/// Return the current UTC timestamp in ISO 8601 format.
pub fn utc_now() -> String {
chrono::Utc::now().format("%Y-%m-%dT%H:%M:%SZ").to_string()
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn test_utc_now_format() {
let ts = utc_now();
assert!(ts.ends_with('Z'));
assert_eq!(ts.len(), 20);
assert_eq!(&ts[4..5], "-");
assert_eq!(&ts[7..8], "-");
assert_eq!(&ts[10..11], "T");
}
}