Function atomic_push 

pub fn atomic_push(
    arguments: &[OsString],
    wrapper_flags: &[&[u8]],
) -> Result<ArgumentRewrite, OptionError>

What: Decide the transform for one command line. Result<A, B> is “either success A or failure B”; &[&[u8]] borrows the caller’s wrapper-only spellings. Why: The flag goes immediately after push, so global options before it survive. Gotcha: Err means Git 2.56.0 itself refuses the push options; the caller forwards such a command unchanged so Git prints its own error.

In TS you’d write (pseudocode):

function atomicPush(args: readonly string[]): readonly string[];