From 32b97ef07654a3237d815109247b9f9a14ed82eb Mon Sep 17 00:00:00 2001
From: Diogo Biazus <diogob@gmail.com>
Date: Mon, 17 Aug 2015 22:04:05 -0400
Subject: [PATCH] Adds not as a keyword that can optionally be prepended to any
 operator in a parameter value

---
 src/PostgREST/PgQuery.hs  |  9 ++++++---
 test/Feature/QuerySpec.hs | 13 ++++++++++++-
 2 files changed, 18 insertions(+), 4 deletions(-)

diff --git a/src/PostgREST/PgQuery.hs b/src/PostgREST/PgQuery.hs
index 741cf94a3..b82d78015 100644
--- a/src/PostgREST/PgQuery.hs
+++ b/src/PostgREST/PgQuery.hs
@@ -182,14 +182,17 @@ callProc qi params = do
 
 wherePred :: QualifiedIdentifier -> Net.QueryItem -> PStmt
 wherePred table (col, predicate) =
-  B.Stmt (" " <> pgFmtJsonbPath table (cs col) <> " " <> op <> " " <>
+  B.Stmt (notOp <> " " <> pgFmtJsonbPath table (cs col) <> " " <> op <> " " <>
       if opCode `elem` ["is","isnot"] then whiteList value
                                  else cs sqlValue)
       empty True
 
   where
-    opCode:rest = T.split (=='.') $ cs $ fromMaybe "." predicate
-    value = T.intercalate "." rest
+    headPredicate:rest = T.split (=='.') $ cs $ fromMaybe "." predicate
+    hasNot caseTrue caseFalse =  if headPredicate == "not" then caseTrue else caseFalse
+    opCode = hasNot (head rest) headPredicate
+    notOp  = hasNot headPredicate ""
+    value  = hasNot (T.intercalate "." $ tail rest) (T.intercalate "." rest)
     whiteList val = fromMaybe (cs (pgFmtLit val) <> "::unknown ")
                               (L.find ((==) . T.toLower $ val)
                                       ["null","true","false"])
diff --git a/test/Feature/QuerySpec.hs b/test/Feature/QuerySpec.hs
index 6256e195a..024ae307e 100644
--- a/test/Feature/QuerySpec.hs
+++ b/test/Feature/QuerySpec.hs
@@ -53,6 +53,14 @@ spec =
         , matchHeaders = ["Content-Range" <:> "0-2/3"]
         }
 
+    it "matches items NOT IN using not operator" $
+      get "/items?id=not.in.2,4,6,7,8,9,10,11,12,13,14,15"
+        `shouldRespondWith` ResponseMatcher {
+          matchBody    = Just [json| [{"id":1},{"id":3},{"id":5}] |]
+        , matchStatus  = 200
+        , matchHeaders = ["Content-Range" <:> "0-2/3"]
+        }
+
     it "matches nulls in varchar and numeric fields alike" $ do
       get "/no_pk?a=is.null" `shouldRespondWith`
         [json| [{"a": null, "b": null}] |]
@@ -166,12 +174,15 @@ spec =
         respHeaders `shouldSatisfy` matchHeader
           "Content-Location" "/simple_pk"
 
-  describe "jsonb" $
+  describe "jsonb" $ do
     it "can filter by properties inside json column" $ do
       get "/json?data->foo->>bar=eq.baz" `shouldRespondWith`
         [json| [{"data": {"foo": {"bar": "baz"}}}] |]
       get "/json?data->foo->>bar=eq.fake" `shouldRespondWith`
         [json| [] |]
+    it "can filter by properties inside json column using not" $
+      get "/json?data->foo->>bar=not.eq.baz" `shouldRespondWith`
+        [json| [] |]
 
   describe "remote procedure call" $ do
     context "a proc that returns a set" . before_ (clearTable "items" >> createItems 10) .