppeteer = require('puppeteer');
  
  const browser = await puppeteer.launch();
  const page = await browser.newPage();
  </code></pre>
  
  <p>This one works</p>
  
  <pre><code>await page.goto('https://example.com');
  </code></pre>
  
  <p>This doesn't work (without the protocol i.e http/https)</p>
  
  <pre><code>await page.goto("www.example.com');
  </code></pre>
  
  <p>It throws error</p>
  
  <blockquote>
    <p>Protocol error (Page.navigate): Cannot navigate to invalid URL</p>
  </blockquote>
  
  <p><strong>Why doesn't it append the protocol like it does when we open in Google Chrome?</strong></p>