add obs_controller integration tests

test/integration/obs_controller_test.rb

@@ -0,0 +1,23 @@
+require File.expand_path('../../test_helper', __FILE__)
+
+class OBSControllerTest < ActionDispatch::IntegrationTest
+  def test_backend_connection
+    get '/explore'
+
+    assert_includes body, 'Search packages...'
+    assert_equal 200, status
+  end
+
+  def test_backend_error_handling
+    mock = Minitest::Mock.new
+    def mock.get
+      raise Error
+    end
+
+    ApiConnect.stub :get, mock do
+      get '/explore'
+      assert_includes body, 'Connection to OBS is unavailable.'
+      assert_equal 200, status
+    end
+  end
+end