fix: Prevent OpenCensus integration from getting out of sync on uploa…

…d commands

lib/google/apis/core/http_command.rb

@@ -385,14 +385,16 @@ def opencensus_end_span
           return unless @opencensus_span
           return unless OpenCensus::Trace.span_context
 
-          if @http_res.body.respond_to? :bytesize
-            @opencensus_span.put_message_event \
-              OpenCensus::Trace::SpanBuilder::RECEIVED, 1, @http_res.body.bytesize
-          end
-          status = @http_res.status.to_i
-          if status > 0
-            @opencensus_span.set_status map_http_status status
-            @opencensus_span.put_attribute "http.status_code", status
+          if @http_res
+            if @http_res.body.respond_to? :bytesize
+              @opencensus_span.put_message_event \
+                OpenCensus::Trace::SpanBuilder::RECEIVED, 1, @http_res.body.bytesize
+            end
+            status = @http_res.status.to_i
+            if status > 0
+              @opencensus_span.set_status map_http_status status
+              @opencensus_span.put_attribute "http.status_code", status
+            end
           end
 
           OpenCensus::Trace.end_span @opencensus_span

spec/google/apis/core/upload_spec.rb

@@ -177,6 +177,16 @@
       expect(a_request(:post, 'https://www.googleapis.com/zoo/animals')
         .with(body: 'Hello world')).to have_been_made
     end
+
+    it 'should generate a proper opencensus span' do
+      OpenCensus::Trace.start_request_trace do |span_context|
+        command.execute(client)
+        spans = span_context.build_contained_spans
+        expect(spans.size).to eql 1
+        span = spans.first
+        expect(span.name.value).to eql '/zoo/animals'
+      end
+    end
   end
 
   context 'with retriable error on start' do