Do not filter out parameters with the same name in pagination links

CHANGELOG.md

@@ -2,6 +2,11 @@
 
 None
 
+## [v1.1.2.2](https://github.com/pbrisbin/yesod-paginator/compare/v1.1.2.1...v1.1.2.2)
+
+- Fix (issue with filtering out query
+  parameters)[https://github.com/pbrisbin/yesod-paginator/issues/40]
+
 ## [v1.1.2.1](https://github.com/pbrisbin/yesod-paginator/compare/v1.1.2.0...v1.1.2.1)
 
 - Support GHCs 9.0 and 9.2

package.yaml

@@ -1,5 +1,5 @@
 name: yesod-paginator
-version: 1.1.2.1
+version: 1.1.2.2
 synopsis: A pagination approach for yesod
 description: Paginate a list showing a per-item widget and links to other pages
 category: Web, Yesod

src/Yesod/Paginator/Widgets.hs

@@ -7,6 +7,9 @@ module Yesod.Paginator.Widgets
     , simpleWith
     , ellipsed
     , ellipsedWith
+
+    -- * Exported for testing
+    , filterParams
     ) where
 
 import Yesod.Paginator.Prelude
@@ -178,12 +181,14 @@ getUpdateGetParams
 getUpdateGetParams pageParamName = do
     params <- handlerToWidget $ reqGetParams <$> getRequest
     pure
-        $ \number ->
-              nubOn fst
-                  $ [(unPageParamName pageParamName, tshow number)]
-                  <> params
+        $ \number -> filterParams pageParamName number params
 
 renderGetParams :: [(Text, Text)] -> Text
 renderGetParams [] = ""
 renderGetParams ps = "?" <> T.intercalate "&" (map renderGetParam ps)
     where renderGetParam (k, v) = encodeText k <> "=" <> encodeText v
+
+filterParams :: Show a => PageParamName -> a -> [(Text, Text)] -> [(Text, Text)]
+filterParams pageParamName number params =
+  let name = unPageParamName pageParamName
+  in [(name, tshow number)] <> filter ((/=) name . fst) params

test/SpecHelper.hs

@@ -14,6 +14,7 @@ import Test.Hspec as X
 import Yesod.Core
 import Yesod.Paginator as X
 import Yesod.Paginator.Prelude as X
+import Yesod.Paginator.Widgets as X
 import Yesod.Test as X
 
 data App = App

test/Yesod/Paginator/WidgetsSpec.hs

@@ -1,8 +1,7 @@
 {-# LANGUAGE OverloadedStrings #-}
 module Yesod.Paginator.WidgetsSpec
     ( spec
-    )
-where
+    ) where
 
 import SpecHelper
 
@@ -189,3 +188,21 @@ spec = withApp $ do
             , "<li class=\"next disabled\"><a>»</a></li>"
             , "</ul>"
             ]
+
+    describe "filterParams" $ it "works" $ do
+        let pageParamName = PageParamName "p"
+            pageNumber :: Int
+            pageNumber = 3
+            params :: [(Text, Text)]
+            params =
+                [ ("p", "2")
+                , ("p", "3")
+                , ("foo", "bar")
+                , ("ids[]", "1")
+                , ("ids[]", "2")
+                ]
+
+        assertEq
+            "filters page params not equal to the page number but keeps query params with the same name"
+            (filterParams pageParamName pageNumber params)
+            [("p", "3"), ("foo", "bar"), ("ids[]", "1"), ("ids[]", "2")]

yesod-paginator.cabal

@@ -1,11 +1,11 @@
 cabal-version: 1.12
 
--- This file has been generated from package.yaml by hpack version 0.34.4.
+-- This file has been generated from package.yaml by hpack version 0.34.5.
 --
 -- see: https://github.com/sol/hpack
 
 name:           yesod-paginator
-version:        1.1.2.1
+version:        1.1.2.2
 synopsis:       A pagination approach for yesod
 description:    Paginate a list showing a per-item widget and links to other pages
 category:       Web, Yesod