Add database implementation of channel message change tracking

crates/collab/src/db/tests/message_tests.rs

@@ -57,3 +57,142 @@ async fn test_channel_message_nonces(db: &Arc<Database>) {
     assert_eq!(msg1_id, msg3_id);
     assert_eq!(msg2_id, msg4_id);
 }
+
+test_both_dbs!(
+    test_channel_message_new_notification,
+    test_channel_message_new_notification_postgres,
+    test_channel_message_new_notification_sqlite
+);
+
+async fn test_channel_message_new_notification(db: &Arc<Database>) {
+    let user_a = db
+        .create_user(
+            "user_a@example.com",
+            false,
+            NewUserParams {
+                github_login: "user_a".into(),
+                github_user_id: 1,
+                invite_count: 0,
+            },
+        )
+        .await
+        .unwrap()
+        .user_id;
+    let user_b = db
+        .create_user(
+            "user_b@example.com",
+            false,
+            NewUserParams {
+                github_login: "user_b".into(),
+                github_user_id: 1,
+                invite_count: 0,
+            },
+        )
+        .await
+        .unwrap()
+        .user_id;
+
+    let channel = db
+        .create_channel("channel", None, "room", user_a)
+        .await
+        .unwrap();
+
+    db.invite_channel_member(channel, user_b, user_a, false)
+        .await
+        .unwrap();
+
+    db.respond_to_channel_invite(channel, user_b, true)
+        .await
+        .unwrap();
+
+    let owner_id = db.create_server("test").await.unwrap().0 as u32;
+
+    // Zero case: no messages at all
+    assert!(!db.has_new_message_tx(channel, user_b).await.unwrap());
+
+    let a_connection_id = rpc::ConnectionId { owner_id, id: 0 };
+    db.join_channel_chat(channel, a_connection_id, user_a)
+        .await
+        .unwrap();
+
+    let _ = db
+        .create_channel_message(channel, user_a, "1", OffsetDateTime::now_utc(), 1)
+        .await
+        .unwrap();
+
+    let (second_message, _) = db
+        .create_channel_message(channel, user_a, "2", OffsetDateTime::now_utc(), 2)
+        .await
+        .unwrap();
+
+    let _ = db
+        .create_channel_message(channel, user_a, "3", OffsetDateTime::now_utc(), 3)
+        .await
+        .unwrap();
+
+    // Smoke test: can we detect a new message?
+    assert!(db.has_new_message_tx(channel, user_b).await.unwrap());
+
+    let b_connection_id = rpc::ConnectionId { owner_id, id: 1 };
+    db.join_channel_chat(channel, b_connection_id, user_b)
+        .await
+        .unwrap();
+
+    // Joining the channel should _not_ update us to the latest message
+    assert!(db.has_new_message_tx(channel, user_b).await.unwrap());
+
+    // Reading the earlier messages should not change that we have new messages
+    let _ = db
+        .get_channel_messages(channel, user_b, 1, Some(second_message))
+        .await
+        .unwrap();
+
+    assert!(db.has_new_message_tx(channel, user_b).await.unwrap());
+
+    // This constraint is currently inexpressible, creating a message implicitly broadcasts
+    // it to all participants
+    //
+    // Creating new messages when we haven't read the latest one should not change the flag
+    // let _ = db
+    //     .create_channel_message(channel, user_a, "4", OffsetDateTime::now_utc(), 4)
+    //     .await
+    //     .unwrap();
+    // assert!(db.has_new_message_tx(channel, user_b).await.unwrap());
+
+    // But reading the latest message should clear the flag
+    let _ = db
+        .get_channel_messages(channel, user_b, 4, None)
+        .await
+        .unwrap();
+
+    assert!(!db.has_new_message_tx(channel, user_b).await.unwrap());
+
+    // And future messages should not reset the flag
+    let _ = db
+        .create_channel_message(channel, user_a, "5", OffsetDateTime::now_utc(), 5)
+        .await
+        .unwrap();
+
+    assert!(!db.has_new_message_tx(channel, user_b).await.unwrap());
+
+    let _ = db
+        .create_channel_message(channel, user_b, "6", OffsetDateTime::now_utc(), 6)
+        .await
+        .unwrap();
+
+    assert!(!db.has_new_message_tx(channel, user_b).await.unwrap());
+
+    // And we should start seeing the flag again after we've left the channel
+    db.leave_channel_chat(channel, b_connection_id, user_b)
+        .await
+        .unwrap();
+
+    assert!(!db.has_new_message_tx(channel, user_b).await.unwrap());
+
+    let _ = db
+        .create_channel_message(channel, user_a, "7", OffsetDateTime::now_utc(), 7)
+        .await
+        .unwrap();
+
+    assert!(db.has_new_message_tx(channel, user_b).await.unwrap());
+}