Function read_repository_format 

pub fn read_repository_format(
    context: &GitContext,
    common_dir: &Path,
) -> Result<RepositoryFormat, GitFailure>

What: Reads the format facts from the real common config file alone. Why: git config --file config --list reads only that file, so an included or worktree config never leaks into the copied format.

In TS you’d write (pseudocode):

await readRepositoryFormat({ gitPath, commonDir });