feat: remove features when removing dependencies

[njelich]

When removing dependencies using the --fix flag, the features for those dependencies are not removed. This adds support for that.

I tested it manually, but tests should probably be written to make sure it works generally. From what I can see there are currently no tests for the --fix functionality anyway.

[njelich]

@bnjbvr Pending review

[bnjbvr]

Hi, as I'm working on my spare time on this project, I might not be very reactive for reviews and all of that.

That being said: how does this work? How can you guess the feature's name? (are you assuming the feature's named after the dependency?) Not sure how prevalent that usage is, so unclear whether we should do that automatically...

[njelich]

@bnjbvr I added a test case so you can see what it does. You can also add more autofix tests using the same setup.

[njelich]

In short, for a Cargo.toml with the unused log dependency:

[dependencies]
log = "0.4.14"

[features]
default = ["std"]
std = ["log/std", "other"]
other = []

It sees the log dependency is unused, and that the std feature on the log dependency is used with log/std. When removing log, it also removes the log/std feature.

[dependencies]

[features]
default = ["std"]
std = [ "other"]
other = []

[njelich]

@bnjbvr Have you had a chance to take a look at this?

[bnjbvr]

Thanks, took the time to review.

Bonus points if you switch to cargo-insta for the snapshot tests :) (but not mandatory, of course!).

[bnjbvr]

I think contains is a bit too vague here: a dependency flagged for removal called log would cause removal of a feature enabling something (a feature or another dependency) called flog.

Can you handle that better, and add a test that checks that too, please?

[bnjbvr]

Getting back to this: any idea why the CI doesn't even show up? There's no job and no way for me to approve the run or not 🤔

[bnjbvr]

I don't know why the CI job fails, but when I tried to run the tests locally by repeating the commands, they failed. Could you take another look please?

[njelich]

Will check later today