Function wait_until_done 

pub fn wait_until_done(
    child: &mut Child,
    outputs: &[&File],
    deadline: Duration,
) -> Result<Result<ExitStatus, StopCause>, SingleFlightError>

What: Look at a running push until it ends, its deadline passes or its output floods. Why: std has no timed wait, so the parent looks with try_wait, which never blocks.

In TS you’d write (pseudocode):

await Promise.race([exited, deadline, flood]);