Detect Cucumber as a development environment

Steepfile

@@ -652,6 +652,7 @@ target :ddtrace do
   library 'digest'
 
   repo_path 'vendor/rbs'
+  library 'cucumber'
   library 'ffi'
   library 'jruby'
   library 'gem'

lib/datadog/core/environment/execution.rb

@@ -34,7 +34,7 @@ def webmock_enabled?
 
           # Is this process running a test?
           def test?
-            rspec? || minitest?
+            rspec? || minitest? || cucumber?
           end
 
           # Is this process running inside on a Read–eval–print loop?
@@ -66,6 +66,11 @@ def minitest?
                 ::Minitest::Unit.class_variable_get(:@@installed_at_exit))
           end
 
+          # Check if we are running from `bin/cucumber` or `cucumber/rake/task`.
+          def cucumber?
+            defined?(::Cucumber::Cli)
+          end
+
           # If this is a Rails application, use different heuristics to detect
           # whether this is a development environment or not.
           def rails_development?

sig/datadog/core/environment/execution.rbs

@@ -5,6 +5,8 @@ module Datadog
         def self.development?: () -> bool
         def self.webmock_enabled?: () -> bool
 
+        def self.cucumber?: -> bool
+
         private
         def self.test?: () -> bool
         def self.repl?: () -> bool

spec/datadog/core/environment/execution_spec.rb

@@ -39,15 +39,15 @@
         end
       end
 
-      let(:repl_script) do
+      let!(:repl_script) do
+        lib = File.expand_path('lib')
         <<-RUBY
           # Load the working directory version of `ddtrace`
-          lib = File.expand_path('lib', __dir__)
-          $LOAD_PATH.unshift(lib) unless $LOAD_PATH.include?(lib)
+          $LOAD_PATH.unshift("#{lib}") unless $LOAD_PATH.include?("#{lib}")
           require 'datadog/core/environment/execution'
 
           # Print actual value to STDERR, as STDOUT tends to have more noise in REPL sessions.
-          STDERR.print Datadog::Core::Environment::Execution.development?
+          STDERR.print "ACTUAL:\#{Datadog::Core::Environment::Execution.development?}"
         RUBY
       end
 
@@ -71,7 +71,7 @@
             f.close
 
             out, = Open3.capture2e('pry', '-f', '--noprompt', f.path)
-            expect(out).to eq('true')
+            expect(out).to eq('ACTUAL:true')
           end
         end
       end
@@ -149,6 +149,43 @@
           end
         end
       end
+
+      context 'for Cucumber' do
+        before do
+          unless PlatformHelpers.ci? || Gem.loaded_specs['cucumber']
+            skip('cucumber gem not present. In CI, this test is never skipped.')
+          end
+        end
+
+        let(:script) do
+          <<-'RUBY'
+            require 'bundler/inline'
+
+            gemfile(true) do
+              source 'https://rubygems.org'
+              gem 'cucumber', '>= 3'
+            end
+
+            load Gem.bin_path('cucumber', 'cucumber')
+          RUBY
+        end
+
+        it 'returns true' do
+          Dir.mktmpdir do |dir|
+            Dir.chdir(dir) do
+              FileUtils.mkdir_p('features/support')
+
+              # Add our script to `env.rb`, which is always run before any feature is executed.
+              File.write('features/support/env.rb', repl_script)
+
+              _, err = Bundler.with_clean_env do
+                Open3.capture3('ruby', stdin_data: script)
+              end
+              expect(err).to include('ACTUAL:true')
+            end
+          end
+        end
+      end
     end
 
     context 'when webmock has enabled net-http adapter' do

vendor/rbs/cucumber/0/cucumber.rbs

@@ -0,0 +1,4 @@
+module Cucumber
+  module Cli
+  end
+end