Send new users to Learn GitLab issues board

An experiment where we'll send new users to the Learn GitLab onboarding
issues board once they are done registering.

app/controllers/registrations/experience_levels_controller.rb

@@ -14,7 +14,13 @@ module Registrations
 
       if current_user.save
         hide_advanced_issues
+        record_experiment_user(:default_to_issues_board)
+
+        if experiment_enabled?(:default_to_issues_board) && learn_gitlab.available?
+          redirect_to namespace_project_board_path(params[:namespace_path], learn_gitlab.project, learn_gitlab.board)
+        else
           redirect_to group_path(params[:namespace_path])
+        end
       else
         render :show
       end

lib/gitlab/experimentation.rb

@@ -68,6 +68,9 @@ module Gitlab
       },
       group_only_trials: {
         tracking_category: 'Growth::Conversion::Experiment::GroupOnlyTrials'
+      },
+      default_to_issues_board: {
+        tracking_category: 'Growth::Conversion::Experiment::DefaultToIssuesBoard'
       }
     }.freeze
 

spec/controllers/registrations/experience_levels_controller_spec.rb

@@ -85,16 +85,49 @@ RSpec.describe Registrations::ExperienceLevelsController do
           end
         end
 
-        context 'when a namespace_path is sent' do
-          it { is_expected.to have_gitlab_http_status(:redirect) }
-          it { is_expected.to redirect_to(group_path(namespace)) }
+        describe 'redirection' do
+          let(:project) { build(:project, namespace: namespace, creator: user, path: 'project-path') }
+          let(:issues_board) { build(:board, id: 123, project: project) }
+
+          before do
+            stub_experiment_for_user(
+              onboarding_issues: true,
+              default_to_issues_board: default_to_issues_board_xp?
+            )
+            allow_next_instance_of(LearnGitlab) do |learn_gitlab|
+              allow(learn_gitlab).to receive(:available?).and_return(learn_gitlab_available?)
+              allow(learn_gitlab).to receive(:project).and_return(project)
+              allow(learn_gitlab).to receive(:board).and_return(issues_board)
+            end
           end
 
-        context 'when no namespace_path is sent' do
+          context 'when namespace_path param is missing' do
             let(:params) { super().merge(namespace_path: nil) }
 
-          it { is_expected.to have_gitlab_http_status(:redirect) }
-          it { is_expected.to redirect_to(root_path) }
+            where(
+              default_to_issues_board_xp?: [true, false],
+              learn_gitlab_available?: [true, false]
+            )
+
+            with_them do
+              it { is_expected.to redirect_to('/') }
+            end
+          end
+
+          context 'when we have a namespace_path param' do
+            using RSpec::Parameterized::TableSyntax
+
+            where(:default_to_issues_board_xp?, :learn_gitlab_available?, :path) do
+              true  | true  | '/group-path/project-path/-/boards/123'
+              true  | false | '/group-path'
+              false | true  | '/group-path'
+              false | false | '/group-path'
+            end
+
+            with_them do
+              it { is_expected.to redirect_to(path) }
+            end
+          end
         end
 
         describe 'applying the chosen level' do