From acc30b2b35347aa256530966c1625856745c2ff9 Mon Sep 17 00:00:00 2001
From: Matthew Wear <matthew.wear@gmail.com>
Date: Fri, 2 Oct 2020 16:47:34 -0700
Subject: [PATCH] feat: add OpenTelemetry.tracer convenience method

---
 api/lib/opentelemetry.rb               | 10 +++++-----
 api/test/opentelemetry_test.rb         | 27 ++++++++++++++++++++------
 sdk/test/integration/api_trace_test.rb |  6 ------
 3 files changed, 26 insertions(+), 17 deletions(-)

diff --git a/api/lib/opentelemetry.rb b/api/lib/opentelemetry.rb
index 2bf23fc339..f43b984198 100644
--- a/api/lib/opentelemetry.rb
+++ b/api/lib/opentelemetry.rb
@@ -35,11 +35,11 @@ def tracer_provider
     @tracer_provider ||= Trace::TracerProvider.new
   end
 
-  # @return [Trace::Tracer] returns a default tracer instance from the
-  #   registered tracer provider. If the tracer provider is operational, this
-  #   will be a named tracer with the name 'default'.
-  def default_tracer
-    tracer_provider.tracer('default')
+  # @return [Trace::Tracer] delegates to the registered tracer provider and
+  #  returns a tracer with the given name and version. If called without without
+  #  arguments, it returns a tracer named 'default'.
+  def tracer(name = 'default', version = nil)
+    tracer_provider.tracer(name, version)
   end
 
   # @return [Object, Metrics::MeterProvider] registered meter provider or a
diff --git a/api/test/opentelemetry_test.rb b/api/test/opentelemetry_test.rb
index 4dbb434178..602b8ac2ec 100644
--- a/api/test/opentelemetry_test.rb
+++ b/api/test/opentelemetry_test.rb
@@ -30,19 +30,34 @@
     end
   end
 
-  describe '.default_tracer' do
+  describe '.tracer' do
+    let(:mock_provider) { MiniTest::Mock.new }
+
+    before do
+      OpenTelemetry.tracer_provider = mock_provider
+    end
+
     after do
       # Ensure we don't leak custom tracer factories and tracers to other tests
       OpenTelemetry.tracer_provider = nil
     end
 
-    it 'returns instance of Trace::Tracer' do
-      default_tracer = OpenTelemetry.default_tracer
-      _(default_tracer).must_be_instance_of(OpenTelemetry::Trace::Tracer)
+    it 'delegates to tracer provider with default name' do
+      mock_provider.expect(:tracer, Object.new, ['default', nil])
+      _ = OpenTelemetry.tracer
+      mock_provider.verify
     end
 
-    it 'returns the same instance when accessed multiple times' do
-      _(OpenTelemetry.default_tracer).must_equal(OpenTelemetry.default_tracer)
+    it 'delegates to tracer provider with provided name' do
+      mock_provider.expect(:tracer, Object.new, ['foo', nil])
+      _ = OpenTelemetry.tracer('foo')
+      mock_provider.verify
+    end
+
+    it 'delegates to tracer provider with provided name and version' do
+      mock_provider.expect(:tracer, Object.new, ['foo', '0.4.0'])
+      _ = OpenTelemetry.tracer('foo', '0.4.0')
+      mock_provider.verify
     end
   end
 
diff --git a/sdk/test/integration/api_trace_test.rb b/sdk/test/integration/api_trace_test.rb
index c2e92016c5..c98d86878d 100644
--- a/sdk/test/integration/api_trace_test.rb
+++ b/sdk/test/integration/api_trace_test.rb
@@ -106,10 +106,4 @@
       _(@child_span_with_links.to_span_data.links.size).must_equal number_of_links
     end
   end
-
-  describe 'default tracer' do
-    it 'returns tracer named default' do
-      _(OpenTelemetry.default_tracer.name).must_equal('default')
-    end
-  end
 end