Function update_scope 

pub fn update_scope(
    git: &PushGit,
    update: &PushUpdate,
    published: &[String],
) -> Result<UpdateScope, ManualPushRangeError>

What: The scope of one update, from its local object and the published tips of its remote. Why: rev-list names exactly the commits the remote lacks, so a scan never repeats published history.

In TS you’d write (pseudocode):

async function scopeOf(update, publishedTips): Promise<UpdateScope>;