Rename --all to --workspace?

[lnicola]

In rust-lang/cargo#7241, cargo --all got deprecated in favor of --workspace. There's less chance of confusion in cargo fmt because there is no `--all-targets, but perhaps it's a good idea to support both for consistency.

[calebcartwright]

Thanks @lnicola, I wasn't aware of the change to --workspace in cargo! There's certainly a case to be made for consistency, and this would be as good a time as any as the current focus is on rustfmt 2.0 and there's other arg/option changes. There are, however, certain behaviors associated with cargo fmt's args that IMO are worth considering.

For example, when running cargo fmt in the root directory of a workspace, cargo fmt already formats all of the workspace members. Running cargo fmt --all formats the workspace plus any local/path based dependencies of the packages in that workspace, regardless of whether those local deps are explicit workspace members.

If the format strategy currently used with --all were renamed to --workspace, would it be confusing/surprising for users that their entire workspace gets formatted when they run cargo fmt even without the --workspace arg? Similarly, would it be confusing/surprising for users when running cargo fmt --workspace that those local/deps outside the workspace were formatted?

[lnicola]

Sorry, I wasn't aware of what --all did. I went by the help message:

--all Format all packages (only usable in workspaces)

So I hope you understand my confusion. If it really behaves like you described, I don't think it's worth making any change here.

[calebcartwright]

No worries! It may still be worth considering a rename, but I just wanted to note some of the other aspects that would need to be weighed against the consistency with cargo's --workspace

I can see how that message could be confusing, especially that suffix. I believe --all can technically be used today even outside an explicit workspace so we should probably update that message either way. Perhaps something like the below would be more clear?

--all Format all packages and their local path-based dependencies

[topecongiro]

@calebcartwright Seems good to me 🙌

[lnicola]

Filed #3914.