Add coverage for misc serializers (#32781)

spec/serializers/activitypub/actor_serializer_spec.rb

@@ -0,0 +1,39 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+
+RSpec.describe ActivityPub::ActorSerializer do
+  subject { serialized_record_json(record, described_class) }
+
+  describe '#type' do
+    context 'with the instance actor' do
+      let(:record) { Account.find(Account::INSTANCE_ACTOR_ID) }
+
+      it { is_expected.to include('type' => 'Application') }
+    end
+
+    context 'with an application actor' do
+      let(:record) { Fabricate :account, actor_type: 'Application' }
+
+      it { is_expected.to include('type' => 'Service') }
+    end
+
+    context 'with a service actor' do
+      let(:record) { Fabricate :account, actor_type: 'Service' }
+
+      it { is_expected.to include('type' => 'Service') }
+    end
+
+    context 'with a Group actor' do
+      let(:record) { Fabricate :account, actor_type: 'Group' }
+
+      it { is_expected.to include('type' => 'Group') }
+    end
+
+    context 'with a Person actor' do
+      let(:record) { Fabricate :account, actor_type: 'Person' }
+
+      it { is_expected.to include('type' => 'Person') }
+    end
+  end
+end