Scraping pages

We call the action of extracting data from web pages web scraping. Scraping is useful for a variety of use cases:

  1. In testing and monitoring, asserting against the state of one or more elements on a page
  2. In general, gathering data for a variety of different purposes

# Scraping element attributes & properties

Below is an example running against our test site, getting and printing out the href attribute of the first a element on the homepage. That just happens to be our logo, which links right back to our homepage, and therefore will have an href value equal to the URL we navigate to using page.goto():

    As an alternative, it is also possible to retrieve an ElementHandle and then retrieve a property value from it. Following is an example printing the href value of the first a element of our homepage:

      TIP

      The innerText property is often used in tests to assert that some element on the page contains the expected text.

      # Scraping lists of elements

      Scraping element lists is just as easy. For example, let's grab the innerText of each product category shown on the homepage:

        # Scraping images

        Scraping images from a page is also possible. For example, we can easily get the logo of our test website and save it as a file:

          We are using axios to make a GET request against the source URL of the image. The response body will contain the image itself, which can be written to a file using fs.

          # Generating JSON from scraping

          Once we start scraping more information, we might want to have it stored in a standard format for later use. Let's gather the title, author and price from each book that appears on the home page of our test site:

          books with titles ready for scraping

          The code for that could look like this:

            The resulting books.json file will look like the following:

            [
              { "title": "Haben oder haben",
                "author": "Fric Eromm",
                "price": "$9.95"
              },
              { 
                "title": "Parry Hotter",
                "author": "J/K Rowlin'",
                "price": "$9.95"
              },
              {
                "title": "Laughterhouse-Five",
                "author": "Truk Tugennov",
                "price": "$9.95"
              },
              {
                "title": "To Mock a Killingbird",
                "author": "Larper Hee",
                "price": "$9.95"
              },
              ...
            ]
            
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            All the above examples can be run as follows:

              # Further reading

              1. Puppeteer's and Playwright's official API reference on the topic
              2. An E2E example test asserting agains an element's innerText
              3. An excellent introduction to scraping with Puppeteer by Nick Chikovani
              4. A practical tutorial on web scraping with Puppeteer by Kartik Singh