Separate feature flag for each analytics feature

- Adding Analytics module to keep track of analytics feature flags.
- Check feature flag in analytics controllers.
- Enable Analytics workspace when at least one analytics feature is
enabled

doc/user/analytics/cycle_analytics.md

 # Cycle Analytics
 
 > - Introduced prior to GitLab 12.2 at the project level.
-> - [Introduced](https://gitlab.com/gitlab-org/gitlab-ee/issues/12077) in [GitLab Premium](https://about.gitlab.com/pricing/) 12.2 at the group level (enabled by feature flag `analytics`).
+> - [Introduced](https://gitlab.com/gitlab-org/gitlab-ee/issues/12077) in [GitLab Premium](https://about.gitlab.com/pricing/) 12.2 at the group level.
+
+NOTE: **Note:**
+As of GitLab 12.3 this feature is enabled by the `cycle_analytics` feature flag.
 
 Cycle Analytics measures the time spent to go from an [idea to production] - also known
 as cycle time - for each of your projects. Cycle Analytics displays the median time for an idea to
@@ -24,9 +27,6 @@ Cycle Analytics is available:
   In the future, multiple groups will be selectable which will effectively make this an
   instance-level feature.
 
-  NOTE: **Note:**
-  Requires the [analytics workspace](index.md) to be enabled.
-
 - At the project level via **Project > Cycle Analytics**.
 
 There are seven stages that are tracked as part of the Cycle Analytics calculations.

doc/user/analytics/index.md

 # Analytics workspace
 
-> [Introduced](https://gitlab.com/gitlab-org/gitlab-ee/issues/12077) in GitLab 12.2 (enabled using `analytics` feature flag).
+> [Introduced](https://gitlab.com/gitlab-org/gitlab-ee/issues/12077) in GitLab 12.2.
 
 The Analytics workspace will make it possible to aggregate analytics across
 GitLab, so that users can view information across multiple projects and groups
 in one place.
 
-To access the centralized analytics workspace:
-
-1. Ensure it's enabled. Requires a GitLab administrator to enable it with the `analytics` feature
-   flag.
-1. Once enabled, click on **Analytics** from the top navigation bar.
+To access the centralized analytics workspace, click on **Analytics** from the top navigation bar.
 
 ## Available analytics
 
 From the centralized analytics workspace, the following analytics are available:
 
-- [Cycle Analytics](cycle_analytics.md).
+- [Cycle Analytics](cycle_analytics.md):
+
+1. Requires a GitLab administrator to enable it with the `cycle_analytics` feature flag.
+1. Once enabled, click on **Analytics** and then **Cycle Analytics** from the top navigation bar.
 
 NOTE: **Note:**
 Project-level Cycle Analytics are still available at a project's **Project > Cycle Analytics**.

ee/app/controllers/analytics/analytics_controller.rb

+# frozen_string_literal: true
+
+class Analytics::AnalyticsController < Analytics::ApplicationController
+  def index
+    if Gitlab::Analytics.productivity_analytics_enabled?
+      redirect_to analytics_productivity_analytics_path
+    elsif Gitlab::Analytics.cycle_analytics_enabled?
+      redirect_to analytics_cycle_analytics_path
+    else
+      render_404
+    end
+  end
+end

ee/app/controllers/analytics/application_controller.rb

@@ -4,4 +4,12 @@ class Analytics::ApplicationController < ApplicationController
   include RoutableActions
 
   layout 'analytics'
+
+  private
+
+  def self.check_feature_flag(flag, *args)
+    before_action(*args) { render_404 unless Feature.enabled?(flag) }
+  end
+
+  private_class_method :check_feature_flag
 end

ee/app/controllers/analytics/cycle_analytics_controller.rb

 # frozen_string_literal: true
 
 class Analytics::CycleAnalyticsController < Analytics::ApplicationController
+  check_feature_flag Gitlab::Analytics::CYCLE_ANALYTICS_FEATURE_FLAG
 end

ee/app/controllers/analytics/productivity_analytics_controller.rb

 # frozen_string_literal: true
 
 class Analytics::ProductivityAnalyticsController < Analytics::ApplicationController
+  check_feature_flag Gitlab::Analytics::PRODUCTIVITY_ANALYTICS_FEATURE_FLAG
+
   before_action :load_group
   before_action :load_project
   before_action :check_feature_availability!

ee/app/helpers/ee/dashboard_helper.rb

@@ -36,7 +36,7 @@ module EE
     override :get_dashboard_nav_links
     def get_dashboard_nav_links
       super.tap do |links|
-        links << :analytics if ::Feature.enabled?(:analytics)
+        links << :analytics if ::Gitlab::Analytics.any_features_enabled?
       end
     end
   end

ee/app/views/layouts/nav/sidebar/_analytics.html.haml

@@ -6,7 +6,7 @@
           = sprite_icon('log', size: 24)
         .sidebar-context-title= _('Analytics')
       %ul.sidebar-top-level-items
-      - if Feature.enabled?(:productivity_analytics)
+        - if Gitlab::Analytics.productivity_analytics_enabled?
           = nav_link(controller: :productivity_analytics) do
             = link_to analytics_productivity_analytics_path, class: 'qa-sidebar-productivity-analytics' do
               .nav-icon-container
@@ -19,7 +19,7 @@
                   %strong.fly-out-top-item-name
                     = _('Productivity Analytics')
 
-      - if Feature.enabled?(:cycle_analytics)
+        - if Gitlab::Analytics.cycle_analytics_enabled?
           = nav_link(controller: :cycle_analytics) do
             = link_to analytics_cycle_analytics_path, class: 'qa-sidebar-cycle-analytics' do
               .nav-icon-container
@@ -31,5 +31,4 @@
                 = link_to analytics_cycle_analytics_path do
                   %strong.fly-out-top-item-name
                     = _('Cycle Analytics')
-
     = render 'shared/sidebar_toggle_button'

ee/changelogs/unreleased/14671-analytics-feature-flags.yml

+---
+title: Eliminating `analytics` feature flag and introduce separate feature flags for Analytics features.
+merge_request: 16102
+author:
+type: changed

ee/config/routes/analytics.rb

 # frozen_string_literal: true
 
 namespace :analytics do
-  constraints(::Constraints::FeatureConstrainer.new(:productivity_analytics)) do
-    root to: redirect('-/analytics/productivity_analytics')
+  root to: 'analytics#index'
 
+  constraints(::Constraints::FeatureConstrainer.new(:productivity_analytics)) do
     resource :productivity_analytics, only: :show
   end
 

ee/lib/gitlab/analytics.rb

+# frozen_string_literal: true
+
+module Gitlab
+  module Analytics
+    # Normally each analytics feature should be guarded with a feature flag.
+    CYCLE_ANALYTICS_FEATURE_FLAG = :cycle_analytics
+    PRODUCTIVITY_ANALYTICS_FEATURE_FLAG = :productivity_analytics
+
+    FEATURE_FLAGS = [
+      CYCLE_ANALYTICS_FEATURE_FLAG,
+      PRODUCTIVITY_ANALYTICS_FEATURE_FLAG
+    ].freeze
+
+    def self.any_features_enabled?
+      FEATURE_FLAGS.any? { |flag| Feature.enabled?(flag) }
+    end
+
+    def self.cycle_analytics_enabled?
+      Feature.enabled?(CYCLE_ANALYTICS_FEATURE_FLAG)
+    end
+
+    def self.productivity_analytics_enabled?
+      Feature.enabled?(PRODUCTIVITY_ANALYTICS_FEATURE_FLAG)
+    end
+  end
+end

ee/spec/controllers/analytics/analytics_controller_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe Analytics::AnalyticsController do
+  include AnalyticsHelpers
+
+  let(:user) { create(:user) }
+
+  before do
+    sign_in(user)
+  end
+
+  describe 'GET index' do
+    describe 'redirects to the first enabled analytics page' do
+      it 'redirects to cycle analytics' do
+        disable_all_analytics_feature_flags
+        stub_feature_flags(Gitlab::Analytics::CYCLE_ANALYTICS_FEATURE_FLAG => true)
+
+        get :index
+
+        expect(response).to redirect_to(analytics_cycle_analytics_path)
+      end
+
+      it 'redirects to productivity analytics' do
+        disable_all_analytics_feature_flags
+        stub_feature_flags(Gitlab::Analytics::PRODUCTIVITY_ANALYTICS_FEATURE_FLAG => true)
+
+        get :index
+
+        expect(response).to redirect_to(analytics_productivity_analytics_path)
+      end
+    end
+
+    it 'renders 404 all the analytics feature flags are disabled' do
+      disable_all_analytics_feature_flags
+
+      get :index
+
+      expect(response).to have_gitlab_http_status(404)
+    end
+  end
+end

ee/spec/controllers/analytics/cycle_analytics_controller_spec.rb

@@ -11,9 +11,19 @@ describe Analytics::CycleAnalyticsController do
 
   describe 'GET show' do
     it 'renders `show` template' do
+      stub_feature_flags(Gitlab::Analytics::CYCLE_ANALYTICS_FEATURE_FLAG => true)
+
       get :show
 
       expect(response).to render_template :show
     end
+
+    it 'renders `404` when feature flag is disabled' do
+      stub_feature_flags(Gitlab::Analytics::CYCLE_ANALYTICS_FEATURE_FLAG => false)
+
+      get :show
+
+      expect(response).to have_gitlab_http_status(404)
+    end
   end
 end

ee/spec/controllers/analytics/productivity_analytics_controller_spec.rb

@@ -35,6 +35,15 @@ describe Analytics::ProductivityAnalyticsController do
 
       expect(response).to render_template :show
     end
+
+    it 'renders `404` when feature flag is disabled' do
+      stub_licensed_features(productivity_analytics: true)
+      stub_feature_flags(Gitlab::Analytics::PRODUCTIVITY_ANALYTICS_FEATURE_FLAG => false)
+
+      get :show
+
+      expect(response).to have_gitlab_http_status(404)
+    end
   end
 
   describe 'GET show.json' do

ee/spec/helpers/ee/dashboard_helper_spec.rb

@@ -3,6 +3,8 @@
 require 'spec_helper'
 
 describe DashboardHelper, type: :helper do
+  include AnalyticsHelpers
+
   let(:user) { build(:user) }
 
   before do
@@ -11,9 +13,9 @@ describe DashboardHelper, type: :helper do
   end
 
   describe '#dashboard_nav_links' do
-    context 'when analytics is enabled' do
+    context 'when at least one analytics feature is enabled' do
       before do
-        stub_feature_flags(analytics: true)
+        enable_only_one_analytics_feature_flag
       end
 
       it 'includes analytics' do
@@ -21,9 +23,9 @@ describe DashboardHelper, type: :helper do
       end
     end
 
-    context 'when analytics is disabled' do
+    context 'when all analytics features are disabled' do
       before do
-        stub_feature_flags(analytics: false)
+        disable_all_analytics_feature_flags
       end
 
       it 'does not include analytics' do

ee/spec/routing/analytics_routing_spec.rb

@@ -6,25 +6,7 @@ describe 'Analytics' do
   include RSpec::Rails::RequestExampleGroup
   include Warden::Test::Helpers
 
-  let(:user) { create(:user) }
-
-  it "redirects to productivity_analytics" do
-    expect(get('/-/analytics')).to redirect_to('/-/analytics/productivity_analytics')
-  end
-
-  context ':analytics feature is disabled' do
-    before do
-      stub_feature_flags(analytics: false)
-    end
-
   it 'redirects to sign_in if user is not authenticated' do
     expect(get('/-/analytics')).to redirect_to('/users/sign_in')
   end
-
-    it 'returns 404 if user is authenticated' do
-      login_as(user)
-
-      expect(get('/-/analytics')).to eq(404)
-    end
-  end
 end

ee/spec/support/helpers/analytics_helpers.rb

+# frozen_string_literal: true
+
+# Helper for analytics related features
+module AnalyticsHelpers
+  def disable_all_analytics_feature_flags
+    Gitlab::Analytics::FEATURE_FLAGS.each do |flag|
+      stub_feature_flags(flag => false)
+    end
+  end
+
+  def enable_only_one_analytics_feature_flag
+    Gitlab::Analytics::FEATURE_FLAGS.each_with_index do |flag, i|
+      stub_feature_flags(flag => i == 0)
+    end
+  end
+end

ee/spec/views/layouts/nav/sidebar/_analytics.html.haml_spec.rb

@@ -3,29 +3,50 @@
 require 'spec_helper'
 
 describe 'layouts/nav/sidebar/_analytics' do
+  include AnalyticsHelpers
+
   it_behaves_like 'has nav sidebar'
 
   context 'top-level items' do
-    before do
+    context 'when feature flags are enabled' do
+      it 'has `Analytics` link' do
+        stub_feature_flags(Gitlab::Analytics::PRODUCTIVITY_ANALYTICS_FEATURE_FLAG => true)
+
         render
-    end
 
-    it 'has `Analytics` link' do
         expect(rendered).to have_content('Analytics')
         expect(rendered).to include(analytics_root_path)
         expect(rendered).to match(/<use xlink:href=".+?icons-.+?#log">/)
       end
 
       it 'has `Productivity Analytics` link' do
+        stub_feature_flags(Gitlab::Analytics::PRODUCTIVITY_ANALYTICS_FEATURE_FLAG => true)
+
+        render
+
         expect(rendered).to have_content('Productivity Analytics')
         expect(rendered).to include(analytics_productivity_analytics_path)
         expect(rendered).to match(/<use xlink:href=".+?icons-.+?#comment">/)
       end
 
       it 'has `Cycle Analytics` link' do
+        stub_feature_flags(Gitlab::Analytics::CYCLE_ANALYTICS_FEATURE_FLAG => true)
+
+        render
+
         expect(rendered).to have_content('Cycle Analytics')
         expect(rendered).to include(analytics_cycle_analytics_path)
         expect(rendered).to match(/<use xlink:href=".+?icons-.+?#repeat">/)
       end
     end
+
+    context 'when feature flags are disabled' do
+      it 'no analytics links are rendered' do
+        disable_all_analytics_feature_flags
+
+        expect(rendered).not_to have_content('Productivity Analytics')
+        expect(rendered).not_to have_content('Cycle Analytics')
+      end
+    end
+  end
 end