test(relay): cover exact #buzz-channel matching against tag decoys

Containment-only matching let a newer event carrying ["x","buzz-channel",<id>] take a limit-1 project or repository lookup. Also reattach the e-tag planner comment and describe the positional check in the tag field docs.

Co-authored-by: Will Pfleger <pfleger.will@gmail.com>
Signed-off-by: Will Pfleger <pfleger.will@gmail.com>

crates/buzz-db/src/store/event.rs

@@ -89,11 +89,13 @@ pub struct EventQuery {
     /// column is NULL (not NIP-33), so this lets identity lookups match before
     /// SQL `LIMIT`. Rows of other kinds are left to the caller's post-filter.
     pub d_tag_values: Option<Vec<String>>,
-    /// Restrict results to events with an exact custom tag pair.
-    /// Uses JSONB containment against `tags` before SQL `LIMIT`.
+    /// Restrict results to events with an exact custom tag pair: a tag whose
+    /// first element is the name and second the value, checked positionally
+    /// (JSONB containment is only the index prefilter) before SQL `LIMIT`.
     pub custom_tag: Option<(String, String)>,
-    /// Restrict results to events with a `t` tag of this value. Uses JSONB
-    /// containment against `tags` before SQL `LIMIT`, so a per-subject read
+    /// Restrict results to events with a `t` tag of this value, checked
+    /// positionally (JSONB containment is only the index prefilter) before
+    /// SQL `LIMIT`, so a per-subject read
     /// (e.g. a kind:44300 team's current version) is not starved by newer
     /// events with other `t` values.
     pub t_tag: Option<String>,
@@ -860,9 +862,6 @@ async fn fetch_with_e_tag_deadline(
     Ok(rows)
 }
 
-/// e-tag pushdown as one array-bound containment test instead of an N-way
-/// `OR` chain, so planner cost does not scale with the number of referenced
-/// ids (the thread aux hop sends one id per reply).
 /// Match a tag whose first element is `name` and second is `value` (NIP-01).
 ///
 /// JSONB containment alone ignores element position and multiplicity:
@@ -887,6 +886,9 @@ fn push_exact_tag_filter(
     .push(")");
 }
 
+/// e-tag pushdown as one array-bound containment test instead of an N-way
+/// `OR` chain, so planner cost does not scale with the number of referenced
+/// ids (the thread aux hop sends one id per reply).
 fn push_e_tag_filter(qb: &mut QueryBuilder<sqlx::Postgres>, col_prefix: &str, e_tags: &[String]) {
     let containments: Vec<serde_json::Value> = e_tags
         .iter()

crates/buzz-relay/src/api/artifact_postgres_tests.rs

@@ -144,25 +144,34 @@ impl Fixture {
 #[ignore = "requires Postgres"]
 async fn project_filter_survives_artifact_query_hook() {
     let f = Fixture::new().await;
-    let project = EventBuilder::new(Kind::Custom(30621), "")
-        .tags([
-            Tag::parse(["d", "review-project"]).unwrap(),
-            Tag::parse(["buzz-channel", &f.home.to_string()]).unwrap(),
-        ])
-        .sign_with_keys(&f.owner)
-        .unwrap();
-    f.state
-        .db
-        .insert_event(f.community, &project, None)
-        .await
-        .unwrap();
-    let filter = json!([{"kinds":[30621],"#buzz-channel":[f.home]}]);
-    let (status, body) = f.request("/query", filter.clone()).await;
-    assert!(status.is_success(), "{status}: {body}");
-    assert_eq!(body.as_array().unwrap().len(), 1);
-    assert_eq!(body[0]["id"], project.id.to_hex());
-    let (status, body) = f.request("/count", filter).await;
-    assert!(status.is_success(), "{status}: {body}");
+    let home = f.home.to_string();
+    // 30621 projects and 30617 repositories bind a channel via `buzz-channel`.
+    for kind in [30621u16, 30617] {
+        let event = |tag: &[&str], at: u64| {
+            EventBuilder::new(Kind::Custom(kind), "")
+                .tags([
+                    Tag::parse(["d", &Uuid::new_v4().to_string()]).unwrap(),
+                    Tag::parse(tag.iter().copied()).unwrap(),
+                ])
+                .custom_created_at(nostr::Timestamp::from(at))
+                .sign_with_keys(&f.owner)
+                .unwrap()
+        };
+        let now = nostr::Timestamp::now().as_secs();
+        let bound = event(&["buzz-channel", &home], now - 10);
+        // Newer, unbound: `buzz-channel` and the wanted id sit in an unrelated tag.
+        let decoy = event(&["x", "buzz-channel", &home], now);
+        for e in [&bound, &decoy] {
+            f.state.db.insert_event(f.community, e, None).await.unwrap();
+        }
+        let filter = json!([{"kinds":[kind],"#buzz-channel":[f.home],"limit":1}]);
+        let (status, body) = f.request("/query", filter.clone()).await;
+        assert!(status.is_success(), "{kind} {status}: {body}");
+        assert_eq!(body.as_array().unwrap().len(), 1, "{kind}: {body}");
+        assert_eq!(body[0]["id"], bound.id.to_hex(), "{kind}: {body}");
+        let (status, body) = f.request("/count", filter).await;
+        assert!(status.is_success(), "{kind} {status}: {body}");
+    }
 }
 
 #[tokio::test]

crates/buzz-search/tests/postgres_fts_integration.rs

@@ -1323,7 +1323,7 @@ async fn author_only_kinds_are_unsearchable() {
         assert!(
             !kinds.contains(&(kind as i32)),
             "AUTHOR_ONLY kind:{kind} MUST NOT be searchable — \
-             schema skip-set is missing this kind. AUTHOR_ONLY_KINDS={AUTHOR_ONLY_KINDS:?}, \
+             schema exclusion or query fence is missing this kind. AUTHOR_ONLY_KINDS={AUTHOR_ONLY_KINDS:?}, \
              hits={kinds:?}",
         );
     }