nats adapter

crates/adapters/nats/src/subject.rs

@@ -0,0 +1,76 @@
+use domain::events::DomainEvent;
+
+pub fn event_to_subject(prefix: &str, event: &DomainEvent) -> String {
+    let suffix = match event {
+        DomainEvent::ReviewLogged { .. }    => "review.logged",
+        DomainEvent::ReviewUpdated { .. }   => "review.updated",
+        DomainEvent::MovieDiscovered { .. } => "movie.discovered",
+    };
+    format!("{prefix}.{suffix}")
+}
+
+pub fn consumer_subject_filter(prefix: &str) -> String {
+    format!("{prefix}.>")
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use chrono::NaiveDateTime;
+    use domain::value_objects::{ExternalMetadataId, MovieId, Rating, ReviewId, UserId};
+    use uuid::Uuid;
+
+    fn dt() -> NaiveDateTime {
+        chrono::DateTime::from_timestamp(1_700_000_000, 0).unwrap().naive_utc()
+    }
+
+    #[test]
+    fn review_logged_subject() {
+        let event = DomainEvent::ReviewLogged {
+            review_id: ReviewId::from_uuid(Uuid::new_v4()),
+            movie_id: MovieId::from_uuid(Uuid::new_v4()),
+            user_id: UserId::from_uuid(Uuid::new_v4()),
+            rating: Rating::new(3).unwrap(),
+            watched_at: dt(),
+        };
+        assert_eq!(
+            event_to_subject("movies-diary.events", &event),
+            "movies-diary.events.review.logged"
+        );
+    }
+
+    #[test]
+    fn review_updated_subject() {
+        let event = DomainEvent::ReviewUpdated {
+            review_id: ReviewId::from_uuid(Uuid::new_v4()),
+            movie_id: MovieId::from_uuid(Uuid::new_v4()),
+            user_id: UserId::from_uuid(Uuid::new_v4()),
+            rating: Rating::new(5).unwrap(),
+            watched_at: dt(),
+        };
+        assert_eq!(
+            event_to_subject("movies-diary.events", &event),
+            "movies-diary.events.review.updated"
+        );
+    }
+
+    #[test]
+    fn movie_discovered_subject() {
+        let event = DomainEvent::MovieDiscovered {
+            movie_id: MovieId::from_uuid(Uuid::new_v4()),
+            external_metadata_id: ExternalMetadataId::new("tt0000001".into()).unwrap(),
+        };
+        assert_eq!(
+            event_to_subject("movies-diary.events", &event),
+            "movies-diary.events.movie.discovered"
+        );
+    }
+
+    #[test]
+    fn consumer_subject_filter_appends_wildcard() {
+        assert_eq!(
+            consumer_subject_filter("movies-diary.events"),
+            "movies-diary.events.>"
+        );
+    }
+}