Function private_invocation 

pub fn private_invocation(
    arguments: &[OsString],
    pathspecs: &[String],
    mode: TransactionMode,
    staged_all: bool,
) -> (Vec<String>, Vec<String>)

What: The kept global options and the commit options of the arguments, with the pathspecs and the selection options the private index already holds removed. Why: Real git commit must commit the private index as it stands, so it is given neither the paths nor -a.

In TS you’d write (pseudocode):

privateInvocation({ arguments, pathspecs, mode, stagedAll })