1 files changed, 26 insertions, 0 deletions
diff --git a/spec/serializers/diff_file_base_entity_spec.rb b/spec/serializers/diff_file_base_entity_spec.rb
new file mode 100644
index 00000000000..68c5c665ed6
--- /dev/null
+++ b/spec/serializers/diff_file_base_entity_spec.rb
@@ -0,0 +1,26 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe DiffFileBaseEntity do
+  let(:project) { create(:project, :repository) }
+  let(:repository) { project.repository }
+
+  context 'diff for a changed submodule' do
+    let(:commit_sha_with_changed_submodule) do
+      "cfe32cf61b73a0d5e9f13e774abde7ff789b1660"
+    end
+    let(:commit) { project.commit(commit_sha_with_changed_submodule) }
+    let(:diff_file) { commit.diffs.diff_files.to_a.last }
+    let(:options) { { request: {}, submodule_links: Gitlab::SubmoduleLinks.new(repository) } }
+    let(:entity) { described_class.new(diff_file, options).as_json }
+
+    it do
+      expect(entity[:submodule]).to eq(true)
+      expect(entity[:submodule_link]).to eq("https://github.com/randx/six")
+      expect(entity[:submodule_tree_url]).to eq(
+        "https://github.com/randx/six/tree/409f37c4f05865e4fb208c771485f211a22c4c2d"
+      )
+    end
+  end
+end