Adds the security_reports_mr_widget_prompt experiment for a front end feature

app/experiments/security_reports_mr_widget_prompt_experiment.rb

+# frozen_string_literal: true
+
+class SecurityReportsMrWidgetPromptExperiment < ApplicationExperiment # rubocop:disable Gitlab/NamespacedClass
+  def publish(_result = nil)
+    super
+
+    publish_to_database
+  end
+
+  # This is a purely client side experiment, and since we don't have a nicer
+  # way to define variants yet, we define them here.
+  def candidate_behavior
+  end
+end

config/feature_flags/experiment/security_reports_mr_widget_prompt.yml

+---
+name: security_reports_mr_widget_prompt
+introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/70086
+rollout_issue_url: https://gitlab.com/gitlab-org/gitlab/-/issues/340436
+milestone: '14.3'
+type: experiment
+group: group::adoption
+default_enabled: false

ee/app/controllers/ee/projects/merge_requests_controller.rb

@@ -9,6 +9,7 @@ module EE
         include DescriptionDiffActions
 
         before_action only: [:show] do
+          experiment(:security_reports_mr_widget_prompt, namespace: @project.namespace).publish
           push_frontend_feature_flag(:anonymous_visual_review_feedback)
           push_frontend_feature_flag(:missing_mr_security_scan_types, @project)
         end

spec/experiments/security_reports_mr_widget_prompt_experiment_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe SecurityReportsMrWidgetPromptExperiment do
+  it "defines a control and candidate" do
+    expect(subject.behaviors.keys).to match_array(%w[control candidate])
+  end
+
+  it "publishes to the database" do
+    expect(subject).to receive(:publish_to_database)
+
+    subject.publish
+  end
+end