When executing tests, each test logs the following:
WARN: 'Could not find HammerJS. Certain Angular Material components may not work correctly.'
From from Angular Material Getting Started Guide:
Some components (
mdTooltip) rely on HammerJS for gestures. In order to get the full feature-set of these components, HammerJS must be loaded into the application.
Based on that, my conclusion is that I don't need HammerJS installed as I'm not specifically using the Angular Material components that require it. If you don't need it, don't add it!
But whilst executing 1000+ tests, having that warning print out each time really isn't helpful and so I want to get rid of it or have it print once only.