Now, we have enough information to build a solid testing strategy for responsive visualizations. Note that this is a very opinionated setup based on my experience, and feel free to exchange any layer or tool with your favorite ones. However, keep the general ideas for your workflow.
First, we will use the Chrome browser on the desktop PC while developing. We either use a normal desktop window or we switch to a mobile view in the device mode. This depends on the target screen size and resolution. Personally, I prefer to work in a desktop Chrome and debug and test on mobiles.
While developing, we need to regularly do some manual testing to make sure our visualization looks and feels nice. Running emulators for different operating systems locally is a pain; that's why I prefer syncing a real mobile phone and a tablet via Browsersync to my current Chrome window. If you don't have access to real devices, you can also use Browserstack on your local project.