Function run_process 

pub fn run_process(
    arguments: &[OsString],
    environment: &[(OsString, OsString)],
) -> i32

What: Run one invocation with the real process facts and return its exit code. i32 is a signed 32-bit integer, the type of process exit codes. Returns only when Git was not started; a forwarded command never returns. Why: This is everything the executable’s main does; keeping it in the library lets the same code be measured by tests and mutation runs.

In TS you’d write (pseudocode):

function runProcess(args: string[], environment: [string, string][]): number;