Support IN query param operator

src/PgQuery.hs

@@ -138,15 +138,22 @@ update t cols vals = B.Stmt
 
 wherePred :: Net.QueryItem -> PStmt
 wherePred (col, predicate) = B.Stmt
-  (" " <> cs (pgFmtIdent $ cs col) <> " " <> op <> " " <> cs (pgFmtLit value) <> "::unknown ")
+  (" " <> cs (pgFmtIdent $ cs col) <> " " <> op <> " " <> cs sqlValue)
   empty True
 
   where
     opCode:rest = T.split (=='.') $ cs $ fromMaybe "." predicate
-    unStarredVal = T.intercalate "." rest
+    value = T.intercalate "." rest
+
     star c = if c == '*' then '%' else c
-    value = if opCode == "like" || opCode == "ilike"
+    unknownLiteral = (<> "::unknown ") . pgFmtLit
-              then T.map star unStarredVal else unStarredVal
+
+    sqlValue = case opCode of
+            "like" -> unknownLiteral $ T.map star value
+            "ilike" -> unknownLiteral $ T.map star value
+            "in" -> "(" <> T.intercalate ", " (map unknownLiteral $ T.split (==',') value) <> ") "
+            _    -> unknownLiteral value
+
     op = case opCode of
          "eq"  -> "="
          "gt"  -> ">"
@@ -156,6 +163,7 @@ wherePred (col, predicate) = B.Stmt
          "neq" -> "<>"
          "like"-> "like"
          "ilike"-> "ilike"
+         "in"  -> "in"
          _     -> "="
 
 orderParse :: Net.Query -> [OrderTerm]

test/Feature/QuerySpec.hs

@@ -38,6 +38,14 @@ spec = beforeAll testSet . afterAll_ (clearTable "items") . around withApp $ do
         , matchHeaders = ["Content-Range" <:> "0-0/1"]
         }
 
+    it "matches items IN" $
+      get "/items?id=in.1,3,5"
+        `shouldRespondWith` ResponseMatcher {
+          matchBody    = Just [json| [{"id":1},{"id":3},{"id":5}] |]
+        , matchStatus  = 200
+        , matchHeaders = ["Content-Range" <:> "0-2/3"]
+        }
+
     it "matches with like" $ do
       get "/no_pk?a=like.*yx" `shouldRespondWith` [json|
         [{"a":"xyyx","b":"u"}]|]