Automatically add featureFlags.future flags to the configuration files whenever the init command is ran

[dextermb]

This PR implements the --future flag on the init command which then automatically fill-in and enables the current featureFlags.future.

This PR implements adding commented out featureFlags.future flags whenever init commend is ran. This could be expanded to fill out all sorts of data and remove the manual processes that once were.

This was previously mentioned in my previous PR (#2372) but I thought I'd take a shot at implementing it myself! Feedback welcome.

✅ Tests updated and passed
✅ Styles updated and passed

[adamwathan]

Hey thanks for this! I am not 100% convinced we need to add a --future option that auto-enables all future flags but I would love if we could at least reuse a bunch of the work you've done here to automatically fill in the future key with the commented out future flags, so we don't have to keep that up to date manually.

Would you be open to modifying this PR to eliminate the --future option and instead just always add all future options but commented out, and in a programmatic way that avoids us needing to keep it in sync manually?

[dextermb]

Would you be open to modifying this PR to eliminate the --future option and instead just always add all future options but commented out, and in a programmatic way that avoids us needing to keep it in sync manually?

Sure. I'll see if I can do that!

[dextermb]

@adamwathan I've implemented this based on your suggestion above. I was also thinking we could do this with the experimental flags, but I wasn't sure if you wanted it in the same PR or not.

Perhaps a PR title change would make sense.

[adamwathan]

Awesome, thank you!

[adamwathan]

Just a heads up, I need to revert this because it completely breaks tailwindcss init --full. By converting the config to JSON you lose all of the functions in the config file. The tests would have told you this but you changed them to stop comparing the output and just check if the file exists, which is why I didn't notice this :/

Next time please don't just change the test when you see it fail, make it pass instead :)

[dextermb]

The tests would have told you this but you changed them to stop comparing the output and just check if the file exists, which is why I didn't notice this :/

Next time please don't just change the test when you see it fail, make it pass instead :)

Hey! Sorry, I wasn't aware of the full content within the complete config. I ended up changing to checking that the file exists as I couldn't figure out a nice way to generate the file with the automatically added future flags.

I suppose it would still output as true due to the conversion step when outputting the file content. Whoops!