Add script name to resource for Sinatra if available

lib/ddtrace/contrib/sinatra/tracer.rb

@@ -30,11 +30,19 @@ module Tracer
 
         option :tracer, default: Datadog.tracer
 
+        option :resource_script_names, default: false
+
         def route(verb, action, *)
           # Keep track of the route name when the app is instantiated for an
           # incoming request.
           condition do
-            @datadog_route = action
+            # If the option to prepend script names is enabled, then
+            # prepend the script name from the request onto the action.
+            @datadog_route = if Datadog.configuration[:sinatra][:resource_script_names]
+                               "#{request.script_name}#{action}"
+                             else
+                               action
+                             end
           end
 
           super

test/contrib/sinatra/first_test_app.rb

@@ -0,0 +1,11 @@
+require 'contrib/sinatra/tracer_test_base'
+
+class MultiAppTest < TracerTestBase
+  class FirstTestApp < Sinatra::Base
+    register Datadog::Contrib::Sinatra::Tracer
+
+    get '/endpoint' do
+      '1'
+    end
+  end
+end

test/contrib/sinatra/multi_app_test.rb

@@ -0,0 +1,106 @@
+require 'contrib/sinatra/tracer_test_base'
+require 'contrib/sinatra/first_test_app'
+require 'contrib/sinatra/second_test_app'
+
+class MultiAppTest < TracerTestBase
+  def app
+    @use_multi_app ? multi_app : single_app
+  end
+
+  def multi_app
+    Rack::Builder.new do
+      map '/one' do
+        run FirstTestApp
+      end
+
+      map '/two' do
+        run SecondTestApp
+      end
+    end.to_app
+  end
+
+  def single_app
+    FirstTestApp
+  end
+
+  def setup
+    @writer = FauxWriter.new
+    FirstTestApp.set :datadog_test_writer, @writer
+    SecondTestApp.set :datadog_test_writer, @writer
+
+    tracer = Datadog::Tracer.new(writer: @writer, enabled: true)
+    Datadog.configuration[:sinatra][:tracer] = tracer
+
+    super
+  end
+
+  def teardown
+    disable_script_names!
+  end
+
+  def enable_script_names!
+    Datadog.configuration[:sinatra][:resource_script_names] = true
+  end
+
+  def disable_script_names!
+    Datadog.configuration[:sinatra][:resource_script_names] = false
+  end
+
+  # Test for when a single, normal app is setup.
+  # script_name is ''
+  # (To make sure we aren't breaking normal Sinatra apps.)
+  def test_resource_name_without_script_name
+    @use_multi_app = false
+    enable_script_names!
+
+    get '/endpoint'
+
+    spans = @writer.spans.select { |s| s.name == 'sinatra.request' }
+    assert_equal(1, spans.length)
+
+    spans.first.tap do |span|
+      assert_equal('GET /endpoint', span.resource)
+    end
+  end
+
+  # Test for when a multi-app is setup.
+  # script_name is the sub-app's base prefix.
+  # e.g. '/one' in this example.
+  # (To make sure we aren't adding script names when disabled.)
+  def test_resource_name_with_script_name_disabled
+    @use_multi_app = true
+    disable_script_names!
+
+    get '/one/endpoint'
+
+    spans = @writer.spans.select { |s| s.name == 'sinatra.request' }
+    assert_equal(1, spans.length)
+
+    spans.first.tap do |span|
+      assert_equal('GET /endpoint', span.resource)
+    end
+  end
+
+  # Test for when a multi-app is setup.
+  # script_name is the sub-app's base prefix.
+  # e.g. '/one' and '/two' in this example.
+  # (To make sure we are adding script names when enabled.)
+  def test_resource_name_with_script_name
+    @use_multi_app = true
+    enable_script_names!
+
+    get '/one/endpoint'
+    get '/two/endpoint'
+
+    spans = @writer.spans.select { |s| s.name == 'sinatra.request' }
+    assert_equal(2, spans.length)
+
+    spans.first.tap do |span|
+      assert_equal('GET /one/endpoint', span.resource)
+    end
+
+    spans.last.tap do |span|
+      assert_equal('GET /two/endpoint', span.resource)
+    end
+  end
+end

test/contrib/sinatra/second_test_app.rb

@@ -0,0 +1,11 @@
+require 'contrib/sinatra/tracer_test_base'
+
+class MultiAppTest < TracerTestBase
+  class SecondTestApp < Sinatra::Base
+    register Datadog::Contrib::Sinatra::Tracer
+
+    get '/endpoint' do
+      '2'
+    end
+  end
+end