Improve TCK suite compliance (Cypher coverage)

Author: habedi

crates/issundb-py/tests/test_query.py

@@ -32,6 +32,17 @@ def test_query_aggregation(db):
     assert rows(result) == [[2]]
 
 
+def test_whole_entity_projection_is_a_display_literal(db):
+    """Pins the result contract: a whole node or relationship projects as an
+    openCypher display-literal string, not a property map. Changing this shape
+    is an API break for every consumer of query()."""
+    db.query("CREATE (:Person {name: 'Ada'})-[:KNOWS {since: 2020}]->(:Person {name: 'Bob'})")
+    nodes = json.loads(db.query("MATCH (n:Person {name: 'Ada'}) RETURN n"))
+    assert rows(nodes) == [["(:Person {name: 'Ada'})"]]
+    rels = json.loads(db.query("MATCH ()-[r:KNOWS]->() RETURN r"))
+    assert rows(rels) == [["[:KNOWS {since: 2020}]"]]
+
+
 def test_explain_returns_plan_text(db):
     plan = db.explain("MATCH (n:Person) RETURN n.name")
     assert isinstance(plan, str)

crates/issundb-rest/tests/routes.rs

@@ -345,6 +345,23 @@ async fn cypher_query_returns_columns_and_records() {
     assert_eq!(body["records"], json!([["Ada"], ["Grace"]]));
 }
 
+#[tokio::test]
+async fn whole_entity_projection_is_a_display_literal() {
+    // Pins the result contract: a whole node projects as an openCypher
+    // display-literal string, not a property map. Changing this shape is an
+    // API break for every consumer of /v1/query.
+    let (graph, _dir) = fresh_graph();
+    create_node(&graph, "Person", json!({ "name": "Ada" })).await;
+
+    let (status, body) = send(
+        &graph,
+        post("/v1/query", json!({ "query": "MATCH (n:Person) RETURN n" })),
+    )
+    .await;
+    assert_eq!(status, StatusCode::OK, "query body: {body}");
+    assert_eq!(body["records"], json!([["(:Person {name: 'Ada'})"]]));
+}
+
 #[tokio::test]
 async fn cypher_query_with_params() {
     let (graph, _dir) = fresh_graph();