fix: support only predicate in params

lib/ash_phoenix/filter_form/filter_form.ex

@@ -87,18 +87,18 @@ defmodule AshPhoenix.FilterForm do
   At present, no validation actually occurs, but this will eventually be added.
   """
   def validate(form, params \\ %{}) do
+    params = sanitize_params(params)
+
     params =
       if is_predicate?(params) do
         %{
-          operator: :and,
-          components: %{"0" => params}
+          "operator" => "and",
+          "components" => %{"0" => params}
         }
       else
         params
       end
 
-    params = sanitize_params(params)
-
     %{
       form
       | params: params,

test/filter_form_test.exs

@@ -77,7 +77,11 @@ defmodule AshPhoenix.FilterFormTest do
   describe "to_filter/1" do
     test "An empty form returns the filter `true`" do
       form = FilterForm.new(Post)
-      assert Ash.Query.equivalent_to?(FilterForm.filter!(Post, form), true)
+
+      assert Ash.Query.equivalent_to?(
+               FilterForm.filter!(Post, form),
+               true
+             )
     end
 
     test "A form with a single predicate returns the corresponding filter" do