Support updating while retaining ids

mathieuprog · May 25, 2024 · 9bc13e2 · 9bc13e2
1 parent 512d6bf
commit 9bc13e2
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Showing 2 changed files with 40 additions and 2 deletions.
diff --git a/lib/polymorphic_embed.ex b/lib/polymorphic_embed.ex
@@ -262,6 +262,8 @@ defmodule PolymorphicEmbed do
       type_field: type_field
     } = field_options
 
+    list_data_for_field = Map.fetch!(changeset.data, field)
+
     embeds =
       Enum.map(list_params, fn params ->
         case do_get_polymorphic_module_from_map(params, type_field, types_metadata) do
@@ -275,8 +277,18 @@ defmodule PolymorphicEmbed do
             :ignore
 
           module ->
-            embed_changeset = changeset_fun.(struct(module), params)
-            embed_changeset = %{embed_changeset | action: :insert}
+            data_for_field =
+              Enum.find(list_data_for_field, fn datum ->
+                datum.id != nil and datum.id == params[:id] and datum.__struct__ == module
+              end)
+
+            embed_changeset =
+              if data_for_field do
+                %{changeset_fun.(data_for_field, params) | action: :update}
+              else
+                %{changeset_fun.(struct(module), params) | action: :insert}
+              end
+
             maybe_apply_changes(embed_changeset)
         end
       end)

diff --git a/test/polymorphic_embed_test.exs b/test/polymorphic_embed_test.exs
@@ -1260,6 +1260,32 @@ defmodule PolymorphicEmbedTest do
 
       assert Enum.at(reminder.contexts, 0).id != Enum.at(updated_reminder.contexts, 0).id
       assert Enum.at(reminder.contexts, 1).id != Enum.at(updated_reminder.contexts, 1).id
+
+      # Assert that we have same ids when the provided context element has an id
+      attrs = %{
+        contexts: [
+          %{
+            __type__: "device",
+            id: Enum.at(reminder.contexts, 0).id,
+            ref: "12345",
+            type: "cellphone",
+            address: "address"
+          },
+          %{
+            __type__: "age",
+            age: "aquarius",
+            address: "address"
+          }
+        ]
+      }
+
+      updated_reminder =
+        reminder
+        |> reminder_module.changeset(attrs)
+        |> Repo.update!()
+
+      assert Enum.at(reminder.contexts, 0).id == Enum.at(updated_reminder.contexts, 0).id
+      assert Enum.at(reminder.contexts, 1).id != Enum.at(updated_reminder.contexts, 1).id
     end
   end