fix tests

lib/datadog/tracing/transport/serializable_trace.rb

@@ -73,7 +73,7 @@ def to_msgpack(packer = nil)
           end
 
           # convert span events to tags
-          span.set_tag('events', span.events.map(&:to_hash).to_json) if span.events.count
+          span.set_tag('events', span.events.map(&:to_hash).to_json) if span.events.count > 0
 
           # DEV: We use strings as keys here, instead of symbols, as
           # DEV: MessagePack will ultimately convert them to strings.

spec/datadog/tracing/span_spec.rb

@@ -245,6 +245,7 @@
         meta: {},
         metrics: {},
         span_links: [],
+        span_events: [],
         error: 0
       )
     end

spec/datadog/tracing/transport/serializable_trace_spec.rb

@@ -128,6 +128,52 @@
         )
       end
     end
+
+    context 'when given span events' do
+      subject(:unpacked_trace) { MessagePack.unpack(to_msgpack) }
+
+      let(:spans) do
+        Array.new(3) do |_i|
+          Datadog::Tracing::Span.new(
+            'dummy',
+            events: [
+              Datadog::Tracing::SpanEvent.new(
+                'event1',
+                time_unix_nano: 1862312345678901234,
+              ),
+              Datadog::Tracing::SpanEvent.new(
+                'event2',
+                time_unix_nano: 23243675464378901235,
+                attributes: { 'event.attr' => 'some_val1', 'event.attr2' => 'some_val2' }
+              )
+            ],
+          )
+        end
+      end
+
+      it 'serializes span events' do
+        expect(
+          unpacked_trace.map do |s|
+            s['meta']['events']
+          end
+        ).to all(
+          eq(
+            [
+              {
+                'name' => 1,
+                'time_unix_nano' => 0xffffffffffffffff,
+                'attributes' => { 'link.name' => 'test_link' }
+              },
+              {
+                'name' => 1,
+                'time_unix_nano' => 0xffffffffffffffff,
+                'attributes' => { 'link.name' => 'test_link' }
+              },
+            ]
+          )
+        )
+      end
+    end
   end
 
   describe '#to_json' do