add tests and fix empty set handling

tatut · Sep 20, 2024 · 257081f · 257081f
1 parent 78ba5ad
commit 257081f
Show file tree

Hide file tree

Showing 2 changed files with 24 additions and 15 deletions.
diff --git a/src/specql/op.clj b/src/specql/op.clj
@@ -83,18 +83,20 @@
 (defrecord Overlapsop [values]
   Op
   (to-sql [_ v {transform ::xf/transform type :type enum? :enum? :as column-info}]
-    (let [values (if transform
-                   (map #(xf/to-sql transform %) values)
-                   values)
-          param (if enum?
-                  (str "?::" type)
-                  "?")]
-      [(str v " && ["
-            (if (empty? values)
-              "NULL"
-              (str/join "," (repeat (count values) param)))
-            "]")
-       (vec values)])))
+    (if (empty? values)
+      ["FALSE" []]  ; Ensure no results are returned for empty set.
+                                        ; PostgreSQL also considers .. && ARRAY[] to be false.
+                                        ; (In set theory the empty set is considered to
+      (let [values (if transform
+                     (map #(xf/to-sql transform %) values)
+                     values)
+            param (if enum?
+                    (str "?::" type)
+                    "?")]
+        [(str v " && ARRAY["
+              (str/join "," (repeat (count values) param))
+              "]")
+         (vec values)]))))
 
 (defn overlaps [values]
   (assert (clojure.core/and

diff --git a/test/specql/core_test.clj b/test/specql/core_test.clj
@@ -814,9 +814,16 @@
                   {:issue/status (op/in #{:issue.status/resolved})}))))
 
   (testing "Overlaps operator"
-    (is (= (list {:issue/title "I have some issues"})
-           (fetch db :issue/issue #{:issue/idhistory :issue/title}
-                  {:issue/idhistory (op/overlaps #{42})}))))
+    (is (= (list {:issue/idhistory [42, 23] :issue/title "I have some issues"})
+           (fetch db :issue/issue #{:issue/title :issue/idhistory}
+                  {:issue/idhistory (op/overlaps #{(int 42)})})))
+
+    (is (empty?
+         (fetch db :issue/issue #{:issue/title :issue/idhistory}
+                {:issue/idhistory (op/overlaps #{(int 43)})})))
+    (is (empty?
+         (fetch db :issue/issue #{:issue/title :issue/idhistory}
+                {:issue/idhistory (op/overlaps #{})}))))
 
   (testing "Upsert transformed"
     (let [issue (upsert! db :issue/issue