refactor: the default tracer is nameless

api/lib/opentelemetry.rb

@@ -37,8 +37,8 @@ def tracer_provider
 
   # @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)
+  #  arguments, it returns an unnamed default tracer.
+  def tracer(name = nil, version = nil)
     tracer_provider.tracer(name, version)
   end
 

api/test/opentelemetry_test.rb

@@ -33,32 +33,41 @@
   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 'delegates to tracer provider with default name' do
-      mock_provider.expect(:tracer, Object.new, ['default', nil])
-      _ = OpenTelemetry.tracer
-      mock_provider.verify
+    describe 'default tracer' do
+      it 'returns the same instance when accessed multiple times' do
+        _(OpenTelemetry.tracer).must_equal(OpenTelemetry.tracer)
+      end
     end
 
-    it 'delegates to tracer provider with provided name' do
-      mock_provider.expect(:tracer, Object.new, ['foo', nil])
-      _ = OpenTelemetry.tracer('foo')
-      mock_provider.verify
-    end
+    describe 'delegation' do
+      before do
+        OpenTelemetry.tracer_provider = mock_provider
+      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
+      it 'delegates to tracer provider' do
+        mock_provider.expect(:tracer, Object.new, [nil, nil])
+        _ = OpenTelemetry.tracer
+        mock_provider.verify
+      end
+
+      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
+
   end
 
   describe '.logger' do