repro(filter): failed to filter array

lib/ash_json_api/test/test.ex

@@ -362,13 +362,16 @@ defmodule AshJsonApi.Test do
                "data" => results
              } = conn.resp_body
 
-      assert Enum.all?(results, fn
-               %{"type" => ^expected_type, "id" => maybe_known_id} ->
-                 Enum.member?(expected_ids, maybe_known_id)
-
-               _ ->
-                 false
-             end)
+      # Extract actual IDs from results
+      actual_ids =
+        Enum.map(results, fn
+          %{"type" => ^expected_type, "id" => id} -> id
+          other -> flunk("Unexpected result: #{inspect(other)}")
+        end)
+
+      # Check that we have exactly the expected IDs (order doesn't matter)
+      assert Enum.sort(actual_ids) == Enum.sort(expected_ids),
+             "Expected IDs #{inspect(expected_ids)}, but got #{inspect(actual_ids)}"
 
       conn
     end

test/spec_compliance/fetching_data/filtering_test.exs

@@ -4,6 +4,19 @@ defmodule AshJsonApiTest.FetchingData.Filtering do
 
   # credo:disable-for-this-file Credo.Check.Readability.MaxLineLength
 
+  defmodule Narrative do
+    use Ash.Type.Enum,
+      values: [
+        :novel,
+        :legend,
+        :myth,
+        :fable,
+        :tale,
+        :action,
+        :plot
+      ]
+  end
+
   defmodule Author do
     use Ash.Resource,
       domain: AshJsonApiTest.FetchingData.Filtering.Domain,
@@ -72,13 +85,18 @@ defmodule AshJsonApiTest.FetchingData.Filtering do
       defaults([:read, :update, :destroy])
 
       create :create do
-        accept([:name, :author_id])
+        accept([:name, :author_id, :narratives])
       end
     end
 
     attributes do
       uuid_primary_key(:id)
       attribute(:name, :string, public?: true)
+
+      attribute(:narratives, {:array, Narrative},
+        default: [],
+        public?: true
+      )
     end
 
     relationships do
@@ -162,6 +180,121 @@ defmodule AshJsonApiTest.FetchingData.Filtering do
         |> assert_invalid_resource_objects("post", [post.id])
     end
 
+    test "equals array filter" do
+      post =
+        Post
+        |> Ash.Changeset.for_create(:create, %{name: "foo", narratives: [:novel, :legend]})
+        |> Ash.create!()
+
+      post2 =
+        Post
+        |> Ash.Changeset.for_create(:create, %{name: "bar", narratives: [:legend]})
+        |> Ash.create!()
+
+      _conn =
+        Domain
+        |> get("/posts?filter[narratives][]=novel&filter[narratives][]=legend",
+          status: 200
+        )
+        |> assert_valid_resource_objects("post", [post.id])
+
+      # order of values matters
+      _conn =
+        Domain
+        |> get("/posts?filter[narratives][]=legend&filter[narratives][]=novel",
+          status: 200
+        )
+        |> assert_valid_resource_objects("post", [])
+
+      _conn =
+        Domain
+        |> get("/posts?filter[narratives][]=legend",
+          status: 200
+        )
+        |> assert_valid_resource_objects("post", [post2.id])
+
+      # it's not inclusion check
+      _conn =
+        Domain
+        |> get("/posts?filter[narratives][]=novel",
+          status: 200
+        )
+        |> assert_valid_resource_objects("post", [])
+    end
+
+    test "in/not_in array filter" do
+      post =
+        Post
+        |> Ash.Changeset.for_create(:create, %{name: "foo", narratives: [:novel, :legend]})
+        |> Ash.create!()
+
+      post2 =
+        Post
+        |> Ash.Changeset.for_create(:create, %{name: "bar", narratives: [:legend]})
+        |> Ash.create!()
+
+      # single value
+      # _conn =
+      #   Domain
+      #   |> get("posts/filter[narratives][in]=novel",
+      #     status: 200
+      #   )
+      #   |> assert_valid_resource_objects("post", [post.id, post2.id])
+
+      # comma-separated
+      # _conn =
+      #   Domain
+      #   |> get("/posts?filter[narratives][in]=novel,legend",
+      #     status: 200
+      #   )
+      #   |> assert_valid_resource_objects("post", [post.id, post2.id])
+
+      # deep object
+      # _conn =
+      #   Domain
+      #   |> get(
+      #     URI.encode(
+      #       "/posts?filter=[{name:\"narratives\", op: \"in\", val: [\"novel\",\"legend\"]}]"
+      #     ),
+      #     status: 200
+      #   )
+      #   |> assert_valid_resource_objects("post", [post.id, post2.id])
+
+      # PHP-style array
+      # _conn =
+      #   Domain
+      #   |> get("/posts?filter[narratives][in][]=novel&filter[narratives][in][]=legend",
+      #     status: 200
+      #   )
+      #   |> assert_valid_resource_objects("post", [post.id, post2.id])
+
+      # nested array
+      # _conn =
+      #   Domain
+      #   |> get("/posts?filter[narratives][in][][]=novel ",
+      #     status: 200
+      #   )
+      #   |> assert_valid_resource_objects("post", [post.id, post2.id])
+
+      # bracket notation
+      # _conn =
+      #   Domain
+      #   |> get("/posts?filter[narratives][in]=[novel,legend]", status: 200)
+      #   |> assert_valid_resource_objects("post", [post.id, post2.id])
+
+      _conn =
+        Domain
+        |> get("/posts?filter[narratives][in][0]=novel&filter[narratives][in][1]=legend",
+          status: 200
+        )
+        |> assert_valid_resource_objects("post", [post.id, post2.id])
+
+      # _conn =
+      #   Domain
+      #   |> get("/posts?filter[narratives][not_in]=novel,legend", status: 200)
+      #   |> assert_valid_resource_objects("post", [])
+    end
+
     test "is_nil filter" do
       post =
         Post