New RecaptchaExperimentHelper modules

RecaptchaExperimentHelper contains helper methods
to assist in the controller and view layers.

app/helpers/recaptcha_experiment_helper.rb

+# frozen_string_literal: true
+
+module RecaptchaExperimentHelper
+  def show_recaptcha_sign_up?
+    !!Gitlab::Recaptcha.enabled?
+  end
+end
+
+RecaptchaExperimentHelper.prepend(EE::RecaptchaExperimentHelper)

ee/app/helpers/ee/recaptcha_experiment_helper.rb

+# frozen_string_literal: true
+
+module EE
+  module RecaptchaExperimentHelper
+    include FlipperSessionHelper
+    extend ::Gitlab::Utils::Override
+
+    EXPERIMENT_GROWTH_RECAPTCHA_FEATURE_NAME = :experiment_growth_recaptcha
+
+    override :show_recaptcha_sign_up?
+    def show_recaptcha_sign_up?
+      super && experiment_enabled_for_session?
+    end
+
+    private
+
+    def experiment_enabled_for_session?
+      # If EXPERIMENT_GROWTH_RECAPTCHA_FEATURE_NAME is not set, we should show
+      # reCAPTCHA on the sign_up page
+      return true unless recaptcha_sign_up_experiment_set?
+
+      ::Feature.enabled?(EXPERIMENT_GROWTH_RECAPTCHA_FEATURE_NAME, flipper_session)
+    end
+
+    def recaptcha_sign_up_experiment_set?
+      ::Feature.persisted?(recaptcha_sign_up_experiment_feature)
+    end
+
+    def recaptcha_sign_up_experiment_feature
+      ::Feature.get(EXPERIMENT_GROWTH_RECAPTCHA_FEATURE_NAME)
+    end
+  end
+end

ee/spec/helpers/ee/recaptcha_experiment_helper_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe RecaptchaExperimentHelper, type: :helper do
+  using RSpec::Parameterized::TableSyntax
+
+  describe '.show_recaptcha_sign_up?' do
+    context 'when reCAPTCHA is disabled' do
+      it 'returns false' do
+        stub_application_setting(recaptcha_enabled: false)
+
+        expect(helper.show_recaptcha_sign_up?).to be(false)
+      end
+    end
+
+    context 'when reCAPTCHA is enabled' do
+      before do
+        stub_application_setting(recaptcha_enabled: true)
+      end
+
+      context 'and experiment_growth_recaptcha has not been set' do
+        it 'returns true' do
+          expect(helper.show_recaptcha_sign_up?).to be(true)
+        end
+      end
+
+      context 'and experiment_growth_recaptcha has been set' do
+        let(:feature_name) { described_class::EXPERIMENT_GROWTH_RECAPTCHA_FEATURE_NAME }
+
+        before(:all) do
+          # We need to create a '50%' of actors feature flag before _any_ test
+          # runs and need to continue to use the same feature throughout the
+          # test duration.
+          fifty_percent = ::Feature.flipper.actors(50)
+          ::Feature.flipper[described_class::EXPERIMENT_GROWTH_RECAPTCHA_FEATURE_NAME].enable(fifty_percent)
+        end
+
+        after(:all) do
+          Feature.flipper.remove(described_class::EXPERIMENT_GROWTH_RECAPTCHA_FEATURE_NAME)
+        end
+
+        where(:flipper_session_id, :expected_result) do
+          '00687625-667c-480c-ae2a-9bf861ddd909' | true
+          'b8b78156-f7b8-4bf4-b906-06a899b84ea3' | false
+          'e622a262-6e48-41ba-b19f-2d91c24f17a3' | true
+          'd2c0aae1-bc08-4000-bbb2-0dd2802f67e2' | false
+        end
+
+        with_them do
+          it "returns expected_result" do
+            allow(Feature).to receive(:enabled?).and_call_original # Allow Feature to _really_ work.
+            allow(helper).to receive(:flipper_session).and_return(FlipperSession.new(flipper_session_id))
+
+            expect(helper.show_recaptcha_sign_up?).to eq(expected_result)
+          end
+        end
+      end
+    end
+  end
+end

spec/helpers/recaptcha_experiment_helper_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe RecaptchaExperimentHelper, type: :helper do
+  describe '.show_recaptcha_sign_up?' do
+    context 'when reCAPTCHA is disabled' do
+      it 'returns false' do
+        stub_application_setting(recaptcha_enabled: false)
+
+        expect(helper.show_recaptcha_sign_up?).to be(false)
+      end
+    end
+
+    context 'when reCAPTCHA is enabled' do
+      it 'returns true' do
+        stub_application_setting(recaptcha_enabled: true)
+
+        expect(helper.show_recaptcha_sign_up?).to be(true)
+      end
+    end
+  end
+end