mod diff {    use crate::named_repo;    use git_object::bstr::ByteSlice;    use git_object::tree::EntryMode;    use git_repository as git;    use git_repository::object::tree::diff::change::Event;    use std::convert::Infallible;     #[test]    fn changes_against_tree_modified() {        let repo = named_repo("make_diff_repo.sh").unwrap();        let from = tree_named(&repo, "@^{/c3}~1");        let to = tree_named(&repo, ":/c3");        from.changes()            .for_each_to_obtain_tree(&to, |change| -> Result<_, Infallible> {                assert_eq!(change.location, "", "without configuration the location field is empty");                match change.event {                    Event::Modification {                        previous_entry_mode,                        previous_id,                        entry_mode,                        id,                    } => {                        assert_eq!(previous_entry_mode, EntryMode::Blob);                        assert_eq!(entry_mode, EntryMode::Blob);                        assert_eq!(previous_id.object().unwrap().data.as_bstr(), "a\n");                        assert_eq!(id.object().unwrap().data.as_bstr(), "a\na1\n");                    }                    Event::Deletion { .. } | Event::Addition { .. } => unreachable!("only modification is expected"),                };                 let count = change                    .event                    .diff()                    .expect("changed file")                    .expect("objects available")                    .text(git::diff::lines::Algorithm::Myers)                    .iter_all_changes()                    .count();                assert_eq!(count, 2);                Ok(Default::default())            })            .unwrap();    }     #[test]    fn changes_against_tree_with_filename_tracking() {        let repo = named_repo("make_diff_repo.sh").unwrap();        let from = tree_named(            &repo,            &git::hash::ObjectId::empty_tree(git::hash::Kind::Sha1).to_string(),        );        let to = tree_named(&repo, ":/c1");         let mut expected = vec!["a", "b", "c", "d"];        from.changes()            .track_filename()            .for_each_to_obtain_tree(&to, |change| -> Result<_, Infallible> {                expected.retain(|name| name != change.location);                Ok(Default::default())            })            .unwrap();        assert_eq!(expected, Vec::<&str>::new(), "all paths should have been seen");         let mut expected = vec!["a", "b", "dir/c", "d"];        from.changes()            .track_path()            .for_each_to_obtain_tree(&to, |change| -> Result<_, Infallible> {                expected.retain(|name| name != change.location);                Ok(Default::default())            })            .unwrap();        assert_eq!(expected, Vec::<&str>::new(), "all paths should have been seen");    }     fn tree_named<'repo>(repo: &'repo git::Repository, rev_spec: &str) -> git::Tree<'repo> {        repo.rev_parse_single(rev_spec)            .unwrap()            .object()            .unwrap()            .peel_to_kind(git::object::Kind::Tree)            .unwrap()            .into_tree()    }}