This recipe provides a strategy for automatically loading a web page at different viewport sizes, capturing screenshots at each size, and thus testing our responsive design's breakpoints.
To run this recipe, we will need a script that accesses a web page; the target URL will need to be a responsive design with several breakpoints or viewport targets that we want to test. We also need write permissions to the filesystem in the script's working directory.
The script in this recipe is available in the downloadable code repository as
chapter07. If we run the provided example script, we must change to the root directory for the book's sample code.
Lastly, the script in this recipe ...