Function week_start

rust/crates/ccusage/src/summary.rs:297–311

(date: &str, start: WeekDay)

}

pub(crate) fn week_start(date: &str, start: WeekDay) -> Option<String> {
    let date = parse_iso_date(date)?;
    let start_num = match start {
        WeekDay::Sunday => 0,
        WeekDay::Monday => 1,
        WeekDay::Tuesday => 2,
        WeekDay::Wednesday => 3,
        WeekDay::Thursday => 4,
        WeekDay::Friday => 5,
        WeekDay::Saturday => 6,
    };
    let day = date.weekday_from_sunday() as i64;
    let shift = (day - start_num + 7) % 7;
    Some(format_naive_date(date.checked_add_days(-shift)?))
}

#[cfg(test)]
mod tests {