Function changed_paths 

pub fn changed_paths(
    context: &GitContext,
    root: &Path,
) -> Result<ChangedPaths, String>

What: The paths git status lists as changed or untracked in the worktree at root, counted, with the first, and whether a .gitattributes file is among them (also one inside an untracked directory); or the words that say which Git run failed and how. Why: Only Git’s own status tells a real change from a stale record of file times. The read takes no optional lock, so it never disturbs the checkout a person works in. A listing with nothing in it is an answer (every file equals its commit by content), never a failure: the stat data of an index that was just written, or of a file that was touched, proves nothing, and Git settles those by content.

In TS you’d write (pseudocode):

const changed = await changedPaths(context, root); // throws the reason Git could not say