Added empty table description.

src/database/mod.rs

@@ -18,6 +18,10 @@ impl Table {
     async fn name(&self) -> String {
         self.name.to_string()
     }
+
+    async fn describe(&self) -> Vec<u64> {
+        Vec::new()
+    }
 }
 
 struct Query;
@@ -135,6 +139,16 @@ mod queries {
         let expected = r#"{"data":{"tables":[{"name":"barney"},{"name":"fred"}]}}"#;
         support::compare(&db, &output, &expected);
     }
+
+    #[async_std::test]
+    async fn empty_table_description() {
+        let db = Database::new();
+        let output = db
+            .execute(r#"mutation {createTable(name: "pebbles"){name describe}}"#)
+            .await;
+        let expected = r#"{"data":{"createTable":{"name":"pebbles","describe":[]}}}"#;
+        support::compare(&db, &output, &expected);
+    }
 }
 
 #[cfg(test)]