Native group milestones

19 files changed, 466 insertions, 51 deletions

diff --git a/spec/controllers/groups/milestones_controller_spec.rb b/spec/controllers/groups/milestones_controller_spec.rb
index c6e5fb61cf9..aad67dd0164 100644
--- a/spec/controllers/groups/milestones_controller_spec.rb
+++ b/spec/controllers/groups/milestones_controller_spec.rb
@@ -2,8 +2,8 @@ require 'spec_helper'
 
 describe Groups::MilestonesController do
   let(:group) { create(:group) }
-  let(:project) { create(:empty_project, group: group) }
-  let(:project2) { create(:empty_project, group: group) }
+  let!(:project) { create(:empty_project, group: group) }
+  let!(:project2) { create(:empty_project, group: group) }
   let(:user)    { create(:user) }
   let(:title) { '肯定不是中文的问题' }
   let(:milestone) do
@@ -17,24 +17,67 @@ describe Groups::MilestonesController do
   end
   let(:milestone_path) { group_milestone_path(group, milestone.safe_title, title: milestone.title) }
 
+  let(:milestone_params) do
+    {
+      title: title,
+      start_date: Date.today,
+      due_date: 1.month.from_now.to_date
+    }
+  end
+
   before do
     sign_in(user)
     group.add_owner(user)
     project.team << [user, :master]
   end
 
-  describe "#index" do
+  describe '#index' do
     it 'shows group milestones page' do
       get :index, group_id: group.to_param
 
       expect(response).to have_http_status(200)
     end
 
-    it 'shows group milestones JSON' do
-      get :index, group_id: group.to_param, format: :json
+    context 'as JSON' do
+      let!(:milestone) { create(:milestone, group: group, title: 'group milestone') }
+      let!(:legacy_milestone1) { create(:milestone, project: project, title: 'legacy') }
+      let!(:legacy_milestone2) { create(:milestone, project: project2, title: 'legacy') }
 
-      expect(response).to have_http_status(200)
-      expect(response.content_type).to eq 'application/json'
+      it 'lists legacy group milestones and group milestones' do
+        get :index, group_id: group.to_param, format: :json
+
+        milestones = JSON.parse(response.body)
+
+        expect(milestones.count).to eq(2)
+        expect(milestones.first["title"]).to eq("group milestone")
+        expect(milestones.second["title"]).to eq("legacy")
+        expect(response).to have_http_status(200)
+        expect(response.content_type).to eq 'application/json'
+      end
+    end
+  end
+
+  describe '#show' do
+    let(:milestone1) { create(:milestone, project: project, title: 'legacy') }
+    let(:milestone2) { create(:milestone, project: project, title: 'legacy') }
+    let(:group_milestone) { create(:milestone, group: group) }
+
+    context 'when there is a title parameter' do
+      it 'searchs for a legacy group milestone' do
+        expect(GlobalMilestone).to receive(:build)
+        expect(Milestone).not_to receive(:find_by_iid)
+
+        get :show, group_id: group.to_param, id: title, title: milestone1.safe_title
+      end
+    end
+
+    context 'when there is not a title parameter' do
+      it 'searchs for a group milestone' do
+        expect(GlobalMilestone).not_to receive(:build)
+        expect(Milestone).to receive(:find_by_iid)
+
+        get :show, group_id: group.to_param, id: group_milestone.id
+      end
     end
   end
 
@@ -44,16 +87,57 @@ describe Groups::MilestonesController do
     it "creates group milestone with Chinese title" do
       post :create,
            group_id: group.to_param,
-           milestone: { project_ids: [project.id, project2.id], title: title }
+           milestone: milestone_params
 
-      expect(response).to redirect_to(group_milestone_path(group, title.to_slug.to_s, title: title))
-      expect(Milestone.where(title: title).count).to eq(2)
+      milestone = Milestone.find_by_title(title)
+
+      expect(response).to redirect_to(group_milestone_path(group, milestone.iid))
+      expect(milestone.group_id).to eq(group.id)
+      expect(milestone.due_date).to eq(milestone_params[:due_date])
+      expect(milestone.start_date).to eq(milestone_params[:start_date])
+    end
+  end
+
+  describe "#update" do
+    let(:milestone) { create(:milestone, group: group) }
+
+    it "updates group milestone" do
+      milestone_params[:title] = "title changed"
+
+      put :update,
+           id: milestone.iid,
+           group_id: group.to_param,
+           milestone: milestone_params
+
+      milestone.reload
+      expect(response).to redirect_to(group_milestone_path(group, milestone.iid))
+      expect(milestone.title).to eq("title changed")
     end
 
-    it "redirects to new when there are no project ids" do
-      post :create, group_id: group.to_param, milestone: { title: title, project_ids: [""] }
-      expect(response).to render_template :new
-      expect(assigns(:milestone).errors).not_to be_nil
+    context "legacy group milestones" do
+      let!(:milestone1) { create(:milestone, project: project, title: 'legacy milestone', description: "old description") }
+      let!(:milestone2) { create(:milestone, project: project2, title: 'legacy milestone', description: "old description") }
+
+      it "updates only group milestones state" do
+        milestone_params[:title] = "title changed"
+        milestone_params[:description] = "description changed"
+        milestone_params[:state_event] = "close"
+
+        put :update,
+             id: milestone1.title.to_slug.to_s,
+             group_id: group.to_param,
+             milestone: milestone_params,
+             title: milestone1.title
+
+        expect(response).to redirect_to(group_milestone_path(group, milestone1.safe_title, title: milestone1.title))
+
+        [milestone1, milestone2].each do |milestone|
+          milestone.reload
+          expect(milestone.title).to eq("legacy milestone")
+          expect(milestone.description).to eq("old description")
+          expect(milestone.state).to eq("closed")
+        end
+      end
     end
   end
 
@@ -156,7 +240,7 @@ describe Groups::MilestonesController do
       it 'does not 404' do
         post :create,
              group_id: group.to_param,
-             milestone: { project_ids: [project.id, project2.id], title: title }
+             milestone: { title: title }
 
         expect(response).not_to have_http_status(404)
       end
@@ -164,7 +248,7 @@ describe Groups::MilestonesController do
       it 'does not redirect to the correct casing' do
         post :create,
              group_id: group.to_param,
-             milestone: { project_ids: [project.id, project2.id], title: title }
+             milestone: { title: title }
 
         expect(response).not_to have_http_status(301)
       end
@@ -176,7 +260,7 @@ describe Groups::MilestonesController do
       it 'returns not found' do
         post :create,
              group_id: redirect_route.path,
-             milestone: { project_ids: [project.id, project2.id], title: title }
+             milestone: { title: title }
 
         expect(response).to have_http_status(404)
       end
diff --git a/spec/controllers/projects/milestones_controller_spec.rb b/spec/controllers/projects/milestones_controller_spec.rb
index 84a61b2784e..bb5a340cd96 100644
--- a/spec/controllers/projects/milestones_controller_spec.rb
+++ b/spec/controllers/projects/milestones_controller_spec.rb
@@ -31,6 +31,40 @@ describe Projects::MilestonesController do
     end
   end
 
+  describe "#index" do
+    context "as html" do
+      before do
+        get :index, namespace_id: project.namespace.id, project_id: project.id
+      end
+
+      it "queries only projects milestones" do
+        milestones = assigns(:milestones)
+
+        expect(milestones.count).to eq(1)
+        expect(milestones.where(project_id: nil)).to be_empty
+      end
+    end
+
+    context "as json" do
+      let!(:group) { create(:group, :public) }
+      let!(:group_milestone) { create(:milestone, group: group) }
+      let!(:group_member) { create(:group_member, group: group, user: user) }
+
+      before do
+        project.update(namespace: group)
+        get :index, namespace_id: project.namespace.id, project_id: project.id, format: :json
+      end
+
+      it "queries projects milestones and groups milestones" do
+        milestones = assigns(:milestones)
+
+        expect(milestones.count).to eq(2)
+        expect(milestones.where(project_id: nil).first).to eq(group_milestone)
+        expect(milestones.where(group_id: nil).first).to eq(milestone)
+      end
+    end
+  end
+
   describe "#destroy" do
     it "removes milestone" do
       expect(issue.milestone_id).to eq(milestone.id)
diff --git a/spec/factories/milestones.rb b/spec/factories/milestones.rb
index 841ab3c73b8..113665ff11b 100644
--- a/spec/factories/milestones.rb
+++ b/spec/factories/milestones.rb
@@ -1,7 +1,13 @@
 FactoryGirl.define do
   factory :milestone do
     title
-    project factory: :empty_project
+
+    transient do
+      project nil
+      group nil
+      project_id nil
+      group_id nil
+    end
 
     trait :active do
       state "active"
@@ -11,6 +17,20 @@ FactoryGirl.define do
       state "closed"
     end
 
+    after(:build) do |milestone, evaluator|
+      if evaluator.group
+        milestone.group = evaluator.group
+      elsif evaluator.group_id
+        milestone.group_id = evaluator.group_id
+      elsif evaluator.project
+        milestone.project = evaluator.project
+      elsif evaluator.project_id
+        milestone.project_id = evaluator.project_id
+      else
+        milestone.project = create(:empty_project)
+      end
+    end
+
     factory :active_milestone, traits: [:active]
     factory :closed_milestone, traits: [:closed]
   end
diff --git a/spec/features/groups/milestone_spec.rb b/spec/features/groups/milestone_spec.rb
index 330310eae6b..9b6eb946f4b 100644
--- a/spec/features/groups/milestone_spec.rb
+++ b/spec/features/groups/milestone_spec.rb
@@ -33,4 +33,32 @@ feature 'Group milestones', :feature, :js do
       expect(find('.start_date')).to have_content(Date.today.at_beginning_of_month.strftime('%b %-d, %Y'))
     end
   end
+
+  context 'milestones list' do
+    let!(:other_project) { create(:project_empty_repo, group: group) }
+
+    let!(:active_group_milestone) { create(:milestone, group: group, state: 'active') }
+    let!(:active_project_milestone1) { create(:milestone, project: project, state: 'active', title: 'v1.0') }
+    let!(:active_project_milestone2) { create(:milestone, project: other_project, state: 'active', title: 'v1.0') }
+    let!(:closed_group_milestone) { create(:milestone, group: group, state: 'closed') }
+    let!(:closed_project_milestone1) { create(:milestone, project: project, state: 'closed', title: 'v2.0') }
+    let!(:closed_project_milestone2) { create(:milestone, project: other_project, state: 'closed', title: 'v2.0') }
+
+    before do
+      visit group_milestones_path(group)
+    end
+
+    it 'counts milestones correctly' do
+      expect(find('.top-area .active .badge').text).to eq("2")
+      expect(find('.top-area .closed .badge').text).to eq("2")
+      expect(find('.top-area .all .badge').text).to eq("4")
+    end
+
+    it 'lists legacy group milestones and group milestones' do
+      legacy_milestone = GroupMilestone.build_collection(group, group.projects, { state: 'active' }).first
+
+      expect(page).to have_selector("#milestone_#{active_group_milestone.id}", count: 1)
+      expect(page).to have_selector("#milestone_#{legacy_milestone.milestones.first.id}", count: 1)
+    end
+  end
 end
diff --git a/spec/features/milestone_spec.rb b/spec/features/milestone_spec.rb
index 880c53343bc..2afdd0d321c 100644
--- a/spec/features/milestone_spec.rb
+++ b/spec/features/milestone_spec.rb
@@ -1,10 +1,12 @@
 require 'rails_helper'
 
 feature 'Milestone', feature: true do
-  let(:project) { create(:empty_project, :public) }
+  let(:group) { create(:group, :public) }
+  let(:project) { create(:empty_project, :public, namespace: group) }
   let(:user)   { create(:user) }
 
   before do
+    create(:group_member, group: group, user: user)
     project.team << [user, :master]
     gitlab_sign_in(user)
   end
@@ -37,8 +39,8 @@ feature 'Milestone', feature: true do
     end
   end
 
-  feature 'Open a milestone with an existing title' do
-    scenario 'displays validation message' do
+  feature 'Open a project milestone with an existing title' do
+    scenario 'displays validation message when there is a project milestone with same title' do
       milestone = create(:milestone, project: project, title: 8.7)
 
       visit new_project_milestone_path(project)
@@ -47,7 +49,20 @@ feature 'Milestone', feature: true do
       end
       find('input[name="commit"]').click
 
-      expect(find('.alert-danger')).to have_content('Title has already been taken')
+      expect(find('.alert-danger')).to have_content('already being used for another group or project milestone.')
+    end
+
+    scenario 'displays validation message when there is a group milestone with same title' do
+      milestone = create(:milestone, project_id: nil, group: project.group, title: 8.7)
+
+      visit new_group_milestone_path(project.group)
+
+      page.within '.milestone-form' do
+        fill_in "milestone_title", with: milestone.title
+      end
+      find('input[name="commit"]').click
+
+      expect(find('.alert-danger')).to have_content('already being used for another group or project milestone.')
     end
   end
 end
diff --git a/spec/finders/issues_finder_spec.rb b/spec/finders/issues_finder_spec.rb
index 4a52f0d5c58..bef4fd44331 100644
--- a/spec/finders/issues_finder_spec.rb
+++ b/spec/finders/issues_finder_spec.rb
@@ -59,6 +59,23 @@ describe IssuesFinder do
         end
       end
 
+      context 'filtering by group milestone' do
+        let!(:group) { create(:group, :public) }
+        let(:group_milestone) { create(:milestone, group: group) }
+        let!(:group_member) { create(:group_member, group: group, user: user) }
+        let(:params) { { milestone_title: group_milestone.title } }
+
+        before do
+          project2.update(namespace: group)
+          issue2.update(milestone: group_milestone)
+          issue3.update(milestone: group_milestone)
+        end
+
+        it 'returns issues assigned to that group milestone' do
+          expect(issues).to contain_exactly(issue2, issue3)
+        end
+      end
+
       context 'filtering by no milestone' do
         let(:params) { { milestone_title: Milestone::None.title } }
 
diff --git a/spec/finders/merge_requests_finder_spec.rb b/spec/finders/merge_requests_finder_spec.rb
index 5eb26de6c92..b46218bf72e 100644
--- a/spec/finders/merge_requests_finder_spec.rb
+++ b/spec/finders/merge_requests_finder_spec.rb
@@ -47,6 +47,25 @@ describe MergeRequestsFinder do
       expect(merge_requests).to contain_exactly(merge_request1)
     end
 
+    context 'filtering by group milestone' do
+      let!(:group) { create(:group, :public) }
+      let(:group_milestone) { create(:milestone, group: group) }
+      let!(:group_member) { create(:group_member, group: group, user: user) }
+      let(:params) { { milestone_title: group_milestone.title } }
+
+      before do
+        project2.update(namespace: group)
+        merge_request2.update(milestone: group_milestone)
+        merge_request3.update(milestone: group_milestone)
+      end
+
+      it 'returns issues assigned to that group milestone' do
+        merge_requests = described_class.new(user, params).execute
+
+        expect(merge_requests).to contain_exactly(merge_request2, merge_request3)
+      end
+    end
+
     context 'with created_after and created_before params' do
       let(:project4) { create(:empty_project, forked_from_project: project1) }
 
diff --git a/spec/finders/milestones_finder_spec.rb b/spec/finders/milestones_finder_spec.rb
new file mode 100644
index 00000000000..32ec983c5b8
--- /dev/null
+++ b/spec/finders/milestones_finder_spec.rb
@@ -0,0 +1,90 @@
+require 'spec_helper'
+
+describe MilestonesFinder do
+  let(:group) { create(:group) }
+  let(:project_1) { create(:empty_project, namespace: group) }
+  let(:project_2) { create(:empty_project, namespace: group) }
+  let!(:milestone_1) { create(:milestone, group: group, title: 'one test', due_date: Date.today) }
+  let!(:milestone_2) { create(:milestone, group: group) }
+  let!(:milestone_3) { create(:milestone, project: project_1, state: 'active', due_date: Date.tomorrow) }
+  let!(:milestone_4) { create(:milestone, project: project_2, state: 'active') }
+
+  it 'it returns milestones for projects' do
+    result = described_class.new(project_ids: [project_1.id, project_2.id], state: 'all').execute
+
+    expect(result).to contain_exactly(milestone_3, milestone_4)
+  end
+
+  it 'returns milestones for groups' do
+    result = described_class.new(group_ids: group.id,  state: 'all').execute
+
+    expect(result).to contain_exactly(milestone_1, milestone_2)
+  end
+
+  it 'returns milestones for groups and projects' do
+    result = described_class.new(project_ids: [project_1.id, project_2.id], group_ids: group.id, state: 'all').execute
+
+    expect(result).to contain_exactly(milestone_1, milestone_2, milestone_3, milestone_4)
+  end
+
+  context 'with filters' do
+    let(:params) do
+      {
+        project_ids: [project_1.id, project_2.id],
+        group_ids: group.id,
+        state: 'all'
+      }
+    end
+
+    before do
+      milestone_1.close
+      milestone_3.close
+    end
+
+    it 'filters by active state' do
+      params[:state] = 'active'
+      result = described_class.new(params).execute
+
+      expect(result).to contain_exactly(milestone_2, milestone_4)
+    end
+
+    it 'filters by closed state' do
+      params[:state] = 'closed'
+      result = described_class.new(params).execute
+
+      expect(result).to contain_exactly(milestone_1, milestone_3)
+    end
+
+    it 'filters by title' do
+      result = described_class.new(params.merge(title: 'one test')).execute
+
+      expect(result.to_a).to contain_exactly(milestone_1)
+    end
+  end
+
+  context 'with order' do
+    let(:params) do
+      {
+        project_ids: [project_1.id, project_2.id],
+        group_ids: group.id,
+        state: 'all'
+      }
+    end
+
+    it "default orders by due date" do
+      result = described_class.new(params).execute
+
+      expect(result.first).to eq(milestone_1)
+      expect(result.second).to eq(milestone_3)
+    end
+
+    it "orders by parameter" do
+      result = described_class.new(params.merge(order: 'id DESC')).execute
+
+      expect(result.first).to eq(milestone_4)
+      expect(result.second).to eq(milestone_3)
+      expect(result.third).to eq(milestone_2)
+      expect(result.fourth).to eq(milestone_1)
+    end
+  end
+end
diff --git a/spec/fixtures/api/schemas/public_api/v3/issues.json b/spec/fixtures/api/schemas/public_api/v3/issues.json
index f2ee9c925ae..51b0822bc66 100644
--- a/spec/fixtures/api/schemas/public_api/v3/issues.json
+++ b/spec/fixtures/api/schemas/public_api/v3/issues.json
@@ -22,7 +22,8 @@
         "properties": {
           "id": { "type": "integer" },
           "iid": { "type": "integer" },
-          "project_id": { "type": "integer" },
+          "project_id": { "type": ["integer", "null"] },
+          "group_id": { "type": ["integer", "null"] },
           "title": { "type": "string" },
           "description": { "type": ["string", "null"] },
           "state": { "type": "string" },
diff --git a/spec/fixtures/api/schemas/public_api/v3/merge_requests.json b/spec/fixtures/api/schemas/public_api/v3/merge_requests.json
index 01f9fbb2c89..b5c74bcc26e 100644
--- a/spec/fixtures/api/schemas/public_api/v3/merge_requests.json
+++ b/spec/fixtures/api/schemas/public_api/v3/merge_requests.json
@@ -53,7 +53,8 @@
         "properties": {
           "id": { "type": "integer" },
           "iid": { "type": "integer" },
-          "project_id": { "type": "integer" },
+          "project_id": { "type": ["integer", "null"] },
+          "group_id": { "type": ["integer", "null"] },
           "title": { "type": "string" },
           "description": { "type": ["string", "null"] },
           "state": { "type": "string" },
diff --git a/spec/fixtures/api/schemas/public_api/v4/issues.json b/spec/fixtures/api/schemas/public_api/v4/issues.json
index 2d1c84ee93d..bd6bfc03199 100644
--- a/spec/fixtures/api/schemas/public_api/v4/issues.json
+++ b/spec/fixtures/api/schemas/public_api/v4/issues.json
@@ -22,7 +22,8 @@
         "properties": {
           "id": { "type": "integer" },
           "iid": { "type": "integer" },
-          "project_id": { "type": "integer" },
+          "project_id": { "type": ["integer", "null"] },
+          "group_id": { "type": ["integer", "null"] },
           "title": { "type": "string" },
           "description": { "type": ["string", "null"] },
           "state": { "type": "string" },
diff --git a/spec/fixtures/api/schemas/public_api/v4/merge_requests.json b/spec/fixtures/api/schemas/public_api/v4/merge_requests.json
index 51642e8cbb8..60aa47c1259 100644
--- a/spec/fixtures/api/schemas/public_api/v4/merge_requests.json
+++ b/spec/fixtures/api/schemas/public_api/v4/merge_requests.json
@@ -53,7 +53,8 @@
         "properties": {
           "id": { "type": "integer" },
           "iid": { "type": "integer" },
-          "project_id": { "type": "integer" },
+          "project_id": { "type": ["integer", "null"] },
+          "group_id": { "type": ["integer", "null"] },
           "title": { "type": "string" },
           "description": { "type": ["string", "null"] },
           "state": { "type": "string" },
diff --git a/spec/lib/gitlab/import_export/all_models.yml b/spec/lib/gitlab/import_export/all_models.yml
index 562f0c2991c..83fe26668cb 100644
--- a/spec/lib/gitlab/import_export/all_models.yml
+++ b/spec/lib/gitlab/import_export/all_models.yml
@@ -45,6 +45,7 @@ label:
 - merge_requests
 - priorities
 milestone:
+- group
 - project
 - issues
 - labels
diff --git a/spec/lib/gitlab/import_export/safe_model_attributes.yml b/spec/lib/gitlab/import_export/safe_model_attributes.yml
index b4a7e956686..4ef3db3721f 100644
--- a/spec/lib/gitlab/import_export/safe_model_attributes.yml
+++ b/spec/lib/gitlab/import_export/safe_model_attributes.yml
@@ -82,6 +82,7 @@ Milestone:
 - id
 - title
 - project_id
+- group_id
 - description
 - due_date
 - start_date
diff --git a/spec/models/milestone_spec.rb b/spec/models/milestone_spec.rb
index 45953023a36..2649d04bee3 100644
--- a/spec/models/milestone_spec.rb
+++ b/spec/models/milestone_spec.rb
@@ -6,9 +6,6 @@ describe Milestone, models: true do
       allow(subject).to receive(:set_iid).and_return(false)
     end
 
-    it { is_expected.to validate_presence_of(:title) }
-    it { is_expected.to validate_presence_of(:project) }
-
     describe 'start_date' do
       it 'adds an error when start_date is greated then due_date' do
         milestone = build(:milestone, start_date: Date.tomorrow, due_date: Date.yesterday)
@@ -37,17 +34,42 @@ describe Milestone, models: true do
     end
   end
 
-  describe "unique milestone title per project" do
-    it "does not accept the same title in a project twice" do
-      new_milestone = Milestone.new(project: milestone.project, title: milestone.title)
-      expect(new_milestone).not_to be_valid
+  describe "unique milestone title" do
+    context "per project" do
+      it "does not accept the same title in a project twice" do
+        new_milestone = Milestone.new(project: milestone.project, title: milestone.title)
+        expect(new_milestone).not_to be_valid
+      end
+
+      it "accepts the same title in another project" do
+        project = create(:empty_project)
+        new_milestone = Milestone.new(project: project, title: milestone.title)
+
+        expect(new_milestone).to be_valid
+      end
     end
 
-    it "accepts the same title in another project" do
-      project = build(:empty_project)
-      new_milestone = Milestone.new(project: project, title: milestone.title)
+    context "per group" do
+      let(:group) { create(:group) }
+      let(:milestone) { create(:milestone, group: group) }
+
+      before do
+        project.update(group: group)
+      end
+
+      it "does not accept the same title in a group twice" do
+        new_milestone = Milestone.new(group: group, title: milestone.title)
+
+        expect(new_milestone).not_to be_valid
+      end
 
-      expect(new_milestone).to be_valid
+      it "does not accept the same title of a child project milestone" do
+        create(:milestone, project: group.projects.first)
+
+        new_milestone = Milestone.new(group: group, title: milestone.title)
+
+        expect(new_milestone).not_to be_valid
+      end
     end
   end
 
diff --git a/spec/services/issues/move_service_spec.rb b/spec/services/issues/move_service_spec.rb
index d1dd1466d95..36d5038fb95 100644
--- a/spec/services/issues/move_service_spec.rb
+++ b/spec/services/issues/move_service_spec.rb
@@ -37,9 +37,6 @@ describe Issues::MoveService, services: true do
 
   describe '#execute' do
     shared_context 'issue move executed' do
-      let!(:milestone2) do
-        create(:milestone, project_id: new_project.id, title: 'v9.0')
-      end
       let!(:award_emoji) { create(:award_emoji, awardable: old_issue) }
 
       let!(:new_issue) { move_service.execute(old_issue, new_project) }
@@ -48,6 +45,63 @@ describe Issues::MoveService, services: true do
     context 'issue movable' do
       include_context 'user can move issue'
 
+      context 'move to new milestone'  do
+        let(:new_issue) { move_service.execute(old_issue, new_project) }
+
+        context 'project milestone' do
+          let!(:milestone2) do
+            create(:milestone, project_id: new_project.id, title: 'v9.0')
+          end
+
+          it 'assigns milestone to new issue' do
+            expect(new_issue.reload.milestone.title).to eq 'v9.0'
+            expect(new_issue.reload.milestone).to eq(milestone2)
+          end
+        end
+
+        context 'group milestones' do
+          let!(:group) { create(:group, :private) }
+          let!(:group_milestone_1) do
+            create(:milestone, group_id: group.id, title: 'v9.0_group')
+          end
+
+          before do
+            old_issue.update(milestone: group_milestone_1)
+            old_project.update(namespace: group)
+            new_project.update(namespace: group)
+
+            group.add_users([user], GroupMember::DEVELOPER)
+          end
+
+          context 'when moving to a project of the same group' do
+            it 'keeps the same group milestone' do
+              expect(new_issue.reload.project).to eq(new_project)
+              expect(new_issue.reload.milestone).to eq(group_milestone_1)
+            end
+          end
+
+          context 'when moving to a project of a different group' do
+            let!(:group_2) { create(:group, :private) }
+
+            let!(:group_milestone_2) do
+              create(:milestone, group_id: group_2.id, title: 'v9.0_group')
+            end
+
+            before do
+              old_issue.update(milestone: group_milestone_1)
+              new_project.update(namespace: group_2)
+
+              group_2.add_users([user], GroupMember::DEVELOPER)
+            end
+
+            it 'assigns to new group milestone of same title' do
+              expect(new_issue.reload.project).to eq(new_project)
+              expect(new_issue.reload.milestone).to eq(group_milestone_2)
+            end
+          end
+        end
+      end
+
       context 'generic issue' do
         include_context 'issue move executed'
 
@@ -55,11 +109,6 @@ describe Issues::MoveService, services: true do
           expect(new_issue.project).to eq new_project
         end
 
-        it 'assigns milestone to new issue' do
-          expect(new_issue.reload.milestone.title).to eq 'v9.0'
-          expect(new_issue.reload.milestone).to eq(milestone2)
-        end
-
         it 'assign labels to new issue' do
           expected_label_titles = new_issue.reload.labels.map(&:title)
           expect(expected_label_titles).to include 'label1'
diff --git a/spec/services/issues/update_service_spec.rb b/spec/services/issues/update_service_spec.rb
index c26642f5015..d0b991f19ab 100644
--- a/spec/services/issues/update_service_spec.rb
+++ b/spec/services/issues/update_service_spec.rb
@@ -253,13 +253,13 @@ describe Issues::UpdateService, services: true do
       end
 
       context 'when the milestone change' do
-        before do
+        it 'marks todos as done' do
           update_issue(milestone: create(:milestone))
-        end
 
-        it 'marks todos as done' do
           expect(todo.reload.done?).to eq true
         end
+
+        it_behaves_like 'system notes for milestones'
       end
 
       context 'when the labels change' do
diff --git a/spec/services/merge_requests/update_service_spec.rb b/spec/services/merge_requests/update_service_spec.rb
index ec15b5cac14..be62584ec0e 100644
--- a/spec/services/merge_requests/update_service_spec.rb
+++ b/spec/services/merge_requests/update_service_spec.rb
@@ -296,13 +296,13 @@ describe MergeRequests::UpdateService, services: true do
       end
 
       context 'when the milestone change' do
-        before do
+        it 'marks pending todos as done' do
           update_merge_request({ milestone: create(:milestone) })
-        end
 
-        it 'marks pending todos as done' do
           expect(pending_todo.reload).to be_done
         end
+
+        it_behaves_like 'system notes for milestones'
       end
 
       context 'when the labels change' do
diff --git a/spec/support/issuable_shared_examples.rb b/spec/support/issuable_shared_examples.rb
index 03011535351..970fe10db2b 100644
--- a/spec/support/issuable_shared_examples.rb
+++ b/spec/support/issuable_shared_examples.rb
@@ -5,3 +5,34 @@ shared_examples 'cache counters invalidator' do
     described_class.new(project, user, {}).execute(merge_request)
   end
 end
+
+shared_examples 'system notes for milestones' do
+  def update_issuable(opts)
+    issuable = try(:issue) || try(:merge_request)
+    described_class.new(project, user, opts).execute(issuable)
+  end
+
+  context 'group milestones' do
+    let(:group) { create(:group) }
+    let(:group_milestone) { create(:milestone, group: group) }
+
+    before do
+      project.update(namespace: group)
+      create(:group_member, group: group, user: user)
+    end
+
+    it 'does not create system note' do
+      expect do
+        update_issuable(milestone: group_milestone)
+      end.not_to change { Note.system.count }
+    end
+  end
+
+  context 'project milestones' do
+    it 'creates system note' do
+      expect do
+        update_issuable(milestone: create(:milestone))
+      end.to change { Note.system.count }.by(1)
+    end
+  end
+end