Function test_session_event_key_ordering

atomic-core/src/change/session.rs:785–813

()

    #[test]
    fn test_session_event_key_ordering() {
        // Keys for the same provenance_id must sort by seq in lexicographic
        // (B-tree) order across the full u64 range.  Big-endian encoding
        // guarantees this: the most-significant byte comes first, so byte-wise
        // comparison matches numeric comparison for all values.
        let k1 = encode_session_event_key(5, 0);
        let k2 = encode_session_event_key(5, 1);
        let k3 = encode_session_event_key(5, 100);
        let k4 = encode_session_event_key(6, 0);

        assert!(k1 < k2);
        assert!(k2 < k3);
        assert!(k3 < k4, "different provenance_id sorts after");

        // Boundary: seq=255 (single-byte max) vs seq=256 (spills into second byte).
        // With big-endian encoding this must sort correctly.
        let k_255 = encode_session_event_key(5, 255);
        let k_256 = encode_session_event_key(5, 256);
        assert!(
            k_255 < k_256,
            "seq=255 must sort before seq=256 (byte-spill boundary)"
        );

        // seq=256 on provenance_id=5 must still sort before provenance_id=6.
        assert!(
            k_256 < k4,
            "seq=256 on provenance_id=5 must sort before provenance_id=6"
        );
    }

    #[test]
    fn test_session_todo_key_deterministic() {