Adding unit test for the new "views.rb" file

test/statistic/views_test.rb

@@ -0,0 +1,23 @@
+# frozen_string_literal: true
+
+require 'minitest_helper'
+
+describe Sidekiq::Statistic::Views do
+  before do
+    @views = Sidekiq::Statistic::Views
+  end
+
+  describe '.require_assets' do
+    it 'returns content if file exists' do
+      content = @views.require_assets('styles/common.css').first
+
+      _(content).must_match(/=== COMMON ===/)
+    end
+
+    it 'raises an error if file does not exist' do
+      assert_raises Errno::ENOENT do 
+        @views.require_assets('styles/abc.css')
+      end
+    end
+  end
+end