Thank you. This really helps with the developer experience.
Which as we know has improved dramatically with.gjs over widgets.
however
There are lots of very odd errors you can get when using gjs components that do not make finding the issues very easy.
For example, lets mess up the helper name:
{{html_safe this.bannerTextContent}}
Leads to the classic:
program.js:100 Uncaught (in promise) TypeError: Invalid value used as weak map key at WeakMap.set (<anonymous>)
(this also happens here with a valid name if you forget the import)
Say what?! 
There are lots of these examples.
I guess this is a downside of using a framework?