From f4bf715b74359dd2b93b3e553d61f92cb0f5f0f8 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Aziz=20K=C3=B6ksal?= <aziz.koeksal@gmail.com>
Date: Tue, 1 Oct 2024 15:29:47 +0200
Subject: [PATCH 1/2] `apply_changes/1`: convert nested schemaless validations

---
 lib/ecto/changeset.ex        |  3 +++
 test/ecto/changeset_test.exs | 17 +++++++++++++++++
 2 files changed, 20 insertions(+)

diff --git a/lib/ecto/changeset.ex b/lib/ecto/changeset.ex
index cd0daeffe9..8dd37b1a5f 100644
--- a/lib/ecto/changeset.ex
+++ b/lib/ecto/changeset.ex
@@ -2208,6 +2208,9 @@ defmodule Ecto.Changeset do
         {:ok, {tag, relation}} when tag in @relations ->
           apply_relation_changes(acc, key, relation, value)
 
+        {:ok, :map} when is_struct(value, Changeset) ->
+          Map.put(acc, key, apply_changes(value))
+
         {:ok, _} ->
           Map.put(acc, key, value)
 
diff --git a/test/ecto/changeset_test.exs b/test/ecto/changeset_test.exs
index 69e4400ee7..41e50c2d86 100644
--- a/test/ecto/changeset_test.exs
+++ b/test/ecto/changeset_test.exs
@@ -1073,6 +1073,23 @@ defmodule Ecto.ChangesetTest do
     assert changed_post.category == nil
   end
 
+  test "apply_changes/1 with nested schemaless validation" do
+    params = %{"seo_metadata" => %{"keywords" => ["foo", "bar"], "slug" => "my-post-1"}}
+
+    changeset =
+      %Post{}
+      |> changeset(params)
+      |> update_change(:seo_metadata, fn seo_metadata ->
+        {%{}, %{keywords: {:array, :string}, slug: :string}}
+        |> cast(seo_metadata || %{}, [:keywords, :slug])
+        |> validate_required([:keywords, :slug])
+      end)
+
+    changed_post = apply_changes(changeset)
+
+    assert changed_post.seo_metadata == %{keywords: ["foo", "bar"], slug: "my-post-1"}
+  end
+
   describe "apply_action/2" do
     test "valid changeset" do
       post = %Post{}

From 1ea1005d4d42ea673615af790dbfd85983dd968c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Aziz=20K=C3=B6ksal?= <aziz.koeksal@gmail.com>
Date: Wed, 2 Oct 2024 21:11:05 +0200
Subject: [PATCH 2/2] Added comment to `apply_changes/1` doc

---
 lib/ecto/changeset.ex | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/lib/ecto/changeset.ex b/lib/ecto/changeset.ex
index 8dd37b1a5f..a5051b0838 100644
--- a/lib/ecto/changeset.ex
+++ b/lib/ecto/changeset.ex
@@ -2190,6 +2190,9 @@ defmodule Ecto.Changeset do
   regardless if the changeset is valid or not. See `apply_action/2`
   for a similar function that ensures the changeset is valid.
 
+  If a field of type `:map` contains a schemaless changeset,
+  its changes too will be applied and returned as a map with atom keys.
+
   ## Examples
 
       iex> changeset = change(%Post{author: "bar"}, %{title: "foo"})