Refactor milestone related specs for performance

Refactor to use let_it_be and build wherever suitable
to improve test performance.

spec/finders/milestones_finder_spec.rb

@@ -3,14 +3,16 @@
 require 'spec_helper'
 
 RSpec.describe MilestonesFinder do
-  let(:now) { Time.now }
-  let(:group) { create(:group) }
-  let(:project_1) { create(:project, namespace: group) }
-  let(:project_2) { create(:project, namespace: group) }
-  let!(:milestone_1) { create(:milestone, group: group, title: 'one test', start_date: now - 1.day, due_date: now) }
-  let!(:milestone_2) { create(:milestone, group: group, start_date: now + 1.day, due_date: now + 2.days) }
-  let!(:milestone_3) { create(:milestone, project: project_1, state: 'active', start_date: now + 2.days, due_date: now + 3.days) }
-  let!(:milestone_4) { create(:milestone, project: project_2, state: 'active', start_date: now + 4.days, due_date: now + 5.days) }
+  let_it_be(:now) { Time.now }
+  let_it_be(:group) { create(:group) }
+  let_it_be(:project_1) { create(:project, namespace: group) }
+  let_it_be(:project_2) { create(:project, namespace: group) }
+
+  context 'without filters' do
+    let_it_be(:milestone_1) { create(:milestone, group: group, title: 'one test', start_date: now - 1.day, due_date: now) }
+    let_it_be(:milestone_2) { create(:milestone, group: group, start_date: now + 1.day, due_date: now + 2.days) }
+    let_it_be(:milestone_3) { create(:milestone, project: project_1, state: 'active', start_date: now + 2.days, due_date: now + 3.days) }
+    let_it_be(:milestone_4) { create(:milestone, project: project_2, state: 'active', start_date: now + 4.days, due_date: now + 5.days) }
 
     it 'returns milestones for projects' do
       result = described_class.new(project_ids: [project_1.id, project_2.id], state: 'all').execute
@@ -42,7 +44,21 @@ RSpec.describe MilestonesFinder do
       end
     end
 
+    describe '#find_by' do
+      it 'finds a single milestone' do
+        finder = described_class.new(project_ids: [project_1.id], state: 'all')
+
+        expect(finder.find_by(iid: milestone_3.iid)).to eq(milestone_3)
+      end
+    end
+  end
+
   context 'with filters' do
+    let_it_be(:milestone_1) { create(:milestone, group: group, state: 'closed', title: 'one test', start_date: now - 1.day, due_date: now) }
+    let_it_be(:milestone_2) { create(:milestone, group: group, start_date: now + 1.day, due_date: now + 2.days) }
+    let_it_be(:milestone_3) { create(:milestone, project: project_1, state: 'closed', start_date: now + 2.days, due_date: now + 3.days) }
+    let_it_be(:milestone_4) { create(:milestone, project: project_2, state: 'active', start_date: now + 4.days, due_date: now + 5.days) }
+
     let(:params) do
       {
         project_ids: [project_1.id, project_2.id],
@@ -51,11 +67,6 @@ RSpec.describe MilestonesFinder do
       }
     end
 
-    before do
-      milestone_1.close
-      milestone_3.close
-    end
-
     it 'filters by id' do
       params[:ids] = [milestone_1.id, milestone_2.id]
 
@@ -118,12 +129,4 @@ RSpec.describe MilestonesFinder do
       end
     end
   end
-
-  describe '#find_by' do
-    it 'finds a single milestone' do
-      finder = described_class.new(project_ids: [project_1.id], state: 'all')
-
-      expect(finder.find_by(iid: milestone_3.iid)).to eq(milestone_3)
-    end
-  end
 end

spec/models/milestone_spec.rb

@@ -3,10 +3,9 @@
 require 'spec_helper'
 
 RSpec.describe Milestone do
-  let(:user) { create(:user) }
-  let(:issue) { create(:issue, project: project) }
-  let(:milestone) { create(:milestone, project: project) }
-  let(:project) { create(:project, :public) }
+  let_it_be(:user) { create(:user) }
+  let_it_be(:project) { create(:project, :public) }
+  let_it_be(:issue) { create(:issue, project: project) }
 
   it_behaves_like 'a timebox', :milestone do
     describe "#uniqueness_of_title" do
@@ -92,6 +91,8 @@ RSpec.describe Milestone do
   end
 
   describe '.predefined_id?' do
+    let_it_be(:milestone) { create(:milestone, project: project) }
+
     it 'returns true for a predefined Milestone ID' do
       expect(Milestone.predefined_id?(described_class::Upcoming.id)).to be true
     end
@@ -129,6 +130,8 @@ RSpec.describe Milestone do
   end
 
   describe "#percent_complete" do
+    let(:milestone) { create(:milestone, project: project) }
+
     it "does not count open issues" do
       milestone.issues << issue
       expect(milestone.percent_complete).to eq(0)
@@ -146,6 +149,8 @@ RSpec.describe Milestone do
   end
 
   describe '#expired?' do
+    let_it_be(:milestone) { build(:milestone, project: project) }
+
     context "expired" do
       before do
         allow(milestone).to receive(:due_date).and_return(Date.today.prev_year)
@@ -180,10 +185,14 @@ RSpec.describe Milestone do
   end
 
   describe '#can_be_closed?' do
+    let_it_be(:milestone) { build(:milestone, project: project) }
+
     it { expect(milestone.can_be_closed?).to be_truthy }
   end
 
   describe '#can_be_closed?' do
+    let_it_be(:milestone) { build(:milestone, project: project) }
+
     before do
       milestone = create :milestone, project: project
       create :closed_issue, milestone: milestone, project: project
@@ -335,10 +344,10 @@ RSpec.describe Milestone do
   it_behaves_like '#for_projects_and_groups'
 
   describe '.upcoming_ids' do
-    let(:group_1) { create(:group) }
-    let(:group_2) { create(:group) }
-    let(:group_3) { create(:group) }
-    let(:groups) { [group_1, group_2, group_3] }
+    let_it_be(:group_1) { create(:group) }
+    let_it_be(:group_2) { create(:group) }
+    let_it_be(:group_3) { create(:group) }
+    let_it_be(:groups) { [group_1, group_2, group_3] }
 
     let!(:past_milestone_group_1) { create(:milestone, group: group_1, due_date: Time.current - 1.day) }
     let!(:current_milestone_group_1) { create(:milestone, group: group_1, due_date: Time.current + 1.day) }
@@ -350,10 +359,10 @@ RSpec.describe Milestone do
 
     let!(:past_milestone_group_3) { create(:milestone, group: group_3, due_date: Time.current - 1.day) }
 
-    let(:project_1) { create(:project) }
-    let(:project_2) { create(:project) }
-    let(:project_3) { create(:project) }
-    let(:projects) { [project_1, project_2, project_3] }
+    let_it_be(:project_1) { create(:project) }
+    let_it_be(:project_2) { create(:project) }
+    let_it_be(:project_3) { create(:project) }
+    let_it_be(:projects) { [project_1, project_2, project_3] }
 
     let!(:past_milestone_project_1) { create(:milestone, project: project_1, due_date: Time.current - 1.day) }
     let!(:current_milestone_project_1) { create(:milestone, project: project_1, due_date: Time.current + 1.day) }