Make upcoming milestone work across projects

CHANGELOG

@@ -15,6 +15,7 @@ v 8.8.0 (unreleased)
   - Make build status canceled if any of the jobs was canceled and none failed
   - Upgrade Sidekiq to 4.1.2
   - Added /health_check endpoint for checking service status
+  - Make 'upcoming' filter for milestones work better across projects
   - Sanitize repo paths in new project error message
   - Bump mail_room to 0.7.0 to fix stuck IDLE connections
   - Remove future dates from contribution calendar graph.

app/finders/issuable_finder.rb

@@ -252,8 +252,8 @@ class IssuableFinder
       if filter_by_no_milestone?
         items = items.where(milestone_id: [-1, nil])
       elsif filter_by_upcoming_milestone?
-        upcoming = Milestone.where(project_id: projects).upcoming
-        items = items.joins(:milestone).where(milestones: { title: upcoming.try(:title) })
+        upcoming_ids = Milestone.upcoming_ids_by_projects(projects)
+        items = items.joins(:milestone).where(milestone_id: upcoming_ids)
       else
         items = items.joins(:milestone).where(milestones: { title: params[:milestone_title] })
 

app/models/milestone.rb

@@ -67,8 +67,18 @@ class Milestone < ActiveRecord::Base
     @link_reference_pattern ||= super("milestones", /(?<milestone>\d+)/)
   end
 
-  def self.upcoming
-    self.where('due_date > ?', Time.now).reorder(due_date: :asc).first
+  def self.upcoming_ids_by_projects(projects)
+    rel = unscoped.of_projects(projects).active.where('due_date > ?', Time.now)
+
+    if Gitlab::Database.postgresql?
+      rel.order(:project_id, :due_date).pluck('DISTINCT ON (project_id) id')
+    else
+      rel.
+        group(:project_id).
+        having('due_date = MIN(due_date)').
+        pluck(:id, :project_id, :due_date).
+        map(&:first)
+    end
   end
 
   def to_reference(from_project = nil)

spec/finders/issues_finder_spec.rb

@@ -66,6 +66,40 @@ describe IssuesFinder do
         end
       end
 
+      context 'filtering by upcoming milestone' do
+        let(:params) { { milestone_title: Milestone::Upcoming.name } }
+
+        let(:project_no_upcoming_milestones) { create(:empty_project, :public) }
+        let(:project_next_1_1) { create(:empty_project, :public) }
+        let(:project_next_8_8) { create(:empty_project, :public) }
+
+        let(:yesterday) { Date.today - 1.day }
+        let(:tomorrow) { Date.today + 1.day }
+        let(:two_days_from_now) { Date.today + 2.days }
+        let(:ten_days_from_now) { Date.today + 10.days }
+
+        let(:milestones) do
+          [
+            create(:milestone, :closed, project: project_no_upcoming_milestones),
+            create(:milestone, project: project_next_1_1, title: '1.1', due_date: two_days_from_now),
+            create(:milestone, project: project_next_1_1, title: '8.8', due_date: ten_days_from_now),
+            create(:milestone, project: project_next_8_8, title: '1.1', due_date: yesterday),
+            create(:milestone, project: project_next_8_8, title: '8.8', due_date: tomorrow)
+          ]
+        end
+
+        before do
+          milestones.each do |milestone|
+            create(:issue, project: milestone.project, milestone: milestone, author: user, assignee: user)
+          end
+        end
+
+        it 'returns issues in the upcoming milestone for each project' do
+          expect(issues.map { |issue| issue.milestone.title }).to contain_exactly('1.1', '8.8')
+          expect(issues.map { |issue| issue.milestone.due_date }).to contain_exactly(tomorrow, two_days_from_now)
+        end
+      end
+
       context 'filtering by label' do
         let(:params) { { label_name: label.title } }
 

spec/models/milestone_spec.rb

@@ -204,4 +204,35 @@ describe Milestone, models: true do
         to eq([milestone])
     end
   end
+
+  describe '.upcoming_ids_by_projects' do
+    let(:project_1) { create(:empty_project) }
+    let(:project_2) { create(:empty_project) }
+    let(:project_3) { create(:empty_project) }
+    let(:projects) { [project_1, project_2, project_3] }
+
+    let!(:past_milestone_project_1) { create(:milestone, project: project_1, due_date: Time.now - 1.day) }
+    let!(:current_milestone_project_1) { create(:milestone, project: project_1, due_date: Time.now + 1.day) }
+    let!(:future_milestone_project_1) { create(:milestone, project: project_1, due_date: Time.now + 2.days) }
+
+    let!(:past_milestone_project_2) { create(:milestone, project: project_2, due_date: Time.now - 1.day) }
+    let!(:closed_milestone_project_2) { create(:milestone, :closed, project: project_2, due_date: Time.now + 1.day) }
+    let!(:current_milestone_project_2) { create(:milestone, project: project_2, due_date: Time.now + 2.days) }
+
+    let!(:past_milestone_project_3) { create(:milestone, project: project_3, due_date: Time.now - 1.day) }
+
+    let(:milestone_ids) { Milestone.upcoming_ids_by_projects(projects) }
+
+    it 'returns the next upcoming open milestone ID for each project' do
+      expect(milestone_ids).to contain_exactly(current_milestone_project_1.id, current_milestone_project_2.id)
+    end
+
+    context 'when the projects have no open upcoming milestones' do
+      let(:projects) { [project_3] }
+
+      it 'returns no results' do
+        expect(milestone_ids).to be_empty
+      end
+    end
+  end
 end