Handle when changes in the changeset is nil

Author: JohnDoneth

lib/upload/multi.ex

@@ -118,7 +118,7 @@ defmodule Upload.Multi do
 
       record_changeset =
         record
-        |> Ecto.Changeset.cast(%{field => Map.get(changeset.params, to_string(field))}, [])
+        |> Ecto.Changeset.cast(%{field => Map.get(changeset.params || %{}, to_string(field))}, [])
         |> Upload.Changeset.cast_attachment(field,
           key_function: fn _ ->
             key_function.(record)

test/support/data_case.ex

@@ -9,6 +9,8 @@ defmodule Upload.DataCase do
 
   using do
     quote do
+      use Upload.Testing
+
       import Upload.DataCase
       import Mock
     end
@@ -25,10 +27,6 @@ defmodule Upload.DataCase do
     Application.put_env(:upload, Upload.Storage, adapter: adapter, base_url: "http://example.com")
   end
 
-  def list_uploaded_keys do
-    Enum.to_list(Upload.Storage.list!())
-  end
-
   def errors_on(changeset) do
     Ecto.Changeset.traverse_errors(changeset, fn {message, opts} ->
       Enum.reduce(opts, message, fn {key, value}, acc ->

test/upload/multi_test.exs

@@ -1,6 +1,5 @@
 defmodule Upload.MultiTest do
   use Upload.DataCase
-  use Upload.Testing
 
   alias Upload.Storage
   alias Upload.Test.Person
@@ -30,6 +29,18 @@ defmodule Upload.MultiTest do
 
       assert errors_on(changeset)[:avatar] == ["is not a supported file type"]
     end
+
+    test "works when provided a changeset with nil changes" do
+      changeset = %{Person.changeset(%Person{}) | params: nil}
+
+      {:ok, _} =
+        Ecto.Multi.new()
+        |> Ecto.Multi.insert(:insert_person, changeset)
+        |> Upload.Multi.handle_changes(:upload_avatar, :insert_person, changeset, :avatar,
+          key_function: &key_function/1
+        )
+        |> Repo.transaction()
+    end
   end
 
   describe "create_variant" do