Fixed: SyncWriter raising NoMethodError for #runtime_metrics.

lib/ddtrace/sync_writer.rb

@@ -1,13 +1,22 @@
+require 'ddtrace/runtime/metrics'
+
 module Datadog
   # SyncWriter flushes both services and traces synchronously
   class SyncWriter
-    attr_reader :transport
+    attr_reader \
+      :runtime_metrics,
+      :transport
 
     def initialize(options = {})
       @transport = options.fetch(:transport) do
         transport_options = options.fetch(:transport_options, {})
         HTTPTransport.new(transport_options)
       end
+
+      # Runtime metrics
+      @runtime_metrics = options.fetch(:runtime_metrics) do
+        Runtime::Metrics.new
+      end
     end
 
     def write(trace, services = nil)

spec/ddtrace/sync_writer_spec.rb

@@ -0,0 +1,13 @@
+require 'spec_helper'
+
+require 'ddtrace'
+require 'ddtrace/sync_writer'
+
+RSpec.describe Datadog::SyncWriter do
+  subject(:sync_writer) { described_class.new }
+
+  describe '#runtime_metrics' do
+    subject(:runtime_metrics) { sync_writer.runtime_metrics }
+    it { is_expected.to be_a_kind_of(Datadog::Runtime::Metrics) }
+  end
+end