chore: fix dalli tests to account for upstream changes to Dalli:DalliError handling (#1041)

* chore: fix tests to account for sock nil check

* chore: fix tests so that retry behavior is supported for different versions

Author: ericmustin

instrumentation/dalli/test/opentelemetry/instrumentation/dalli/instrumentation_test.rb

@@ -80,11 +80,16 @@
       dalli.set('foo', 'bar')
       exporter.reset
 
-      dalli.instance_variable_get(:@ring).servers.first.stub(:write, ->(_bytes) { raise Dalli::DalliError }) do
+      dalli.instance_variable_get(:@ring).servers.first.stub(:write, ->(_bytes) { raise Dalli::NetworkError }) do
         dalli.get_multi('foo', 'bar')
       end
 
-      _(exporter.finished_spans.size).must_equal 1
+      if supports_retry_on_network_errors?
+        _(exporter.finished_spans.size).must_equal 2
+      else
+        _(exporter.finished_spans.size).must_equal 1
+      end
+
       _(span.name).must_equal 'getkq'
       _(span.attributes['db.system']).must_equal 'memcached'
       _(span.attributes['db.statement']).must_equal 'getkq foo bar'
@@ -93,8 +98,8 @@
 
       span_event = span.events.first
       _(span_event.name).must_equal 'exception'
-      _(span_event.attributes['exception.type']).must_equal 'Dalli::DalliError'
-      _(span_event.attributes['exception.message']).must_equal 'Dalli::DalliError'
+      _(span_event.attributes['exception.type']).must_equal 'Dalli::NetworkError'
+      _(span_event.attributes['exception.message']).must_equal 'Dalli::NetworkError'
     end
 
     it 'omits db.statement' do
@@ -119,4 +124,10 @@
       _(span.attributes['db.statement']).must_equal 'set ?'
     end
   end
+
+  # Dalli 3.x has different behavior than 2.x versions and attempts to retry on network errors
+  # https://github.com/petergoldstein/dalli/pull/754
+  def supports_retry_on_network_errors?
+    Gem.loaded_specs['dalli'].version >= Gem::Version.new('3.0.0')
+  end
 end unless ENV['OMIT_SERVICES']