Provide an example for signed commits

[davinkevin]

Hello 👋

Thank you for the project, it has been very helpful to understand how to do things with git2-rs.

However, I struggled to use the function commit, especially for signed commits. I searched for example, but no example or test so far.

My problem was related to transform the result of UserSign::from_config(&repo, &repo.config()?) into the expected parameter of the commit function, which has to be of type Option<&dyn Sign>.

let signer = UserSign::from_config(&repo, &repo.config()?)
    .ok()
    .as_ref();

let new_oid = commit(
    &repo,
    &commit.author(),
    &commit.committer(),
    &message[..],
    &commit.tree()?,
    &[&repo.find_commit(parent_oid.unwrap_or(first_parent))?],
    signer
)?;

And with that, and many other tries, always a compiler error.

I found many things (example), but nothing trivial as the library is, so I prefer opening an issue in case of an error in the original code.

I just ask for a test or an example of this code.

Thank you!

[epage]

I do

self.sign.as_ref().map(|s| s as &dyn git2_ext::ops::Sign)

See https://github.com/gitext-rs/git-stack/blob/f42093a0d6f77744195f23de47617f65d80e2b60/src/git/repo.rs#L423C13-L423C70

Would appreciate examples being added but likely not going to get to it myself for some time.

[davinkevin]

Thank you for the example @epage!

I solved my issue by doing this:

let signer = UserSign::from_config(&repo, &repo.config()?);
let sign = signer
    .as_ref()
    .map(|s| s as &dyn Sign)
    .ok();

let oid = extCommit(
    &repo,
    &author,
    &committer,
    &message,
    &tree,
    &parent_refs[..],
    sign,
)?;

The missing part was the first let, which can't be inlined with the second one, because of the borrow checker (I'm kind of n00b in rust).