hook: Ignore updates to remote branches in reference-transaction

[pink]

Follow up to #879 (comment) - this PR filters out updates to remote branches from the reference-transaction hook.

Test Plan

CI and unit tests
% TEST_GIT=$(which git) TEST_GIT_EXEC_PATH=$(git --exec-path) cargo test

[pink]

Are there any additional ways I should verify this change? Also I'm getting some lint errors from git-branchless-opts but the files were untouched.

[arxanas]

Thanks! Ignore the lint failure for now. The linter runs using Rust nightly. Normally, I would just fix the issue in a separate commit, but the issue is occurring inside a macro expansion, so we can't actually fix it ourselves.

[arxanas]

Yep, this is how we destructure enums. Let's just make a few minor changes:

• Let's explicitly list out the missing cases in _. The idea is that if a new case is added, the exhaustiveness checker will make us look at this match again and update it to ensure that the logic is right.
  • Now that I think about all of the cases... let's return false for both RemoteBranch and Other. Occasionally, other tooling generates references that we also don't care about (such as git bisect or perhaps Jujutsu's keep refs).
• In this case, we can write Foo { .. } instead of Foo { field1: _, field2: _ } to ignore all fields in the enum case.
  • Actually, I don't recommend doing this in general, but the CategorizedReferenceName enum case was somewhat poorly designed. Very often we ignore the enum fields and use one of the helper methods on the type. I don't think the fields ought to have been attached to the enum cases to begin with.

[pink]

Going through and updating the failing tests for this change. Returning false for Other appears to skip processing updates to HEAD - just wanted to double check that this behavior is expected?

[arxanas]

@pink I think it's fine (although it didn't occur to me ahead of time that HEAD is an Other reference). It looks like none of the tests are failing as a result. You can update the snapshot tests manually or by using the cargo-insta tool. The HEAD reference is also tracked via the post-checkout hook, so we're not losing any data by dropping the update.

Also, I forgot to mention that you can collapse the match cases by using |:

match expr {
    Foo::Bar { .. } | Foo::Baz { .. } => false,
    Foo::Qux => true,
}

(You can do this as long as the set of variables bound in each sub-pattern is the same. Since we're using .., we're not binding any variables, so it should work.)

[arxanas]

I merged #916, so if you want to get rid of the lint errors in CI, you can try updating on top of that.