From 99c8a86fa97ba98f7750cedf19570e6f2b475943 Mon Sep 17 00:00:00 2001
From: Matthew Wear <matthew.wear@gmail.com>
Date: Thu, 17 Sep 2020 18:36:50 -0700
Subject: [PATCH 1/8] refactor: remove with_parent (span) option to start_span
 (and friends)

---
 api/benchmarks/tracer_bench.rb                      |  5 -----
 api/lib/opentelemetry/trace/tracer.rb               | 13 ++++---------
 api/test/opentelemetry/trace/tracer_test.rb         | 13 -------------
 .../opentelemetry/exporter/otlp/exporter_test.rb    | 11 +++++++----
 sdk/lib/opentelemetry/sdk/trace/tracer.rb           |  4 ++--
 sdk/test/integration/api_trace_test.rb              | 13 ++++++++-----
 sdk/test/opentelemetry/sdk/trace/tracer_test.rb     |  5 +++--
 7 files changed, 24 insertions(+), 40 deletions(-)

diff --git a/api/benchmarks/tracer_bench.rb b/api/benchmarks/tracer_bench.rb
index 5c152b2e0..f009ba796 100644
--- a/api/benchmarks/tracer_bench.rb
+++ b/api/benchmarks/tracer_bench.rb
@@ -31,11 +31,6 @@
     span.finish
   end
 
-  x.report 'start span with parent' do
-    span = tracer.start_span('test_span', with_parent: parent_span)
-    span.finish
-  end
-
   x.report 'start span with parent context' do
     span = tracer.start_span('test_span', with_parent_context: parent_span.context)
     span.finish
diff --git a/api/lib/opentelemetry/trace/tracer.rb b/api/lib/opentelemetry/trace/tracer.rb
index 117f95290..80e1c10fe 100644
--- a/api/lib/opentelemetry/trace/tracer.rb
+++ b/api/lib/opentelemetry/trace/tracer.rb
@@ -36,9 +36,9 @@ def current_span(context = nil)
       # span and reraised.
       # @yield [span, context] yields the newly created span and a context containing the
       #   span to the block.
-      def in_span(name, attributes: nil, links: nil, start_timestamp: nil, kind: nil, with_parent: nil, with_parent_context: nil)
+      def in_span(name, attributes: nil, links: nil, start_timestamp: nil, kind: nil, with_parent_context: nil)
         span = nil
-        span = start_span(name, attributes: attributes, links: links, start_timestamp: start_timestamp, kind: kind, with_parent: with_parent, with_parent_context: with_parent_context)
+        span = start_span(name, attributes: attributes, links: links, start_timestamp: start_timestamp, kind: kind, with_parent_context: with_parent_context)
         with_span(span) { |s, c| yield s, c }
       rescue Exception => e # rubocop:disable Lint/RescueException
         span&.record_exception(e)
@@ -69,14 +69,9 @@ def start_root_span(name, attributes: nil, links: nil, start_timestamp: nil, kin
       #
       # Parent context can be either passed explicitly, or inferred from currently activated span.
       #
-      # @param [optional Span] with_parent Explicitly managed parent Span, overrides
-      #   +with_parent_context+.
-      # @param [optional Context] with_parent_context Explicitly managed. Overridden by
-      #   +with_parent+.
-      #
       # @return [Span]
-      def start_span(name, with_parent: nil, with_parent_context: nil, attributes: nil, links: nil, start_timestamp: nil, kind: nil)
-        span_context = with_parent&.context || current_span(with_parent_context).context
+      def start_span(name, with_parent_context: nil, attributes: nil, links: nil, start_timestamp: nil, kind: nil)
+        span_context = current_span(with_parent_context).context
         if span_context.valid?
           Span.new(span_context: span_context)
         else
diff --git a/api/test/opentelemetry/trace/tracer_test.rb b/api/test/opentelemetry/trace/tracer_test.rb
index 7c11daff4..1d3991876 100644
--- a/api/test/opentelemetry/trace/tracer_test.rb
+++ b/api/test/opentelemetry/trace/tracer_test.rb
@@ -91,13 +91,6 @@ def start_span(*)
       mock_span.verify
     end
 
-    it 'yields a span with the same context as the parent' do
-      tracer.in_span('op', with_parent: parent) do |span|
-        _(span.context).must_be :valid?
-        _(span.context).must_equal(parent.context)
-      end
-    end
-
     it 'yields a span with the parent context' do
       tracer.in_span('op', with_parent_context: parent_context) do |span|
         _(span.context).must_be :valid?
@@ -162,12 +155,6 @@ def start_span(*)
       _(span.context).wont_equal(tracer.current_span.context)
     end
 
-    it 'returns a span with the same context as the parent' do
-      span = tracer.start_span('op', with_parent: parent)
-      _(span.context).must_be :valid?
-      _(span.context).must_equal(parent.context)
-    end
-
     it 'returns a span with a new context when passed an invalid context' do
       span = tracer.start_span('op', with_parent_context: invalid_parent_context)
       _(span.context).must_be :valid?
diff --git a/exporter/otlp/test/opentelemetry/exporter/otlp/exporter_test.rb b/exporter/otlp/test/opentelemetry/exporter/otlp/exporter_test.rb
index e3f645142..72d198752 100644
--- a/exporter/otlp/test/opentelemetry/exporter/otlp/exporter_test.rb
+++ b/exporter/otlp/test/opentelemetry/exporter/otlp/exporter_test.rb
@@ -154,17 +154,20 @@
 
       OpenTelemetry.tracer_provider.add_span_processor(processor)
       root = with_ids(trace_id, root_span_id) { tracer.start_root_span('root', kind: :internal, start_timestamp: start_timestamp).finish(end_timestamp: end_timestamp) }
-      span = with_ids(trace_id, child_span_id) { tracer.start_span('child', with_parent: root, kind: :producer, start_timestamp: start_timestamp + 1, links: [OpenTelemetry::Trace::Link.new(root.context, 'attr' => 4)]) }
+      root_ctx = tracer.with_span(root) { |_, ctx| ctx }
+      span = with_ids(trace_id, child_span_id) { tracer.start_span('child', with_parent_context: root_ctx, kind: :producer, start_timestamp: start_timestamp + 1, links: [OpenTelemetry::Trace::Link.new(root.context, 'attr' => 4)]) }
       span['b'] = true
       span['f'] = 1.1
       span['i'] = 2
       span['s'] = 'val'
       span['a'] = [3, 4]
       span.status = OpenTelemetry::Trace::Status.new(OpenTelemetry::Trace::Status::ERROR)
-      client = with_ids(trace_id, client_span_id) { tracer.start_span('client', with_parent: span, kind: :client, start_timestamp: start_timestamp + 2).finish(end_timestamp: end_timestamp) }
-      with_ids(trace_id, server_span_id) { other_tracer.start_span('server', with_parent: client, kind: :server, start_timestamp: start_timestamp + 3).finish(end_timestamp: end_timestamp) }
+      child_ctx = tracer.with_span(span) { |_, ctx| ctx }
+      client = with_ids(trace_id, client_span_id) { tracer.start_span('client', with_parent_context: child_ctx, kind: :client, start_timestamp: start_timestamp + 2).finish(end_timestamp: end_timestamp) }
+      client_ctx = tracer.with_span(client) { |_, ctx| ctx }
+      with_ids(trace_id, server_span_id) { other_tracer.start_span('server', with_parent_context: client_ctx, kind: :server, start_timestamp: start_timestamp + 3).finish(end_timestamp: end_timestamp) }
       span.add_event('event', attributes: { 'attr' => 42 }, timestamp: start_timestamp + 4)
-      with_ids(trace_id, consumer_span_id) { tracer.start_span('consumer', with_parent: span, kind: :consumer, start_timestamp: start_timestamp + 5).finish(end_timestamp: end_timestamp) }
+      with_ids(trace_id, consumer_span_id) { tracer.start_span('consumer', with_parent_context: child_ctx, kind: :consumer, start_timestamp: start_timestamp + 5).finish(end_timestamp: end_timestamp) }
       span.finish(end_timestamp: end_timestamp)
       OpenTelemetry.tracer_provider.shutdown
 
diff --git a/sdk/lib/opentelemetry/sdk/trace/tracer.rb b/sdk/lib/opentelemetry/sdk/trace/tracer.rb
index 923d567a7..a1340c447 100644
--- a/sdk/lib/opentelemetry/sdk/trace/tracer.rb
+++ b/sdk/lib/opentelemetry/sdk/trace/tracer.rb
@@ -33,10 +33,10 @@ def start_root_span(name, attributes: nil, links: nil, start_timestamp: nil, kin
           start_span(name, with_parent_context: Context.empty, attributes: attributes, links: links, start_timestamp: start_timestamp, kind: kind)
         end
 
-        def start_span(name, with_parent: nil, with_parent_context: nil, attributes: nil, links: nil, start_timestamp: nil, kind: nil)
+        def start_span(name, with_parent_context: nil, attributes: nil, links: nil, start_timestamp: nil, kind: nil)
           name ||= 'empty'
 
-          parent_span_context = with_parent&.context || current_span(with_parent_context).context
+          parent_span_context = current_span(with_parent_context).context
           parent_span_context = nil unless parent_span_context.valid?
           parent_span_id = parent_span_context&.span_id
           tracestate = parent_span_context&.tracestate
diff --git a/sdk/test/integration/api_trace_test.rb b/sdk/test/integration/api_trace_test.rb
index 5dc836ec0..c6c0b84cc 100644
--- a/sdk/test/integration/api_trace_test.rb
+++ b/sdk/test/integration/api_trace_test.rb
@@ -58,7 +58,9 @@
 
     before do
       @remote_span = tracer.start_span('remote', with_parent_context: context_with_remote_parent)
-      @child_of_remote = tracer.start_span('child1', with_parent: @remote_span)
+      tracer.with_span(@remote_span) do |_, ctx|
+        @child_of_remote = tracer.start_span('child1', with_parent_context: ctx)
+      end
     end
 
     it 'has a child' do
@@ -68,10 +70,11 @@
 
   describe 'tracing child-of-local spans' do
     before do
-      @local_parent_span = tracer.start_span('local')
-
-      tracer.in_span('child1', with_parent: @local_parent_span) do |span|
-        @child_of_local = span
+      tracer.in_span('local') do |parent|
+        @local_parent_span = parent
+        tracer.in_span('child1') do |child|
+          @child_of_local = child
+        end
       end
     end
 
diff --git a/sdk/test/opentelemetry/sdk/trace/tracer_test.rb b/sdk/test/opentelemetry/sdk/trace/tracer_test.rb
index a6cb95838..c18eca574 100644
--- a/sdk/test/opentelemetry/sdk/trace/tracer_test.rb
+++ b/sdk/test/opentelemetry/sdk/trace/tracer_test.rb
@@ -252,9 +252,10 @@
       _(span.attributes).must_equal('1' => 1, '2' => 2)
     end
 
-    it 'uses the context from parent span if supplied' do
+    it 'uses the context from parent if supplied' do
       parent = tracer.start_root_span('root')
-      span = tracer.start_span('child', with_parent: parent)
+      parent_ctx = tracer.with_span(parent) { |_, ctx| ctx }
+      span = tracer.start_span('child', with_parent_context: parent_ctx)
       _(span.parent_span_id).must_equal(parent.context.span_id)
       _(span.context.trace_id).must_equal(parent.context.trace_id)
     end

From 4e8668a241b38559be4a938bc362f8650b2816aa Mon Sep 17 00:00:00 2001
From: Matthew Wear <matthew.wear@gmail.com>
Date: Thu, 17 Sep 2020 18:40:52 -0700
Subject: [PATCH 2/8] refactor: rename with_parent_context to with_parent
 (context)

---
 api/benchmarks/tracer_bench.rb                |  2 +-
 api/lib/opentelemetry/trace/tracer.rb         |  9 +++---
 api/test/opentelemetry/trace/tracer_test.rb   |  6 ++--
 examples/http/server.rb                       |  2 +-
 .../exporter/otlp/exporter_test.rb            |  8 ++---
 .../rack/middlewares/tracer_middleware.rb     |  2 +-
 .../middlewares/server/tracer_middleware.rb   |  2 +-
 .../sinatra/middlewares/tracer_middleware.rb  |  2 +-
 sdk/lib/opentelemetry/sdk/trace/tracer.rb     |  6 ++--
 sdk/test/integration/api_trace_test.rb        |  4 +--
 .../global_tracer_configurations_test.rb      |  2 +-
 .../opentelemetry/sdk/trace/tracer_test.rb    | 32 +++++++++----------
 12 files changed, 39 insertions(+), 38 deletions(-)

diff --git a/api/benchmarks/tracer_bench.rb b/api/benchmarks/tracer_bench.rb
index f009ba796..686f1e8f3 100644
--- a/api/benchmarks/tracer_bench.rb
+++ b/api/benchmarks/tracer_bench.rb
@@ -32,7 +32,7 @@
   end
 
   x.report 'start span with parent context' do
-    span = tracer.start_span('test_span', with_parent_context: parent_span.context)
+    span = tracer.start_span('test_span', with_parent: parent_span.context)
     span.finish
   end
 
diff --git a/api/lib/opentelemetry/trace/tracer.rb b/api/lib/opentelemetry/trace/tracer.rb
index 80e1c10fe..f1fd19854 100644
--- a/api/lib/opentelemetry/trace/tracer.rb
+++ b/api/lib/opentelemetry/trace/tracer.rb
@@ -36,9 +36,9 @@ def current_span(context = nil)
       # span and reraised.
       # @yield [span, context] yields the newly created span and a context containing the
       #   span to the block.
-      def in_span(name, attributes: nil, links: nil, start_timestamp: nil, kind: nil, with_parent_context: nil)
+      def in_span(name, attributes: nil, links: nil, start_timestamp: nil, kind: nil, with_parent: nil)
         span = nil
-        span = start_span(name, attributes: attributes, links: links, start_timestamp: start_timestamp, kind: kind, with_parent_context: with_parent_context)
+        span = start_span(name, attributes: attributes, links: links, start_timestamp: start_timestamp, kind: kind, with_parent: with_parent)
         with_span(span) { |s, c| yield s, c }
       rescue Exception => e # rubocop:disable Lint/RescueException
         span&.record_exception(e)
@@ -70,8 +70,9 @@ def start_root_span(name, attributes: nil, links: nil, start_timestamp: nil, kin
       # Parent context can be either passed explicitly, or inferred from currently activated span.
       #
       # @return [Span]
-      def start_span(name, with_parent_context: nil, attributes: nil, links: nil, start_timestamp: nil, kind: nil)
-        span_context = current_span(with_parent_context).context
+      def start_span(name, with_parent: nil, attributes: nil, links: nil, start_timestamp: nil, kind: nil)
+        span_context = current_span(with_parent).context
+
         if span_context.valid?
           Span.new(span_context: span_context)
         else
diff --git a/api/test/opentelemetry/trace/tracer_test.rb b/api/test/opentelemetry/trace/tracer_test.rb
index 1d3991876..b65b9516d 100644
--- a/api/test/opentelemetry/trace/tracer_test.rb
+++ b/api/test/opentelemetry/trace/tracer_test.rb
@@ -92,7 +92,7 @@ def start_span(*)
     end
 
     it 'yields a span with the parent context' do
-      tracer.in_span('op', with_parent_context: parent_context) do |span|
+      tracer.in_span('op', with_parent: parent_context) do |span|
         _(span.context).must_be :valid?
         _(span.context).must_equal(parent_span_context)
       end
@@ -144,7 +144,7 @@ def start_span(*)
     let(:parent) { tracer.start_span('parent') }
 
     it 'returns a valid span with the parent context' do
-      span = tracer.start_span('op', with_parent_context: parent_context)
+      span = tracer.start_span('op', with_parent: parent_context)
       _(span.context).must_be :valid?
       _(span.context).must_equal(parent_span_context)
     end
@@ -156,7 +156,7 @@ def start_span(*)
     end
 
     it 'returns a span with a new context when passed an invalid context' do
-      span = tracer.start_span('op', with_parent_context: invalid_parent_context)
+      span = tracer.start_span('op', with_parent: invalid_parent_context)
       _(span.context).must_be :valid?
       _(span.context).wont_equal(invalid_span_context)
     end
diff --git a/examples/http/server.rb b/examples/http/server.rb
index 3b2d0e980..f9abb743f 100755
--- a/examples/http/server.rb
+++ b/examples/http/server.rb
@@ -45,7 +45,7 @@ def call(env)
         'http.url' => env['REQUEST_URI'],
       },
       kind: :server,
-      with_parent_context: context
+      with_parent: context
     ) do |span|
       # Run application stack
       status, headers, response_body = @app.call(env)
diff --git a/exporter/otlp/test/opentelemetry/exporter/otlp/exporter_test.rb b/exporter/otlp/test/opentelemetry/exporter/otlp/exporter_test.rb
index 72d198752..3cc65cfce 100644
--- a/exporter/otlp/test/opentelemetry/exporter/otlp/exporter_test.rb
+++ b/exporter/otlp/test/opentelemetry/exporter/otlp/exporter_test.rb
@@ -155,7 +155,7 @@
       OpenTelemetry.tracer_provider.add_span_processor(processor)
       root = with_ids(trace_id, root_span_id) { tracer.start_root_span('root', kind: :internal, start_timestamp: start_timestamp).finish(end_timestamp: end_timestamp) }
       root_ctx = tracer.with_span(root) { |_, ctx| ctx }
-      span = with_ids(trace_id, child_span_id) { tracer.start_span('child', with_parent_context: root_ctx, kind: :producer, start_timestamp: start_timestamp + 1, links: [OpenTelemetry::Trace::Link.new(root.context, 'attr' => 4)]) }
+      span = with_ids(trace_id, child_span_id) { tracer.start_span('child', with_parent: root_ctx, kind: :producer, start_timestamp: start_timestamp + 1, links: [OpenTelemetry::Trace::Link.new(root.context, 'attr' => 4)]) }
       span['b'] = true
       span['f'] = 1.1
       span['i'] = 2
@@ -163,11 +163,11 @@
       span['a'] = [3, 4]
       span.status = OpenTelemetry::Trace::Status.new(OpenTelemetry::Trace::Status::ERROR)
       child_ctx = tracer.with_span(span) { |_, ctx| ctx }
-      client = with_ids(trace_id, client_span_id) { tracer.start_span('client', with_parent_context: child_ctx, kind: :client, start_timestamp: start_timestamp + 2).finish(end_timestamp: end_timestamp) }
+      client = with_ids(trace_id, client_span_id) { tracer.start_span('client', with_parent: child_ctx, kind: :client, start_timestamp: start_timestamp + 2).finish(end_timestamp: end_timestamp) }
       client_ctx = tracer.with_span(client) { |_, ctx| ctx }
-      with_ids(trace_id, server_span_id) { other_tracer.start_span('server', with_parent_context: client_ctx, kind: :server, start_timestamp: start_timestamp + 3).finish(end_timestamp: end_timestamp) }
+      with_ids(trace_id, server_span_id) { other_tracer.start_span('server', with_parent: client_ctx, kind: :server, start_timestamp: start_timestamp + 3).finish(end_timestamp: end_timestamp) }
       span.add_event('event', attributes: { 'attr' => 42 }, timestamp: start_timestamp + 4)
-      with_ids(trace_id, consumer_span_id) { tracer.start_span('consumer', with_parent_context: child_ctx, kind: :consumer, start_timestamp: start_timestamp + 5).finish(end_timestamp: end_timestamp) }
+      with_ids(trace_id, consumer_span_id) { tracer.start_span('consumer', with_parent: child_ctx, kind: :consumer, start_timestamp: start_timestamp + 5).finish(end_timestamp: end_timestamp) }
       span.finish(end_timestamp: end_timestamp)
       OpenTelemetry.tracer_provider.shutdown
 
diff --git a/instrumentation/rack/lib/opentelemetry/instrumentation/rack/middlewares/tracer_middleware.rb b/instrumentation/rack/lib/opentelemetry/instrumentation/rack/middlewares/tracer_middleware.rb
index dfc790c4f..d7273914e 100644
--- a/instrumentation/rack/lib/opentelemetry/instrumentation/rack/middlewares/tracer_middleware.rb
+++ b/instrumentation/rack/lib/opentelemetry/instrumentation/rack/middlewares/tracer_middleware.rb
@@ -81,7 +81,7 @@ def create_frontend_span(env, extracted_context)
             return unless config[:record_frontend_span] && !request_start_time.nil?
 
             span = tracer.start_span('http_server.proxy',
-                                     with_parent_context: extracted_context,
+                                     with_parent: extracted_context,
                                      attributes: {
                                        'start_time' => request_start_time.to_f
                                      },
diff --git a/instrumentation/sidekiq/lib/opentelemetry/instrumentation/sidekiq/middlewares/server/tracer_middleware.rb b/instrumentation/sidekiq/lib/opentelemetry/instrumentation/sidekiq/middlewares/server/tracer_middleware.rb
index 4cde99b80..e7f116356 100644
--- a/instrumentation/sidekiq/lib/opentelemetry/instrumentation/sidekiq/middlewares/server/tracer_middleware.rb
+++ b/instrumentation/sidekiq/lib/opentelemetry/instrumentation/sidekiq/middlewares/server/tracer_middleware.rb
@@ -20,7 +20,7 @@ def call(_worker, msg, _queue)
                   'messaging.message_id' => msg['jid'],
                   'messaging.destination' => msg['queue']
                 },
-                with_parent_context: parent_context,
+                with_parent: parent_context,
                 kind: :consumer
               ) do |span|
                 span.add_event('created_at', timestamp: msg['created_at'])
diff --git a/instrumentation/sinatra/lib/opentelemetry/instrumentation/sinatra/middlewares/tracer_middleware.rb b/instrumentation/sinatra/lib/opentelemetry/instrumentation/sinatra/middlewares/tracer_middleware.rb
index b4f7b5e66..518c728b3 100644
--- a/instrumentation/sinatra/lib/opentelemetry/instrumentation/sinatra/middlewares/tracer_middleware.rb
+++ b/instrumentation/sinatra/lib/opentelemetry/instrumentation/sinatra/middlewares/tracer_middleware.rb
@@ -22,7 +22,7 @@ def call(env)
               attributes: { 'http.method' => env['REQUEST_METHOD'],
                             'http.url' => env['PATH_INFO'] },
               kind: :server,
-              with_parent_context: parent_context(env)
+              with_parent: parent_context(env)
             ) do |span|
               app.call(env).tap { |resp| trace_response(span, env, resp) }
             end
diff --git a/sdk/lib/opentelemetry/sdk/trace/tracer.rb b/sdk/lib/opentelemetry/sdk/trace/tracer.rb
index a1340c447..27743653c 100644
--- a/sdk/lib/opentelemetry/sdk/trace/tracer.rb
+++ b/sdk/lib/opentelemetry/sdk/trace/tracer.rb
@@ -30,13 +30,13 @@ def initialize(name, version, tracer_provider)
         end
 
         def start_root_span(name, attributes: nil, links: nil, start_timestamp: nil, kind: nil)
-          start_span(name, with_parent_context: Context.empty, attributes: attributes, links: links, start_timestamp: start_timestamp, kind: kind)
+          start_span(name, with_parent: Context.empty, attributes: attributes, links: links, start_timestamp: start_timestamp, kind: kind)
         end
 
-        def start_span(name, with_parent_context: nil, attributes: nil, links: nil, start_timestamp: nil, kind: nil)
+        def start_span(name, with_parent: nil, attributes: nil, links: nil, start_timestamp: nil, kind: nil)
           name ||= 'empty'
 
-          parent_span_context = current_span(with_parent_context).context
+          parent_span_context = current_span(with_parent).context
           parent_span_context = nil unless parent_span_context.valid?
           parent_span_id = parent_span_context&.span_id
           tracestate = parent_span_context&.tracestate
diff --git a/sdk/test/integration/api_trace_test.rb b/sdk/test/integration/api_trace_test.rb
index c6c0b84cc..122e6a4cd 100644
--- a/sdk/test/integration/api_trace_test.rb
+++ b/sdk/test/integration/api_trace_test.rb
@@ -57,9 +57,9 @@
     end
 
     before do
-      @remote_span = tracer.start_span('remote', with_parent_context: context_with_remote_parent)
+      @remote_span = tracer.start_span('remote', with_parent: context_with_remote_parent)
       tracer.with_span(@remote_span) do |_, ctx|
-        @child_of_remote = tracer.start_span('child1', with_parent_context: ctx)
+        @child_of_remote = tracer.start_span('child1', with_parent: ctx)
       end
     end
 
diff --git a/sdk/test/integration/global_tracer_configurations_test.rb b/sdk/test/integration/global_tracer_configurations_test.rb
index a8c6f1c39..ad1526264 100644
--- a/sdk/test/integration/global_tracer_configurations_test.rb
+++ b/sdk/test/integration/global_tracer_configurations_test.rb
@@ -20,7 +20,7 @@
   let(:finished_spans) { exporter.finished_spans }
 
   before do
-    tracer.in_span('root', with_parent_context: parent_context) do
+    tracer.in_span('root', with_parent: parent_context) do
       tracer.in_span('child1') {}
       tracer.in_span('child2') {}
     end
diff --git a/sdk/test/opentelemetry/sdk/trace/tracer_test.rb b/sdk/test/opentelemetry/sdk/trace/tracer_test.rb
index c18eca574..a958606e2 100644
--- a/sdk/test/opentelemetry/sdk/trace/tracer_test.rb
+++ b/sdk/test/opentelemetry/sdk/trace/tracer_test.rb
@@ -155,46 +155,46 @@
     end
 
     it 'provides a default name' do
-      _(tracer.start_span(nil, with_parent_context: context).name).wont_be_nil
+      _(tracer.start_span(nil, with_parent: context).name).wont_be_nil
     end
 
     it 'returns a valid span' do
-      span = tracer.start_span('op', with_parent_context: context)
+      span = tracer.start_span('op', with_parent: context)
       _(span.context).must_be :valid?
     end
 
     it 'returns a span with the same trace ID as the parent context' do
-      span = tracer.start_span('op', with_parent_context: context)
+      span = tracer.start_span('op', with_parent: context)
       _(span.context.trace_id).must_equal(span_context.trace_id)
     end
 
     it 'returns a span with the parent context span ID' do
-      span = tracer.start_span('op', with_parent_context: context)
+      span = tracer.start_span('op', with_parent: context)
       _(span.parent_span_id).must_equal(span_context.span_id)
     end
 
     it 'returns a span with the parent context tracestate' do
-      span = tracer.start_span('op', with_parent_context: context)
+      span = tracer.start_span('op', with_parent: context)
       _(span.context.tracestate).must_equal(span_context.tracestate)
     end
 
     it 'returns a no-op span if sampler says do not record events' do
       activate_trace_config TraceConfig.new(sampler: Samplers::ALWAYS_OFF)
-      span = tracer.start_span('op', with_parent_context: context)
+      span = tracer.start_span('op', with_parent: context)
       _(span.context.trace_flags).wont_be :sampled?
       _(span).wont_be :recording?
     end
 
     it 'returns an unsampled span if sampler says record, but do not sample' do
       activate_trace_config TraceConfig.new(sampler: record_sampler)
-      span = tracer.start_span('op', with_parent_context: context)
+      span = tracer.start_span('op', with_parent: context)
       _(span.context.trace_flags).wont_be :sampled?
       _(span).must_be :recording?
     end
 
     it 'returns a sampled span if sampler says sample' do
       activate_trace_config TraceConfig.new(sampler: Samplers::ALWAYS_ON)
-      span = tracer.start_span('op', with_parent_context: context)
+      span = tracer.start_span('op', with_parent: context)
       _(span.context.trace_flags).must_be :sampled?
       _(span).must_be :recording?
     end
@@ -208,20 +208,20 @@
       mock_sampler = Minitest::Mock.new
       mock_sampler.expect(:should_sample?, result, [{ trace_id: span_context.trace_id, parent_context: span_context, links: links, name: name, kind: kind, attributes: attributes }])
       activate_trace_config TraceConfig.new(sampler: mock_sampler)
-      tracer.start_span(name, with_parent_context: context, attributes: attributes, links: links, kind: kind)
+      tracer.start_span(name, with_parent: context, attributes: attributes, links: links, kind: kind)
       mock_sampler.verify
     end
 
     it 'returns a no-op span with parent trace ID if tracer has shutdown' do
       tracer_provider.shutdown
-      span = tracer.start_span('op', with_parent_context: context)
+      span = tracer.start_span('op', with_parent: context)
       _(span.context.trace_flags).wont_be :sampled?
       _(span).wont_be :recording?
       _(span.context.trace_id).must_equal(span_context.trace_id)
     end
 
     it 'creates a span with the provided instrumentation library' do
-      span = tracer.start_span('span', with_parent_context: context)
+      span = tracer.start_span('span', with_parent: context)
       _(span.instrumentation_library.name).must_equal('component-tracer')
       _(span.instrumentation_library.version).must_equal('1.0.0')
     end
@@ -232,7 +232,7 @@
       kind = OpenTelemetry::Trace::SpanKind::INTERNAL
       attributes = { '1' => 1 }
       start_timestamp = Time.now
-      span = tracer.start_span(name, with_parent_context: context, attributes: attributes, links: links, kind: kind, start_timestamp: start_timestamp)
+      span = tracer.start_span(name, with_parent: context, attributes: attributes, links: links, kind: kind, start_timestamp: start_timestamp)
       _(span.links).must_equal(links)
       _(span.name).must_equal(name)
       _(span.kind).must_equal(kind)
@@ -248,14 +248,14 @@
       result = Result.new(decision: Decision::RECORD_ONLY, attributes: sampler_attributes)
       mock_sampler.expect(:should_sample?, result, [Hash])
       activate_trace_config TraceConfig.new(sampler: mock_sampler)
-      span = tracer.start_span('op', with_parent_context: context, attributes: { '1' => 0, '2' => 2 })
+      span = tracer.start_span('op', with_parent: context, attributes: { '1' => 0, '2' => 2 })
       _(span.attributes).must_equal('1' => 1, '2' => 2)
     end
 
     it 'uses the context from parent if supplied' do
       parent = tracer.start_root_span('root')
       parent_ctx = tracer.with_span(parent) { |_, ctx| ctx }
-      span = tracer.start_span('child', with_parent_context: parent_ctx)
+      span = tracer.start_span('child', with_parent: parent_ctx)
       _(span.parent_span_id).must_equal(parent.context.span_id)
       _(span.context.trace_id).must_equal(parent.context.trace_id)
     end
@@ -274,7 +274,7 @@
     it 'trims link attributes' do
       activate_trace_config TraceConfig.new(max_attributes_per_link: 1)
       link = OpenTelemetry::Trace::Link.new(OpenTelemetry::Trace::SpanContext.new, '1' => 1, '2' => 2)
-      span = tracer.start_span('op', with_parent_context: context, links: [link])
+      span = tracer.start_span('op', with_parent: context, links: [link])
       _(span.links.first.attributes.size).must_equal(1)
     end
 
@@ -282,7 +282,7 @@
       activate_trace_config TraceConfig.new(max_links_count: 1)
       link1 = OpenTelemetry::Trace::Link.new(OpenTelemetry::Trace::SpanContext.new, '1' => 1)
       link2 = OpenTelemetry::Trace::Link.new(OpenTelemetry::Trace::SpanContext.new, '2' => 2)
-      span = tracer.start_span('op', with_parent_context: context, links: [link1, link2])
+      span = tracer.start_span('op', with_parent: context, links: [link1, link2])
       _(span.links.size).must_equal(1)
       _(span.links.first).must_equal(link2)
     end

From 9071e19bcb4ad697bda8eaf33cb9d66440395798 Mon Sep 17 00:00:00 2001
From: Matthew Wear <matthew.wear@gmail.com>
Date: Thu, 17 Sep 2020 20:10:20 -0700
Subject: [PATCH 3/8] docs: restore with_parent tracer docs

---
 api/lib/opentelemetry/trace/tracer.rb | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/api/lib/opentelemetry/trace/tracer.rb b/api/lib/opentelemetry/trace/tracer.rb
index f1fd19854..8388d6257 100644
--- a/api/lib/opentelemetry/trace/tracer.rb
+++ b/api/lib/opentelemetry/trace/tracer.rb
@@ -69,6 +69,8 @@ def start_root_span(name, attributes: nil, links: nil, start_timestamp: nil, kin
       #
       # Parent context can be either passed explicitly, or inferred from currently activated span.
       #
+      # @param [optional Context] with_parent Explicitly managed parent context
+      #
       # @return [Span]
       def start_span(name, with_parent: nil, attributes: nil, links: nil, start_timestamp: nil, kind: nil)
         span_context = current_span(with_parent).context

From b53b1ed3e767b0c945d47fcb5276d71078b76588 Mon Sep 17 00:00:00 2001
From: Matthew Wear <matthew.wear@gmail.com>
Date: Thu, 17 Sep 2020 20:20:50 -0700
Subject: [PATCH 4/8] fix: resurrect tracer benchmarks

---
 api/benchmarks/tracer_bench.rb | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/api/benchmarks/tracer_bench.rb b/api/benchmarks/tracer_bench.rb
index 686f1e8f3..c197237a8 100644
--- a/api/benchmarks/tracer_bench.rb
+++ b/api/benchmarks/tracer_bench.rb
@@ -10,6 +10,7 @@
 tracer = OpenTelemetry::Trace::Tracer.new
 
 parent_span = tracer.start_span('parent')
+parent_context = tracer.with_span(parent_span) { |_, c| c }
 
 attributes = {
   'component' => 'rack',
@@ -32,7 +33,7 @@
   end
 
   x.report 'start span with parent context' do
-    span = tracer.start_span('test_span', with_parent: parent_span.context)
+    span = tracer.start_span('test_span', with_parent: parent_context)
     span.finish
   end
 

From 13ce04cfc894bf92b0ce61a2130cbdcd7b6ec5e1 Mon Sep 17 00:00:00 2001
From: Matthew Wear <matthew.wear@gmail.com>
Date: Thu, 17 Sep 2020 20:41:05 -0700
Subject: [PATCH 5/8] feat: add Tracer#context_with_span convenience method

---
 api/lib/opentelemetry/trace/tracer.rb       |  9 +++++++++
 api/test/opentelemetry/trace/tracer_test.rb | 16 ++++++++++++++++
 2 files changed, 25 insertions(+)

diff --git a/api/lib/opentelemetry/trace/tracer.rb b/api/lib/opentelemetry/trace/tracer.rb
index 8388d6257..addc10e22 100644
--- a/api/lib/opentelemetry/trace/tracer.rb
+++ b/api/lib/opentelemetry/trace/tracer.rb
@@ -21,6 +21,15 @@ def current_span(context = nil)
         context.value(CURRENT_SPAN_KEY) || Span::INVALID
       end
 
+      # Returns a context containing the span, derived from the optional parent
+      # context, or the current context if one was not provided.
+      #
+      # @param [optional Context] context The context to use as the parent for
+      #  the returned context
+      def context_with_span(span, context = Context.current)
+        context.set_value(CURRENT_SPAN_KEY, span)
+      end
+
       # This is a helper for the default use-case of extending the current trace with a span.
       #
       # With this helper:
diff --git a/api/test/opentelemetry/trace/tracer_test.rb b/api/test/opentelemetry/trace/tracer_test.rb
index b65b9516d..f915d761a 100644
--- a/api/test/opentelemetry/trace/tracer_test.rb
+++ b/api/test/opentelemetry/trace/tracer_test.rb
@@ -161,4 +161,20 @@ def start_span(*)
       _(span.context).wont_equal(invalid_span_context)
     end
   end
+
+  describe '#context_with_span' do
+    it 'returns a context containing span' do
+      span = tracer.start_span('test')
+      ctx = tracer.context_with_span(span)
+      _(tracer.current_span(ctx)).must_equal(span)
+    end
+
+    it 'returns a context containing span' do
+      parent_ctx = OpenTelemetry::Context.empty.set_value('foo', 'bar')
+      span = tracer.start_span('test')
+      ctx = tracer.context_with_span(span, parent_ctx)
+      _(tracer.current_span(ctx)).must_equal(span)
+      _(ctx.value('foo')).must_equal('bar')
+    end
+  end
 end

From d5e20f08974c37ad41e0584e507d3b81dc124b0d Mon Sep 17 00:00:00 2001
From: Matthew Wear <matthew.wear@gmail.com>
Date: Thu, 17 Sep 2020 20:52:14 -0700
Subject: [PATCH 6/8] refactor: update tests to use context_with_span
 convenience method

---
 api/benchmarks/tracer_bench.rb                      |  2 +-
 .../opentelemetry/exporter/otlp/exporter_test.rb    |  6 +++---
 sdk/test/integration/api_trace_test.rb              | 13 +++++--------
 3 files changed, 9 insertions(+), 12 deletions(-)

diff --git a/api/benchmarks/tracer_bench.rb b/api/benchmarks/tracer_bench.rb
index c197237a8..5a0f71401 100644
--- a/api/benchmarks/tracer_bench.rb
+++ b/api/benchmarks/tracer_bench.rb
@@ -10,7 +10,7 @@
 tracer = OpenTelemetry::Trace::Tracer.new
 
 parent_span = tracer.start_span('parent')
-parent_context = tracer.with_span(parent_span) { |_, c| c }
+parent_context = tracer.context_with_span(parent_span)
 
 attributes = {
   'component' => 'rack',
diff --git a/exporter/otlp/test/opentelemetry/exporter/otlp/exporter_test.rb b/exporter/otlp/test/opentelemetry/exporter/otlp/exporter_test.rb
index 3cc65cfce..7ff9b7ef4 100644
--- a/exporter/otlp/test/opentelemetry/exporter/otlp/exporter_test.rb
+++ b/exporter/otlp/test/opentelemetry/exporter/otlp/exporter_test.rb
@@ -154,7 +154,7 @@
 
       OpenTelemetry.tracer_provider.add_span_processor(processor)
       root = with_ids(trace_id, root_span_id) { tracer.start_root_span('root', kind: :internal, start_timestamp: start_timestamp).finish(end_timestamp: end_timestamp) }
-      root_ctx = tracer.with_span(root) { |_, ctx| ctx }
+      root_ctx = tracer.context_with_span(root)
       span = with_ids(trace_id, child_span_id) { tracer.start_span('child', with_parent: root_ctx, kind: :producer, start_timestamp: start_timestamp + 1, links: [OpenTelemetry::Trace::Link.new(root.context, 'attr' => 4)]) }
       span['b'] = true
       span['f'] = 1.1
@@ -162,9 +162,9 @@
       span['s'] = 'val'
       span['a'] = [3, 4]
       span.status = OpenTelemetry::Trace::Status.new(OpenTelemetry::Trace::Status::ERROR)
-      child_ctx = tracer.with_span(span) { |_, ctx| ctx }
+      child_ctx = tracer.context_with_span(span)
       client = with_ids(trace_id, client_span_id) { tracer.start_span('client', with_parent: child_ctx, kind: :client, start_timestamp: start_timestamp + 2).finish(end_timestamp: end_timestamp) }
-      client_ctx = tracer.with_span(client) { |_, ctx| ctx }
+      client_ctx = tracer.context_with_span(client)
       with_ids(trace_id, server_span_id) { other_tracer.start_span('server', with_parent: client_ctx, kind: :server, start_timestamp: start_timestamp + 3).finish(end_timestamp: end_timestamp) }
       span.add_event('event', attributes: { 'attr' => 42 }, timestamp: start_timestamp + 4)
       with_ids(trace_id, consumer_span_id) { tracer.start_span('consumer', with_parent: child_ctx, kind: :consumer, start_timestamp: start_timestamp + 5).finish(end_timestamp: end_timestamp) }
diff --git a/sdk/test/integration/api_trace_test.rb b/sdk/test/integration/api_trace_test.rb
index 122e6a4cd..c98d86878 100644
--- a/sdk/test/integration/api_trace_test.rb
+++ b/sdk/test/integration/api_trace_test.rb
@@ -58,9 +58,7 @@
 
     before do
       @remote_span = tracer.start_span('remote', with_parent: context_with_remote_parent)
-      tracer.with_span(@remote_span) do |_, ctx|
-        @child_of_remote = tracer.start_span('child1', with_parent: ctx)
-      end
+      @child_of_remote = tracer.start_span('child1', with_parent: tracer.context_with_span(@remote_span))
     end
 
     it 'has a child' do
@@ -70,11 +68,10 @@
 
   describe 'tracing child-of-local spans' do
     before do
-      tracer.in_span('local') do |parent|
-        @local_parent_span = parent
-        tracer.in_span('child1') do |child|
-          @child_of_local = child
-        end
+      @local_parent_span = tracer.start_span('local')
+      parent_ctx = tracer.context_with_span(@local_parent_span)
+      tracer.in_span('child1', with_parent: parent_ctx) do |child|
+        @child_of_local = child
       end
     end
 

From 301c4ae7c9777849490df7b05727920818689261 Mon Sep 17 00:00:00 2001
From: Matthew Wear <matthew.wear@gmail.com>
Date: Tue, 22 Sep 2020 16:29:00 -0700
Subject: [PATCH 7/8] feat: pass parent context to span processors

---
 .../sdk/trace/export/batch_span_processor.rb     |  2 +-
 .../sdk/trace/export/simple_span_processor.rb    |  4 +++-
 .../sdk/trace/multi_span_processor.rb            |  6 ++++--
 .../sdk/trace/noop_span_processor.rb             |  4 +++-
 sdk/lib/opentelemetry/sdk/trace/span.rb          |  4 ++--
 sdk/lib/opentelemetry/sdk/trace/tracer.rb        |  8 +++++---
 .../trace/export/simple_span_processor_test.rb   | 11 ++++++-----
 .../sdk/trace/multi_span_processor_test.rb       |  7 ++++---
 .../sdk/trace/noop_span_processor_test.rb        |  3 ++-
 sdk/test/opentelemetry/sdk/trace/span_test.rb    | 16 +++++++++-------
 .../sdk/trace/tracer_provider_test.rb            |  4 ++--
 11 files changed, 41 insertions(+), 28 deletions(-)

diff --git a/sdk/lib/opentelemetry/sdk/trace/export/batch_span_processor.rb b/sdk/lib/opentelemetry/sdk/trace/export/batch_span_processor.rb
index a67b0e92e..543d95e09 100644
--- a/sdk/lib/opentelemetry/sdk/trace/export/batch_span_processor.rb
+++ b/sdk/lib/opentelemetry/sdk/trace/export/batch_span_processor.rb
@@ -62,7 +62,7 @@ def initialize(exporter:,
           end
 
           # does nothing for this processor
-          def on_start(span)
+          def on_start(span, parent_context)
             # noop
           end
 
diff --git a/sdk/lib/opentelemetry/sdk/trace/export/simple_span_processor.rb b/sdk/lib/opentelemetry/sdk/trace/export/simple_span_processor.rb
index 2150f7ffc..35d9993bc 100644
--- a/sdk/lib/opentelemetry/sdk/trace/export/simple_span_processor.rb
+++ b/sdk/lib/opentelemetry/sdk/trace/export/simple_span_processor.rb
@@ -33,7 +33,9 @@ def initialize(span_exporter)
           # not throw or block the execution thread.
           #
           # @param [Span] span the {Span} that just started.
-          def on_start(span)
+          # @param [Context] parent_context the parent {Context} of the newly
+          #  started span.
+          def on_start(span, parent_context)
             # Do nothing.
           end
 
diff --git a/sdk/lib/opentelemetry/sdk/trace/multi_span_processor.rb b/sdk/lib/opentelemetry/sdk/trace/multi_span_processor.rb
index 2cc585196..282ae5c0f 100644
--- a/sdk/lib/opentelemetry/sdk/trace/multi_span_processor.rb
+++ b/sdk/lib/opentelemetry/sdk/trace/multi_span_processor.rb
@@ -26,8 +26,10 @@ def initialize(span_processors)
         # not throw or block the execution thread.
         #
         # @param [Span] span the {Span} that just started.
-        def on_start(span)
-          @span_processors.each { |processor| processor.on_start(span) }
+        # @param [Context] parent_context the parent {Context} of the newly
+        #  started span.
+        def on_start(span, parent_context)
+          @span_processors.each { |processor| processor.on_start(span, parent_context) }
         end
 
         # Called when a {Span} is ended, if the {Span#recording?}
diff --git a/sdk/lib/opentelemetry/sdk/trace/noop_span_processor.rb b/sdk/lib/opentelemetry/sdk/trace/noop_span_processor.rb
index e71d579af..b9d9a60aa 100644
--- a/sdk/lib/opentelemetry/sdk/trace/noop_span_processor.rb
+++ b/sdk/lib/opentelemetry/sdk/trace/noop_span_processor.rb
@@ -22,7 +22,9 @@ class NoopSpanProcessor
         # not throw or block the execution thread.
         #
         # @param [Span] span the {Span} that just started.
-        def on_start(span); end
+        # @param [Context] parent_context the parent {Context} of the newly
+        #  started span.
+        def on_start(span, parent_context); end
 
         # Called when a {Span} is ended, if the {Span#recording?}
         # returns true.
diff --git a/sdk/lib/opentelemetry/sdk/trace/span.rb b/sdk/lib/opentelemetry/sdk/trace/span.rb
index 546cfd71c..180206e60 100644
--- a/sdk/lib/opentelemetry/sdk/trace/span.rb
+++ b/sdk/lib/opentelemetry/sdk/trace/span.rb
@@ -241,7 +241,7 @@ def to_span_data
         end
 
         # @api private
-        def initialize(context, name, kind, parent_span_id, trace_config, span_processor, attributes, links, start_timestamp, resource, instrumentation_library) # rubocop:disable Metrics/AbcSize
+        def initialize(context, parent_context, name, kind, parent_span_id, trace_config, span_processor, attributes, links, start_timestamp, resource, instrumentation_library) # rubocop:disable Metrics/AbcSize
           super(span_context: context)
           @mutex = Mutex.new
           @name = name
@@ -262,7 +262,7 @@ def initialize(context, name, kind, parent_span_id, trace_config, span_processor
           trim_span_attributes(@attributes)
           @events = nil
           @links = trim_links(links, trace_config.max_links_count, trace_config.max_attributes_per_link)
-          @span_processor.on_start(self)
+          @span_processor.on_start(self, parent_context)
         end
 
         # TODO: Java implementation overrides finalize to log if a span isn't finished.
diff --git a/sdk/lib/opentelemetry/sdk/trace/tracer.rb b/sdk/lib/opentelemetry/sdk/trace/tracer.rb
index 27743653c..1d85bf743 100644
--- a/sdk/lib/opentelemetry/sdk/trace/tracer.rb
+++ b/sdk/lib/opentelemetry/sdk/trace/tracer.rb
@@ -33,9 +33,10 @@ def start_root_span(name, attributes: nil, links: nil, start_timestamp: nil, kin
           start_span(name, with_parent: Context.empty, attributes: attributes, links: links, start_timestamp: start_timestamp, kind: kind)
         end
 
-        def start_span(name, with_parent: nil, attributes: nil, links: nil, start_timestamp: nil, kind: nil)
+        def start_span(name, with_parent: nil, attributes: nil, links: nil, start_timestamp: nil, kind: nil) # rubocop:disable Metrics/AbcSize
           name ||= 'empty'
 
+          with_parent ||= Context.current
           parent_span_context = current_span(with_parent).context
           parent_span_context = nil unless parent_span_context.valid?
           parent_span_id = parent_span_context&.span_id
@@ -44,18 +45,19 @@ def start_span(name, with_parent: nil, attributes: nil, links: nil, start_timest
           trace_id ||= OpenTelemetry::Trace.generate_trace_id
           sampler = tracer_provider.active_trace_config.sampler
           result = sampler.should_sample?(trace_id: trace_id, parent_context: parent_span_context, links: links, name: name, kind: kind, attributes: attributes)
-          internal_create_span(result, name, kind, trace_id, parent_span_id, attributes, links, start_timestamp, tracestate)
+          internal_create_span(result, name, kind, trace_id, parent_span_id, attributes, links, start_timestamp, tracestate, with_parent)
         end
 
         private
 
-        def internal_create_span(result, name, kind, trace_id, parent_span_id, attributes, links, start_timestamp, tracestate) # rubocop:disable Metrics/AbcSize
+        def internal_create_span(result, name, kind, trace_id, parent_span_id, attributes, links, start_timestamp, tracestate, parent_context) # rubocop:disable Metrics/AbcSize
           if result.recording? && !tracer_provider.stopped?
             trace_flags = result.sampled? ? OpenTelemetry::Trace::TraceFlags::SAMPLED : OpenTelemetry::Trace::TraceFlags::DEFAULT
             context = OpenTelemetry::Trace::SpanContext.new(trace_id: trace_id, trace_flags: trace_flags, tracestate: tracestate)
             attributes = attributes&.merge(result.attributes) || result.attributes
             Span.new(
               context,
+              parent_context,
               name,
               kind,
               parent_span_id,
diff --git a/sdk/test/opentelemetry/sdk/trace/export/simple_span_processor_test.rb b/sdk/test/opentelemetry/sdk/trace/export/simple_span_processor_test.rb
index 65d137af6..37104e5ef 100644
--- a/sdk/test/opentelemetry/sdk/trace/export/simple_span_processor_test.rb
+++ b/sdk/test/opentelemetry/sdk/trace/export/simple_span_processor_test.rb
@@ -30,10 +30,11 @@ def mock.nil?
 
   let(:stub_span_unrecorded) { stub_span_builder(recording: false) }
   let(:stub_span_recorded)   { stub_span_builder(recording: true) }
+  let(:parent_context) { OpenTelemetry::Context.empty }
   let(:processor) { export::SimpleSpanProcessor.new(mock_span_exporter) }
 
   it 'accepts calls to #on_start' do
-    processor.on_start(stub_span_recorded)
+    processor.on_start(stub_span_recorded, parent_context)
   end
 
   it 'accepts calls to #force_flush' do
@@ -43,13 +44,13 @@ def mock.nil?
   it 'forwards recorded spans from #on_finish' do
     mock_span_exporter.expect :export, export::SUCCESS, [Array]
 
-    processor.on_start(stub_span_recorded)
+    processor.on_start(stub_span_recorded, parent_context)
     processor.on_finish(stub_span_recorded)
     mock_span_exporter.verify
   end
 
   it 'ignores unrecorded spans in #on_finish' do
-    processor.on_start(stub_span_unrecorded)
+    processor.on_start(stub_span_unrecorded, parent_context)
     processor.on_finish(stub_span_unrecorded)
     mock_span_exporter.verify
   end
@@ -67,7 +68,7 @@ def mock.nil?
     mock_span.expect :context, mock_span_context
     mock_span.expect :to_span_data, nil
 
-    processor_noop.on_start(mock_span)
+    processor_noop.on_start(mock_span, parent_context)
     processor_noop.on_finish(mock_span)
     mock_span.verify
   end
@@ -83,7 +84,7 @@ def raising_exporter.export(_)
       raising_exporter
     )
 
-    processor_with_raising_exporter.on_start(stub_span_recorded)
+    processor_with_raising_exporter.on_start(stub_span_recorded, parent_context)
 
     logger_mock = Minitest::Mock.new
     logger_mock.expect :error, nil, [/ArgumentError/]
diff --git a/sdk/test/opentelemetry/sdk/trace/multi_span_processor_test.rb b/sdk/test/opentelemetry/sdk/trace/multi_span_processor_test.rb
index df311e04a..65af4c87a 100644
--- a/sdk/test/opentelemetry/sdk/trace/multi_span_processor_test.rb
+++ b/sdk/test/opentelemetry/sdk/trace/multi_span_processor_test.rb
@@ -10,6 +10,7 @@
   let(:mock_processor1)    { Minitest::Mock.new }
   let(:mock_processor2)    { Minitest::Mock.new }
   let(:span)               { 'dummy span' }
+  let(:context)            { 'dummy context' }
 
   let(:processor) do
     OpenTelemetry::SDK::Trace::MultiSpanProcessor.new(
@@ -18,10 +19,10 @@
   end
 
   it 'implements #on_start' do
-    mock_processor1.expect :on_start, nil, [span]
-    mock_processor2.expect :on_start, nil, [span]
+    mock_processor1.expect :on_start, nil, [span, context]
+    mock_processor2.expect :on_start, nil, [span, context]
 
-    processor.on_start(span)
+    processor.on_start(span, context)
 
     mock_processor1.verify
     mock_processor2.verify
diff --git a/sdk/test/opentelemetry/sdk/trace/noop_span_processor_test.rb b/sdk/test/opentelemetry/sdk/trace/noop_span_processor_test.rb
index 1c83fa547..6318af09f 100644
--- a/sdk/test/opentelemetry/sdk/trace/noop_span_processor_test.rb
+++ b/sdk/test/opentelemetry/sdk/trace/noop_span_processor_test.rb
@@ -9,9 +9,10 @@
 describe OpenTelemetry::SDK::Trace::NoopSpanProcessor do
   let(:processor) { OpenTelemetry::SDK::Trace::NoopSpanProcessor.instance }
   let(:span)      { nil }
+  let(:context)   { nil }
 
   it 'implements #on_start' do
-    processor.on_start(span)
+    processor.on_start(span, context)
   end
 
   it 'implements #on_finish' do
diff --git a/sdk/test/opentelemetry/sdk/trace/span_test.rb b/sdk/test/opentelemetry/sdk/trace/span_test.rb
index c23c902c6..cef4c54ac 100644
--- a/sdk/test/opentelemetry/sdk/trace/span_test.rb
+++ b/sdk/test/opentelemetry/sdk/trace/span_test.rb
@@ -12,6 +12,7 @@
   NoopSpanProcessor = OpenTelemetry::SDK::Trace::NoopSpanProcessor
   SpanKind = OpenTelemetry::Trace::SpanKind
   Status = OpenTelemetry::Trace::Status
+  Context = OpenTelemetry::Context
 
   let(:context) { OpenTelemetry::Trace::SpanContext.new }
   let(:span_processor) { NoopSpanProcessor.instance }
@@ -26,7 +27,7 @@
     )
   end
   let(:span) do
-    Span.new(context, 'name', SpanKind::INTERNAL, nil, trace_config,
+    Span.new(context, Context.empty, 'name', SpanKind::INTERNAL, nil, trace_config,
              span_processor, nil, nil, Time.now, nil, nil)
   end
 
@@ -253,7 +254,8 @@
 
     it 'calls the span processor #on_finish callback' do
       mock_span_processor.expect(:on_start, nil) { |_| true }
-      span = Span.new(context, 'name', SpanKind::INTERNAL, nil, trace_config,
+      span = Span.new(context, Context.empty,
+                      'name', SpanKind::INTERNAL, nil, trace_config,
                       mock_span_processor, nil, nil, Time.now, nil, nil)
       mock_span_processor.expect(:on_finish, nil, [span])
       span.finish
@@ -282,7 +284,7 @@
     it 'calls the span processor #on_start callback' do
       yielded_span = nil
       mock_span_processor.expect(:on_start, nil) { |s| yielded_span = s }
-      span = Span.new(context, 'name', SpanKind::INTERNAL, nil, trace_config,
+      span = Span.new(context, Context.empty, 'name', SpanKind::INTERNAL, nil, trace_config,
                       mock_span_processor, nil, nil, Time.now, nil, nil)
       _(yielded_span).must_equal(span)
       mock_span_processor.verify
@@ -290,7 +292,7 @@
 
     it 'trims excess attributes' do
       attributes = { 'foo': 'bar', 'other': 'attr' }
-      span = Span.new(context, 'name', SpanKind::INTERNAL, nil, trace_config,
+      span = Span.new(context, Context.empty, 'name', SpanKind::INTERNAL, nil, trace_config,
                       span_processor, attributes, nil, Time.now, nil, nil)
       _(span.to_span_data.total_recorded_attributes).must_equal(2)
       _(span.attributes.length).must_equal(1)
@@ -298,21 +300,21 @@
 
     it 'counts attributes' do
       attributes = { 'foo': 'bar', 'other': 'attr' }
-      span = Span.new(context, 'name', SpanKind::INTERNAL, nil, trace_config,
+      span = Span.new(context, Context.empty, 'name', SpanKind::INTERNAL, nil, trace_config,
                       span_processor, attributes, nil, Time.now, nil, nil)
       _(span.to_span_data.total_recorded_attributes).must_equal(2)
     end
 
     it 'counts links' do
       links = [OpenTelemetry::Trace::Link.new(context), OpenTelemetry::Trace::Link.new(context)]
-      span = Span.new(context, 'name', SpanKind::INTERNAL, nil, trace_config,
+      span = Span.new(context, Context.empty, 'name', SpanKind::INTERNAL, nil, trace_config,
                       span_processor, nil, links, Time.now, nil, nil)
       _(span.to_span_data.total_recorded_links).must_equal(2)
     end
 
     it 'trims excess links' do
       links = [OpenTelemetry::Trace::Link.new(context), OpenTelemetry::Trace::Link.new(context)]
-      span = Span.new(context, 'name', SpanKind::INTERNAL, nil, trace_config,
+      span = Span.new(context, Context.empty, 'name', SpanKind::INTERNAL, nil, trace_config,
                       span_processor, nil, links, Time.now, nil, nil)
       _(span.links.size).must_equal(1)
     end
diff --git a/sdk/test/opentelemetry/sdk/trace/tracer_provider_test.rb b/sdk/test/opentelemetry/sdk/trace/tracer_provider_test.rb
index 471528180..c139bc6a1 100644
--- a/sdk/test/opentelemetry/sdk/trace/tracer_provider_test.rb
+++ b/sdk/test/opentelemetry/sdk/trace/tracer_provider_test.rb
@@ -57,7 +57,7 @@
 
     it 'adds the span processor to the active span processors' do
       mock_span_processor = Minitest::Mock.new
-      mock_span_processor.expect(:on_start, nil, [Span])
+      mock_span_processor.expect(:on_start, nil, [Span, Context])
       mock_span_processor.expect(:on_finish, nil, [Span])
       tracer_provider.add_span_processor(mock_span_processor)
       tracer_provider.tracer.in_span('span') {}
@@ -67,7 +67,7 @@
     it 'adds multiple span processors to the active span processors' do
       mock_processors = Array.new(2) { MiniTest::Mock.new }
       mock_processors.each do |p|
-        p.expect(:on_start, nil, [Span])
+        p.expect(:on_start, nil, [Span, Context])
         p.expect(:on_finish, nil, [Span])
         tracer_provider.add_span_processor(p)
       end

From 0adf482b3fc1770ea384f7fd832367ed8ee3ac47 Mon Sep 17 00:00:00 2001
From: Matthew Wear <matthew.wear@gmail.com>
Date: Tue, 29 Sep 2020 11:34:35 -0700
Subject: [PATCH 8/8] refactor: use named parameter for context in
 context_with_span method

---
 api/lib/opentelemetry/trace/tracer.rb       | 4 ++--
 api/test/opentelemetry/trace/tracer_test.rb | 2 +-
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/api/lib/opentelemetry/trace/tracer.rb b/api/lib/opentelemetry/trace/tracer.rb
index addc10e22..78d8c0560 100644
--- a/api/lib/opentelemetry/trace/tracer.rb
+++ b/api/lib/opentelemetry/trace/tracer.rb
@@ -26,8 +26,8 @@ def current_span(context = nil)
       #
       # @param [optional Context] context The context to use as the parent for
       #  the returned context
-      def context_with_span(span, context = Context.current)
-        context.set_value(CURRENT_SPAN_KEY, span)
+      def context_with_span(span, parent_context: Context.current)
+        parent_context.set_value(CURRENT_SPAN_KEY, span)
       end
 
       # This is a helper for the default use-case of extending the current trace with a span.
diff --git a/api/test/opentelemetry/trace/tracer_test.rb b/api/test/opentelemetry/trace/tracer_test.rb
index f915d761a..698a76701 100644
--- a/api/test/opentelemetry/trace/tracer_test.rb
+++ b/api/test/opentelemetry/trace/tracer_test.rb
@@ -172,7 +172,7 @@ def start_span(*)
     it 'returns a context containing span' do
       parent_ctx = OpenTelemetry::Context.empty.set_value('foo', 'bar')
       span = tracer.start_span('test')
-      ctx = tracer.context_with_span(span, parent_ctx)
+      ctx = tracer.context_with_span(span, parent_context: parent_ctx)
       _(tracer.current_span(ctx)).must_equal(span)
       _(ctx.value('foo')).must_equal('bar')
     end