Add SearchResults.uniqueMatchesBy

Author: hojberg

src/Lib/SearchResults.elm

@@ -23,6 +23,7 @@ module Lib.SearchResults exposing
     , prev
     , toList
     , toMaybe
+    , uniqueMatchesBy
     )
 
 import List.Extra as ListE
@@ -111,6 +112,24 @@ mapToList f results =
             mapMatchesToList f matches
 
 
+uniqueMatchesBy : (a -> b) -> SearchResults a -> SearchResults a
+uniqueMatchesBy f results =
+    case results of
+        Empty ->
+            Empty
+
+        SearchResults (Matches matches) ->
+            SearchResults
+                (Matches
+                    (matches
+                        |> Zipper.toList
+                        |> ListE.uniqueBy f
+                        |> Zipper.fromList
+                        |> Maybe.withDefault matches
+                    )
+                )
+
+
 filterMatches : (a -> Bool) -> SearchResults a -> SearchResults a
 filterMatches f results =
     case results of

tests/Lib/SearchResultsTests.elm

@@ -154,6 +154,29 @@ getAt =
 
 
 
+-- MAP
+
+
+uniqueMatchesBy : Test
+uniqueMatchesBy =
+    describe "SearchResults.uniqueMatchesBy"
+        [ test "Removes duplicates based on the function" <|
+            \_ ->
+                let
+                    result =
+                        SearchResults.from [ "a", "b" ] "b" [ "c", "a", "c" ]
+                            |> SearchResults.uniqueMatchesBy
+                                (\x -> x)
+                            |> SearchResults.toList
+
+                    expected =
+                        [ "a", "b", "c" ]
+                in
+                Expect.equal expected result
+        ]
+
+
+
 -- MAP