Merge #88: Add tests to TorrentEntry

8d268b0 test: add tests to TorrentEntry (Jose Celano)

Pull request description:

  I've added some tests to the `TorrentEntry`. I've not done any refactor. I've proposed some in the PR comments.

ACKs for top commit:
  josecelano:
    ACK 8d268b0

Tree-SHA512: 4c99dae95521e6a9b5822fc977dacde8f6dc7e1277cad095cbf515a82ff59197469285fbcbc4702bf3e7f6fe263e72e32c76bdba858082f47adc0e5e6f37a4a2

src/tracker/torrent.rs

@@ -98,3 +98,272 @@ pub enum TorrentError {
     CouldNotSendResponse,
     InvalidInfoHash,
 }
+
+#[cfg(test)]
+mod tests {
+    use std::{
+        net::{IpAddr, Ipv4Addr, SocketAddr},
+        ops::Sub,
+        time::Duration,
+    };
+
+    use aquatic_udp_protocol::{AnnounceEvent, NumberOfBytes};
+
+    use crate::{
+        peer::TorrentPeer,
+        protocol::clock::{DefaultClock, DurationSinceUnixEpoch, StoppedClock, StoppedTime, Time, WorkingClock},
+        torrent::TorrentEntry,
+        PeerId,
+    };
+
+    struct TorrentPeerBuilder {
+        peer: TorrentPeer,
+    }
+
+    impl TorrentPeerBuilder {
+        pub fn default() -> TorrentPeerBuilder {
+            let default_peer = TorrentPeer {
+                peer_id: PeerId([0u8; 20]),
+                peer_addr: SocketAddr::new(IpAddr::V4(Ipv4Addr::new(127, 0, 0, 1)), 8080),
+                updated: DefaultClock::now(),
+                uploaded: NumberOfBytes(0),
+                downloaded: NumberOfBytes(0),
+                left: NumberOfBytes(0),
+                event: AnnounceEvent::Started,
+            };
+            TorrentPeerBuilder { peer: default_peer }
+        }
+
+        pub fn with_event_completed(mut self) -> Self {
+            self.peer.event = AnnounceEvent::Completed;
+            self
+        }
+
+        pub fn with_peer_address(mut self, peer_addr: SocketAddr) -> Self {
+            self.peer.peer_addr = peer_addr;
+            self
+        }
+
+        pub fn with_peer_id(mut self, peer_id: PeerId) -> Self {
+            self.peer.peer_id = peer_id;
+            self
+        }
+
+        pub fn with_number_of_bytes_left(mut self, left: i64) -> Self {
+            self.peer.left = NumberOfBytes(left);
+            self
+        }
+
+        pub fn updated_at(mut self, updated: DurationSinceUnixEpoch) -> Self {
+            self.peer.updated = updated;
+            self
+        }
+
+        pub fn into(self) -> TorrentPeer {
+            self.peer
+        }
+    }
+
+    /// A torrent seeder is a peer with 0 bytes left to download which
+    /// has not announced it has stopped
+    fn a_torrent_seeder() -> TorrentPeer {
+        TorrentPeerBuilder::default()
+            .with_number_of_bytes_left(0)
+            .with_event_completed()
+            .into()
+    }
+
+    /// A torrent leecher is a peer that is not a seeder.
+    /// Leecher: left > 0 OR event = Stopped
+    fn a_torrent_leecher() -> TorrentPeer {
+        TorrentPeerBuilder::default()
+            .with_number_of_bytes_left(1)
+            .with_event_completed()
+            .into()
+    }
+
+    #[test]
+    fn the_default_torrent_entry_should_contain_an_empty_list_of_peers() {
+        let torrent_entry = TorrentEntry::new();
+
+        assert_eq!(torrent_entry.get_peers(None).len(), 0);
+    }
+
+    #[test]
+    fn a_new_peer_can_be_added_to_a_torrent_entry() {
+        let mut torrent_entry = TorrentEntry::new();
+        let torrent_peer = TorrentPeerBuilder::default().into();
+
+        torrent_entry.update_peer(&torrent_peer); // Add the peer
+
+        assert_eq!(*torrent_entry.get_peers(None)[0], torrent_peer);
+        assert_eq!(torrent_entry.get_peers(None).len(), 1);
+    }
+
+    #[test]
+    fn a_torrent_entry_should_contain_the_list_of_peers_that_were_added_to_the_torrent() {
+        let mut torrent_entry = TorrentEntry::new();
+        let torrent_peer = TorrentPeerBuilder::default().into();
+
+        torrent_entry.update_peer(&torrent_peer); // Add the peer
+
+        assert_eq!(torrent_entry.get_peers(None), vec![&torrent_peer]);
+    }
+
+    #[test]
+    fn a_peer_can_be_updated_in_a_torrent_entry() {
+        let mut torrent_entry = TorrentEntry::new();
+        let mut torrent_peer = TorrentPeerBuilder::default().into();
+        torrent_entry.update_peer(&torrent_peer); // Add the peer
+
+        torrent_peer.event = AnnounceEvent::Completed; // Update the peer
+        torrent_entry.update_peer(&torrent_peer); // Update the peer in the torrent entry
+
+        assert_eq!(torrent_entry.get_peers(None)[0].event, AnnounceEvent::Completed);
+    }
+
+    #[test]
+    fn a_peer_should_be_removed_from_a_torrent_entry_when_the_peer_announces_it_has_stopped() {
+        let mut torrent_entry = TorrentEntry::new();
+        let mut torrent_peer = TorrentPeerBuilder::default().into();
+        torrent_entry.update_peer(&torrent_peer); // Add the peer
+
+        torrent_peer.event = AnnounceEvent::Stopped; // Update the peer
+        torrent_entry.update_peer(&torrent_peer); // Update the peer in the torrent entry
+
+        assert_eq!(torrent_entry.get_peers(None).len(), 0);
+    }
+
+    #[test]
+    fn torrent_stats_change_when_a_previously_known_peer_announces_it_has_completed_the_torrent() {
+        let mut torrent_entry = TorrentEntry::new();
+        let mut torrent_peer = TorrentPeerBuilder::default().into();
+
+        torrent_entry.update_peer(&torrent_peer); // Add the peer
+
+        torrent_peer.event = AnnounceEvent::Completed; // Update the peer
+        let stats_have_changed = torrent_entry.update_peer(&torrent_peer); // Update the peer in the torrent entry
+
+        assert!(stats_have_changed);
+    }
+
+    #[test]
+    fn torrent_stats_should_not_change_when_a_peer_announces_it_has_completed_the_torrent_if_it_is_the_first_announce_from_the_peer(
+    ) {
+        let mut torrent_entry = TorrentEntry::new();
+        let torrent_peer_announcing_complete_event = TorrentPeerBuilder::default().with_event_completed().into();
+
+        // Add a peer that did not exist before in the entry
+        let torrent_stats_have_not_changed = !torrent_entry.update_peer(&torrent_peer_announcing_complete_event);
+
+        assert!(torrent_stats_have_not_changed);
+    }
+
+    #[test]
+    fn a_torrent_entry_could_filter_out_peers_with_a_given_socket_address() {
+        let mut torrent_entry = TorrentEntry::new();
+        let peer_socket_address = SocketAddr::new(IpAddr::V4(Ipv4Addr::new(127, 0, 0, 1)), 8080);
+        let torrent_peer = TorrentPeerBuilder::default().with_peer_address(peer_socket_address).into();
+        torrent_entry.update_peer(&torrent_peer); // Add peer
+
+        // Get peers excluding the one we have just added
+        let peers = torrent_entry.get_peers(Some(&peer_socket_address));
+
+        assert_eq!(peers.len(), 0);
+    }
+
+    fn peer_id_from_i32(number: i32) -> PeerId {
+        let peer_id = number.to_le_bytes();
+        PeerId([
+            0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, 0u8, peer_id[0], peer_id[1], peer_id[2],
+            peer_id[3],
+        ])
+    }
+
+    #[test]
+    fn the_tracker_should_limit_the_list_of_peers_to_74_when_clients_scrape_torrents() {
+        let mut torrent_entry = TorrentEntry::new();
+
+        // We add one more peer than the scrape limit
+        for peer_number in 1..=74 + 1 {
+            let torrent_peer = TorrentPeerBuilder::default()
+                .with_peer_id(peer_id_from_i32(peer_number))
+                .into();
+            torrent_entry.update_peer(&torrent_peer);
+        }
+
+        let peers = torrent_entry.get_peers(None);
+
+        assert_eq!(peers.len(), 74)
+    }
+
+    #[test]
+    fn torrent_stats_should_have_the_number_of_seeders_for_a_torrent() {
+        let mut torrent_entry = TorrentEntry::new();
+        let torrent_seeder = a_torrent_seeder();
+
+        torrent_entry.update_peer(&torrent_seeder); // Add seeder
+
+        assert_eq!(torrent_entry.get_stats().0, 1);
+    }
+
+    #[test]
+    fn torrent_stats_should_have_the_number_of_leechers_for_a_torrent() {
+        let mut torrent_entry = TorrentEntry::new();
+        let torrent_leecher = a_torrent_leecher();
+
+        torrent_entry.update_peer(&torrent_leecher); // Add leecher
+
+        assert_eq!(torrent_entry.get_stats().2, 1);
+    }
+
+    #[test]
+    fn torrent_stats_should_have_the_number_of_peers_that_having_announced_at_least_two_events_the_latest_one_is_the_completed_event(
+    ) {
+        let mut torrent_entry = TorrentEntry::new();
+        let mut torrent_peer = TorrentPeerBuilder::default().into();
+        torrent_entry.update_peer(&torrent_peer); // Add the peer
+
+        // Announce "Completed" torrent download event.
+        torrent_peer.event = AnnounceEvent::Completed;
+        torrent_entry.update_peer(&torrent_peer); // Update the peer
+
+        let number_of_previously_known_peers_with_completed_torrent = torrent_entry.get_stats().1;
+
+        assert_eq!(number_of_previously_known_peers_with_completed_torrent, 1);
+    }
+
+    #[test]
+    fn torrent_stats_should_not_include_a_peer_in_the_completed_counter_if_the_peer_has_announced_only_one_event() {
+        let mut torrent_entry = TorrentEntry::new();
+        let torrent_peer_announcing_complete_event = TorrentPeerBuilder::default().with_event_completed().into();
+
+        // Announce "Completed" torrent download event.
+        // It's the first event announced from this peer.
+        torrent_entry.update_peer(&torrent_peer_announcing_complete_event); // Add the peer
+
+        let number_of_peers_with_completed_torrent = torrent_entry.get_stats().1;
+
+        assert_eq!(number_of_peers_with_completed_torrent, 0);
+    }
+
+    #[test]
+    fn a_torrent_entry_should_remove_a_peer_not_updated_after_a_timeout_in_seconds() {
+        let mut torrent_entry = TorrentEntry::new();
+
+        let timeout = 120u32;
+
+        let now = WorkingClock::now();
+        StoppedClock::local_set(&now);
+
+        let timeout_seconds_before_now = now.sub(Duration::from_secs(timeout as u64));
+        let inactive_peer = TorrentPeerBuilder::default()
+            .updated_at(timeout_seconds_before_now.sub(Duration::from_secs(1)))
+            .into();
+        torrent_entry.update_peer(&inactive_peer); // Add the peer
+
+        torrent_entry.remove_inactive_peers(timeout);
+
+        assert_eq!(torrent_entry.peers.len(), 0);
+    }
+}