Ensure clean environment for RSpec integration tests (#1420)

spec/ddtrace/contrib/rspec/instrumentation_spec.rb

@@ -5,36 +5,35 @@
 require 'ddtrace'
 
 RSpec.describe 'RSpec hooks' do
-  extend ConfigurationHelpers
-
   let(:configuration_options) { {} }
 
-  around do |example|
-    old_configuration = ::RSpec.configuration
-    ::RSpec.configuration = ::RSpec::Core::Configuration.new
-
+  before do
     Datadog.configure do |c|
       c.use :rspec, configuration_options
     end
-    example.run
+  end
+
+  # Yields to a block in a new RSpec global context. All RSpec
+  # test configuration and execution should be wrapped in this method.
+  def with_new_rspec_environment
+    old_configuration = ::RSpec.configuration
+    old_world = ::RSpec.world
+    ::RSpec.configuration = ::RSpec::Core::Configuration.new
+    ::RSpec.world = ::RSpec::Core::World.new
 
-    RSpec.configuration = old_configuration
-    Datadog.configuration.reset!
+    yield
+  ensure
+    ::RSpec.configuration = old_configuration
+    ::RSpec.world = old_world
   end
 
   it 'creates span for example' do
-    spans = []
-    spec = RSpec.describe 'some test' do
-      let(:active_span) { Datadog.configuration[:rspec][:tracer].active_span }
-
-      it 'foo' do
-        spans << active_span
-      end
+    spec = with_new_rspec_environment do
+      RSpec.describe 'some test' do
+        it 'foo' do; end
+      end.tap(&:run)
     end
-    spec.run
 
-    expect(spans.count).to eq(1)
-    span = spans.first
     expect(span.span_type).to eq(Datadog::Ext::AppTypes::TEST)
     expect(span.name).to eq(Datadog::Contrib::RSpec::Ext::OPERATION_NAME)
     expect(span.resource).to eq('some test foo')
@@ -47,53 +46,42 @@
   end
 
   it 'creates spans for several examples' do
-    spans = []
     num_examples = 20
-    spec = RSpec.describe 'many tests' do
-      let(:active_span) { Datadog.configuration[:rspec][:tracer].active_span }
-
-      num_examples.times do |n|
-        it n do
-          spans << active_span
+    with_new_rspec_environment do
+      RSpec.describe 'many tests' do
+        num_examples.times do |n|
+          it n do; end
         end
-      end
+      end.run
     end
-    spec.run
 
-    expect(spans.count).to eq(num_examples)
+    expect(spans).to have(num_examples).items
   end
 
   it 'creates span for unnamed examples' do
-    spans = []
-    spec = RSpec.describe 'some unnamed test' do
-      let(:active_span) { Datadog.configuration[:rspec][:tracer].active_span }
-
-      it { spans << active_span }
+    with_new_rspec_environment do
+      RSpec.describe 'some unnamed test' do
+        it do; end
+      end.run
     end
-    spec.run
 
-    expect(spans.count).to eq(1)
-    span = spans.first
     expect(span.get_tag(Datadog::Ext::Test::TAG_NAME)).to match(/some unnamed test example at .+/)
   end
 
   it 'creates span for deeply nested examples' do
-    spans = []
-    spec = RSpec.describe 'some nested test' do
-      let(:active_span) { Datadog.configuration[:rspec][:tracer].active_span }
-
-      context '1' do
-        context '2' do
-          context '3' do
-            context '4' do
-              context '5' do
-                context '6' do
-                  context '7' do
-                    context '8' do
-                      context '9' do
-                        context '10' do
-                          it 'foo' do
-                            spans << active_span
+    spec = with_new_rspec_environment do
+      RSpec.describe 'some nested test' do
+        context '1' do
+          context '2' do
+            context '3' do
+              context '4' do
+                context '5' do
+                  context '6' do
+                    context '7' do
+                      context '8' do
+                        context '9' do
+                          context '10' do
+                            it 'foo' do; end
                           end
                         end
                       end
@@ -104,21 +92,16 @@
             end
           end
         end
-      end
+      end.tap(&:run)
     end
-    spec.run
 
-    expect(spans.count).to eq(1)
-    span = spans.first
     expect(span.resource).to eq('some nested test 1 2 3 4 5 6 7 8 9 10 foo')
     expect(span.get_tag(Datadog::Ext::Test::TAG_NAME)).to eq('some nested test 1 2 3 4 5 6 7 8 9 10 foo')
     expect(span.get_tag(Datadog::Ext::Test::TAG_SUITE)).to eq(spec.file_path)
   end
 
   context 'catches failures' do
     def expect_failure
-      expect(spans.count).to eq(1)
-      span = spans.first
       expect(span.get_tag(Datadog::Ext::Test::TAG_STATUS)).to eq(Datadog::Ext::Test::Status::FAIL)
       expect(span).to have_error
       expect(span).to have_error_type
@@ -127,72 +110,58 @@ def expect_failure
     end
 
     it 'within let' do
-      spans = []
-      spec = RSpec.describe 'some failed test with let' do
-        let(:active_span) { Datadog.configuration[:rspec][:tracer].active_span }
-        let(:let_failure) { raise 'failure' }
-
-        it 'foo' do
-          spans << active_span
-          let_failure
-        end
+      with_new_rspec_environment do
+        RSpec.describe 'some failed test with let' do
+          let(:let_failure) { raise 'failure' }
+
+          it 'foo' do
+            let_failure
+          end
+        end.run
       end
-      spec.run
 
       expect_failure
     end
 
     it 'within around' do
-      spans = []
-      spec = RSpec.describe 'some failed test with around' do
-        let(:active_span) { Datadog.configuration[:rspec][:tracer].active_span }
-
-        around do |example|
-          example.run
-          raise 'failure'
-        end
+      with_new_rspec_environment do
+        RSpec.describe 'some failed test with around' do
+          around do |example|
+            example.run
+            raise 'failure'
+          end
 
-        it 'foo' do
-          spans << active_span
-        end
+          it 'foo' do; end
+        end.run
       end
-      spec.run
 
       expect_failure
     end
 
     it 'within before' do
-      spans = []
-      spec = RSpec.describe 'some failed test with before' do
-        let(:active_span) { Datadog.configuration[:rspec][:tracer].active_span }
-
-        before do
-          spans << active_span
-          raise 'failure'
-        end
+      with_new_rspec_environment do
+        RSpec.describe 'some failed test with before' do
+          before do
+            raise 'failure'
+          end
 
-        it 'foo' do
-        end
+          it 'foo' do; end
+        end.run
       end
-      spec.run
 
       expect_failure
     end
 
     it 'within after' do
-      spans = []
-      spec = RSpec.describe 'some failed test with before' do
-        let(:active_span) { Datadog.configuration[:rspec][:tracer].active_span }
-
-        after do
-          raise 'failure'
-        end
+      with_new_rspec_environment do
+        RSpec.describe 'some failed test with after' do
+          after do
+            raise 'failure'
+          end
 
-        it 'foo' do
-          spans << active_span
-        end
+          it 'foo' do; end
+        end.run
       end
-      spec.run
 
       expect_failure
     end