Function encode_call 

pub fn encode_call(
    serial: u32,
    target: &Target<'_>,
    arguments: &[&str],
) -> Vec<u8> 

What: The bytes of a method call with string arguments. Why: Kept apart from the socket so a test can read them back and compare them with the specification’s layout.

In TS you’d write (pseudocode):

encodeCall(serial, START_UNIT, ['cli-git.socket', 'replace'])