Add strictness flags
A number of users have requested the ability to opt in to stricter Sass compilation, in which code that would normally just causes a warning (especially a deprecation warning) instead produces a compile error. We should add these flags for all current deprecation warnings to the CLI and both APIs, and possibly add configuration file support so that the can be consistently configured for teams.
TypeScript's compiler options provide some prior art here. I suspect we don't want to add a general --strict flag that enables all strict checks, though, since this will mean some downstream users will break when we add new deprecations.
- [x] CLI support
- [x] Dart API support
- [ ] JS API support
- [ ] Documentation
As part of this, there should also be an option to error on @warn rules.
So when can we hope to see this? I'm guessing not soon, since the proposal doesn't seem to be entirely decided upon?
We have many things we want to work on and while this is one of them, we don't currently have an ETA for this. We'll add an update here when we have news to share.