fix: mark forms updated with update_form/4 as touched by default

lib/ash_phoenix/form/form.ex

@@ -1370,8 +1370,18 @@ defmodule AshPhoenix.Form do
     end
   end
 
+  @update_form_opts [
+    mark_as_touched?: [
+      type: :boolean,
+      default: true,
+      doc: "Whether or not to mark the path to the updating form as touched"
+    ]
+  ]
+
   @spec update_form(t(), list(atom | integer) | String.t(), (t() -> t())) :: t()
-  def update_form(form, path, func) do
+  def update_form(form, path, func, opts \\ []) do
+    opts = Ash.OptionsHelpers.validate!(opts, @update_form_opts)
+
     path =
       case path do
         [] ->
@@ -1395,14 +1405,36 @@ defmodule AshPhoenix.Form do
             List.update_at(nested_forms, integer, &update_form(&1, rest, func))
           end)
 
-        %{form | forms: new_forms}
+        if opts[:mark_as_touched?] do
+          %{
+            form
+            | forms: new_forms,
+              touched_forms: MapSet.put(form.touched_forms, to_string(atom))
+          }
+        else
+          %{
+            form
+            | forms: new_forms
+          }
+        end
 
       [atom | rest] ->
         new_forms =
           form.forms
-          |> Map.update!(atom, &update_form(&1, rest, func))
+          |> Map.update!(atom, &update_form(&1, rest, func, opts))
 
-        %{form | forms: new_forms}
+        if opts[:mark_as_touched?] do
+          %{
+            form
+            | forms: new_forms,
+              touched_forms: MapSet.put(form.touched_forms, to_string(atom))
+          }
+        else
+          %{
+            form
+            | forms: new_forms
+          }
+        end
     end
   end
 

test/form_test.exs

@@ -51,6 +51,26 @@ defmodule AshPhoenix.FormTest do
                "Unhandled error in form submission for AshPhoenix.Test.Comment.create_with_unknown_error"
     end
 
+    test "update_form marks touched by default" do
+      form =
+        Post
+        |> Form.for_create(:create,
+          api: Api,
+          params: %{"text" => "bar"},
+          forms: [
+            comments: [
+              type: :list,
+              resource: Comment,
+              create_action: :create_with_unknown_error
+            ]
+          ]
+        )
+        |> Form.add_form([:comments], params: %{"text" => "foo"})
+        |> Form.update_form([:comments, 0], & &1)
+
+      assert MapSet.member?(form.touched_forms, "comments")
+    end
+
     test "errors are not set on the parent and single child form" do
       form =
         Comment