Merge branch 'issue_34622' into 'master'

Group milestones API endpoint

Closes #34622

See merge request !12819

7 files changed, 282 insertions, 157 deletions

diff --git a/lib/api/api.rb b/lib/api/api.rb
index 9a983d31ac6..3bdafa3edc1 100644
--- a/lib/api/api.rb
+++ b/lib/api/api.rb
@@ -110,7 +110,8 @@ module API
     mount ::API::Members
     mount ::API::MergeRequestDiffs
     mount ::API::MergeRequests
-    mount ::API::Milestones
+    mount ::API::ProjectMilestones
+    mount ::API::GroupMilestones
     mount ::API::Namespaces
     mount ::API::Notes
     mount ::API::NotificationSettings
diff --git a/lib/api/entities.rb b/lib/api/entities.rb
index c165236105f..5cdc441e8cb 100644
--- a/lib/api/entities.rb
+++ b/lib/api/entities.rb
@@ -301,8 +301,8 @@ module API
 
     class Milestone < Grape::Entity
       expose :id, :iid
-      expose(:project_id) { |entity| entity&.project_id }
-      expose(:group_id) { |entity| entity&.group_id }
+      expose :project_id, if: -> (entity, options) { entity&.project_id }
+      expose :group_id, if: -> (entity, options) { entity&.group_id }
       expose :title, :description
       expose :state, :created_at, :updated_at
       expose :due_date
diff --git a/lib/api/group_milestones.rb b/lib/api/group_milestones.rb
new file mode 100644
index 00000000000..b85eb59dc0a
--- /dev/null
+++ b/lib/api/group_milestones.rb
@@ -0,0 +1,85 @@
+module API
+  class GroupMilestones < Grape::API
+    include MilestoneResponses
+    include PaginationParams
+
+    before do
+      authenticate!
+    end
+
+    params do
+      requires :id, type: String, desc: 'The ID of a group'
+    end
+    resource :groups, requirements: { id: %r{[^/]+} } do
+      desc 'Get a list of group milestones' do
+        success Entities::Milestone
+      end
+      params do
+        use :list_params
+      end
+      get ":id/milestones" do
+        list_milestones_for(user_group)
+      end
+
+      desc 'Get a single group milestone' do
+        success Entities::Milestone
+      end
+      params do
+        requires :milestone_id, type: Integer, desc: 'The ID of a group milestone'
+      end
+      get ":id/milestones/:milestone_id" do
+        authorize! :read_group, user_group
+
+        get_milestone_for(user_group)
+      end
+
+      desc 'Create a new group milestone' do
+        success Entities::Milestone
+      end
+      params do
+        requires :title, type: String, desc: 'The title of the milestone'
+        use :optional_params
+      end
+      post ":id/milestones" do
+        authorize! :admin_milestones, user_group
+
+        create_milestone_for(user_group)
+      end
+
+      desc 'Update an existing group milestone' do
+        success Entities::Milestone
+      end
+      params do
+        use :update_params
+      end
+      put ":id/milestones/:milestone_id" do
+        authorize! :admin_milestones, user_group
+
+        update_milestone_for(user_group)
+      end
+
+      desc 'Get all issues for a single group milestone' do
+        success Entities::IssueBasic
+      end
+      params do
+        requires :milestone_id, type: Integer, desc: 'The ID of a group milestone'
+        use :pagination
+      end
+      get ":id/milestones/:milestone_id/issues" do
+        milestone_issuables_for(user_group, :issue)
+      end
+
+      desc 'Get all merge requests for a single group milestone' do
+        detail 'This feature was introduced in GitLab 9.'
+        success Entities::MergeRequestBasic
+      end
+      params do
+        requires :milestone_id, type: Integer, desc: 'The ID of a group milestone'
+        use :pagination
+      end
+      get ':id/milestones/:milestone_id/merge_requests' do
+        milestone_issuables_for(user_group, :merge_request)
+      end
+    end
+  end
+end
diff --git a/lib/api/helpers.rb b/lib/api/helpers.rb
index 0f4791841d2..57e3e93500f 100644
--- a/lib/api/helpers.rb
+++ b/lib/api/helpers.rb
@@ -25,6 +25,10 @@ module API
       initial_current_user != current_user
     end
 
+    def user_group
+      @group ||= find_group!(params[:id])
+    end
+
     def user_project
       @project ||= find_project!(params[:id])
     end
diff --git a/lib/api/milestone_responses.rb b/lib/api/milestone_responses.rb
new file mode 100644
index 00000000000..ef09d9505d2
--- /dev/null
+++ b/lib/api/milestone_responses.rb
@@ -0,0 +1,98 @@
+module API
+  module MilestoneResponses
+    extend ActiveSupport::Concern
+
+    included do
+      helpers do
+        params :optional_params do
+          optional :description, type: String, desc: 'The description of the milestone'
+          optional :due_date, type: String, desc: 'The due date of the milestone. The ISO 8601 date format (%Y-%m-%d)'
+          optional :start_date, type: String, desc: 'The start date of the milestone. The ISO 8601 date format (%Y-%m-%d)'
+        end
+
+        params :list_params do
+          optional :state, type: String, values: %w[active closed all], default: 'all',
+                           desc: 'Return "active", "closed", or "all" milestones'
+          optional :iids, type: Array[Integer], desc: 'The IIDs of the milestones'
+          optional :search, type: String, desc: 'The search criteria for the title or description of the milestone'
+          use :pagination
+        end
+
+        params :update_params do
+          requires :milestone_id, type: Integer, desc: 'The milestone ID number'
+          optional :title, type: String, desc: 'The title of the milestone'
+          optional :state_event, type: String, values: %w[close activate],
+                                 desc: 'The state event of the milestone '
+          use :optional_params
+          at_least_one_of :title, :description, :due_date, :state_event
+        end
+
+        def list_milestones_for(parent)
+          milestones = parent.milestones
+          milestones = Milestone.filter_by_state(milestones, params[:state])
+          milestones = filter_by_iid(milestones, params[:iids]) if params[:iids].present?
+          milestones = filter_by_search(milestones, params[:search]) if params[:search]
+
+          present paginate(milestones), with: Entities::Milestone
+        end
+
+        def get_milestone_for(parent)
+          milestone = parent.milestones.find(params[:milestone_id])
+          present milestone, with: Entities::Milestone
+        end
+
+        def create_milestone_for(parent)
+          milestone = ::Milestones::CreateService.new(parent, current_user, declared_params).execute
+
+          if milestone.valid?
+            present milestone, with: Entities::Milestone
+          else
+            render_api_error!("Failed to create milestone #{milestone.errors.messages}", 400)
+          end
+        end
+
+        def update_milestone_for(parent)
+          milestone = parent.milestones.find(params.delete(:milestone_id))
+
+          milestone_params = declared_params(include_missing: false)
+          milestone = ::Milestones::UpdateService.new(parent, current_user, milestone_params).execute(milestone)
+
+          if milestone.valid?
+            present milestone, with: Entities::Milestone
+          else
+            render_api_error!("Failed to update milestone #{milestone.errors.messages}", 400)
+          end
+        end
+
+        def milestone_issuables_for(parent, type)
+          milestone = parent.milestones.find(params[:milestone_id])
+
+          finder_klass, entity = get_finder_and_entity(type)
+
+          params = build_finder_params(milestone, parent)
+
+          issuables = finder_klass.new(current_user, params).execute
+          present paginate(issuables), with: entity, current_user: current_user
+        end
+
+        def build_finder_params(milestone, parent)
+          finder_params = { milestone_title: milestone.title, sort: 'label_priority' }
+
+          if parent.is_a?(Group)
+            finder_params.merge(group_id: parent.id)
+          else
+            finder_params.merge(project_id: parent.id)
+          end
+        end
+
+        def get_finder_and_entity(type)
+          if type == :issue
+            [IssuesFinder, Entities::IssueBasic]
+          else
+            [MergeRequestsFinder, Entities::MergeRequestBasic]
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/lib/api/milestones.rb b/lib/api/milestones.rb
deleted file mode 100644
index 3541d3c95fb..00000000000
--- a/lib/api/milestones.rb
+++ /dev/null
@@ -1,154 +0,0 @@
-module API
-  class Milestones < Grape::API
-    include PaginationParams
-
-    before { authenticate! }
-
-    helpers do
-      def filter_milestones_state(milestones, state)
-        case state
-        when 'active' then milestones.active
-        when 'closed' then milestones.closed
-        else milestones
-        end
-      end
-
-      params :optional_params do
-        optional :description, type: String, desc: 'The description of the milestone'
-        optional :due_date, type: String, desc: 'The due date of the milestone. The ISO 8601 date format (%Y-%m-%d)'
-        optional :start_date, type: String, desc: 'The start date of the milestone. The ISO 8601 date format (%Y-%m-%d)'
-      end
-    end
-
-    params do
-      requires :id, type: String, desc: 'The ID of a project'
-    end
-    resource :projects, requirements: { id: %r{[^/]+} } do
-      desc 'Get a list of project milestones' do
-        success Entities::Milestone
-      end
-      params do
-        optional :state, type: String, values: %w[active closed all], default: 'all',
-                         desc: 'Return "active", "closed", or "all" milestones'
-        optional :iids, type: Array[Integer], desc: 'The IIDs of the milestones'
-        optional :search, type: String, desc: 'The search criteria for the title or description of the milestone'
-        use :pagination
-      end
-      get ":id/milestones" do
-        authorize! :read_milestone, user_project
-
-        milestones = user_project.milestones
-        milestones = filter_milestones_state(milestones, params[:state])
-        milestones = filter_by_iid(milestones, params[:iids]) if params[:iids].present?
-        milestones = filter_by_search(milestones, params[:search]) if params[:search]
-
-        present paginate(milestones), with: Entities::Milestone
-      end
-
-      desc 'Get a single project milestone' do
-        success Entities::Milestone
-      end
-      params do
-        requires :milestone_id, type: Integer, desc: 'The ID of a project milestone'
-      end
-      get ":id/milestones/:milestone_id" do
-        authorize! :read_milestone, user_project
-
-        milestone = user_project.milestones.find(params[:milestone_id])
-        present milestone, with: Entities::Milestone
-      end
-
-      desc 'Create a new project milestone' do
-        success Entities::Milestone
-      end
-      params do
-        requires :title, type: String, desc: 'The title of the milestone'
-        use :optional_params
-      end
-      post ":id/milestones" do
-        authorize! :admin_milestone, user_project
-
-        milestone = ::Milestones::CreateService.new(user_project, current_user, declared_params).execute
-
-        if milestone.valid?
-          present milestone, with: Entities::Milestone
-        else
-          render_api_error!("Failed to create milestone #{milestone.errors.messages}", 400)
-        end
-      end
-
-      desc 'Update an existing project milestone' do
-        success Entities::Milestone
-      end
-      params do
-        requires :milestone_id, type: Integer, desc: 'The ID of a project milestone'
-        optional :title, type: String, desc: 'The title of the milestone'
-        optional :state_event, type: String, values: %w[close activate],
-                               desc: 'The state event of the milestone '
-        use :optional_params
-        at_least_one_of :title, :description, :due_date, :state_event
-      end
-      put ":id/milestones/:milestone_id" do
-        authorize! :admin_milestone, user_project
-        milestone = user_project.milestones.find(params.delete(:milestone_id))
-
-        milestone_params = declared_params(include_missing: false)
-        milestone = ::Milestones::UpdateService.new(user_project, current_user, milestone_params).execute(milestone)
-
-        if milestone.valid?
-          present milestone, with: Entities::Milestone
-        else
-          render_api_error!("Failed to update milestone #{milestone.errors.messages}", 400)
-        end
-      end
-
-      desc 'Get all issues for a single project milestone' do
-        success Entities::IssueBasic
-      end
-      params do
-        requires :milestone_id, type: Integer, desc: 'The ID of a project milestone'
-        use :pagination
-      end
-      get ":id/milestones/:milestone_id/issues" do
-        authorize! :read_milestone, user_project
-
-        milestone = user_project.milestones.find(params[:milestone_id])
-
-        finder_params = {
-          project_id: user_project.id,
-          milestone_title: milestone.title,
-          sort: 'label_priority'
-        }
-
-        issues = IssuesFinder.new(current_user, finder_params).execute
-        present paginate(issues), with: Entities::IssueBasic, current_user: current_user, project: user_project
-      end
-
-      desc 'Get all merge requests for a single project milestone' do
-        detail 'This feature was introduced in GitLab 9.'
-        success Entities::MergeRequestBasic
-      end
-      params do
-        requires :milestone_id, type: Integer, desc: 'The ID of a project milestone'
-        use :pagination
-      end
-      get ':id/milestones/:milestone_id/merge_requests' do
-        authorize! :read_milestone, user_project
-
-        milestone = user_project.milestones.find(params[:milestone_id])
-
-        finder_params = {
-          project_id: user_project.id,
-          milestone_title: milestone.title,
-          sort: 'label_priority'
-        }
-
-        merge_requests = MergeRequestsFinder.new(current_user, finder_params).execute
-        present paginate(merge_requests),
-          with: Entities::MergeRequestBasic,
-          current_user: current_user,
-          project: user_project
-      end
-    end
-  end
-end
diff --git a/lib/api/project_milestones.rb b/lib/api/project_milestones.rb
new file mode 100644
index 00000000000..451998c726a
--- /dev/null
+++ b/lib/api/project_milestones.rb
@@ -0,0 +1,91 @@
+module API
+  class ProjectMilestones < Grape::API
+    include PaginationParams
+    include MilestoneResponses
+
+    before do
+      authenticate!
+    end
+
+    params do
+      requires :id, type: String, desc: 'The ID of a project'
+    end
+    resource :projects, requirements: { id: %r{[^/]+} } do
+      desc 'Get a list of project milestones' do
+        success Entities::Milestone
+      end
+      params do
+        use :list_params
+      end
+      get ":id/milestones" do
+        authorize! :read_milestone, user_project
+
+        list_milestones_for(user_project)
+      end
+
+      desc 'Get a single project milestone' do
+        success Entities::Milestone
+      end
+      params do
+        requires :milestone_id, type: Integer, desc: 'The ID of a project milestone'
+      end
+      get ":id/milestones/:milestone_id" do
+        authorize! :read_milestone, user_project
+
+        get_milestone_for(user_project)
+      end
+
+      desc 'Create a new project milestone' do
+        success Entities::Milestone
+      end
+      params do
+        requires :title, type: String, desc: 'The title of the milestone'
+        use :optional_params
+      end
+      post ":id/milestones" do
+        authorize! :admin_milestone, user_project
+
+        create_milestone_for(user_project)
+      end
+
+      desc 'Update an existing project milestone' do
+        success Entities::Milestone
+      end
+      params do
+        use :update_params
+      end
+      put ":id/milestones/:milestone_id" do
+        authorize! :admin_milestone, user_project
+
+        update_milestone_for(user_project)
+      end
+
+      desc 'Get all issues for a single project milestone' do
+        success Entities::IssueBasic
+      end
+      params do
+        requires :milestone_id, type: Integer, desc: 'The ID of a project milestone'
+        use :pagination
+      end
+      get ":id/milestones/:milestone_id/issues" do
+        authorize! :read_milestone, user_project
+
+        milestone_issuables_for(user_project, :issue)
+      end
+
+      desc 'Get all merge requests for a single project milestone' do
+        detail 'This feature was introduced in GitLab 9.'
+        success Entities::MergeRequestBasic
+      end
+      params do
+        requires :milestone_id, type: Integer, desc: 'The ID of a project milestone'
+        use :pagination
+      end
+      get ':id/milestones/:milestone_id/merge_requests' do
+        authorize! :read_milestone, user_project
+
+        milestone_issuables_for(user_project, :merge_request)
+      end
+    end
+  end
+end