Ensure validation messages are shown within the milestone form

* Remove call to Milestone#save! instead just Milestone#save
* Add safety specs to stop a regression

Fixes #22033

4 files changed, 41 insertions, 6 deletions

diff --git a/CHANGELOG b/CHANGELOG
index e9445a18a18..2394864467e 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -139,6 +139,7 @@ v 8.12.0 (unreleased)
   - Use default clone protocol on "check out, review, and merge locally" help page URL
   - API for Ci Lint !5953 (Katarzyna Kobierska Urszula Budziszewska)
   - Allow bulk update merge requests from merge requests index page
+  - Ensure validation messages are shown within the milestone form
   - Add notification_settings API calls !5632 (mahcsig)
   - Remove duplication between project builds and admin builds view !5680 (Katarzyna Kobierska Ula Budziszewska)
   - Fix URLs with anchors in wiki !6300 (houqp)
diff --git a/app/services/milestones/create_service.rb b/app/services/milestones/create_service.rb
index 3b90399af64..b8e08c9f1eb 100644
--- a/app/services/milestones/create_service.rb
+++ b/app/services/milestones/create_service.rb
@@ -3,7 +3,7 @@ module Milestones
     def execute
       milestone = project.milestones.new(params)
 
-      if milestone.save!
+      if milestone.save
         event_service.open_milestone(milestone, current_user)
       end
 
diff --git a/spec/features/milestone_spec.rb b/spec/features/milestone_spec.rb
index c43661e5681..b8c838bf7ab 100644
--- a/spec/features/milestone_spec.rb
+++ b/spec/features/milestone_spec.rb
@@ -3,9 +3,8 @@ require 'rails_helper'
 feature 'Milestone', feature: true do
   include WaitForAjax
 
-  let(:project) { create(:project, :public) }
+  let(:project) { create(:empty_project, :public) }
   let(:user)   { create(:user) }
-  let(:milestone) { create(:milestone, project: project, title: 8.7) }
 
   before do
     project.team << [user, :master]
@@ -13,7 +12,7 @@ feature 'Milestone', feature: true do
   end
 
   feature 'Create a milestone' do
-    scenario 'shows an informative message for a new issue' do
+    scenario 'shows an informative message for a new milestone' do
       visit new_namespace_project_milestone_path(project.namespace, project)
       page.within '.milestone-form' do
         fill_in "milestone_title", with: '8.7'
@@ -26,10 +25,26 @@ feature 'Milestone', feature: true do
 
   feature 'Open a milestone with closed issues' do
     scenario 'shows an informative message' do
+      milestone = create(:milestone, project: project, title: 8.7)
+
       create(:issue, title: "Bugfix1", project: project, milestone: milestone, state: "closed")
       visit namespace_project_milestone_path(project.namespace, project, milestone)
 
       expect(find('.alert-success')).to have_content('All issues for this milestone are closed. You may close this milestone now.')
     end
   end
+
+  feature 'Open a milestone with an existing title' do
+    scenario 'displays validation message' do
+      milestone = create(:milestone, project: project, title: 8.7)
+
+      visit new_namespace_project_milestone_path(project.namespace, project)
+      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('Title has already been taken')
+    end
+  end
 end
diff --git a/spec/requests/api/milestones_spec.rb b/spec/requests/api/milestones_spec.rb
index d6a0c656e74..b89dac01040 100644
--- a/spec/requests/api/milestones_spec.rb
+++ b/spec/requests/api/milestones_spec.rb
@@ -3,7 +3,7 @@ require 'spec_helper'
 describe API::API, api: true  do
   include ApiHelpers
   let(:user) { create(:user) }
-  let!(:project) { create(:project, namespace: user.namespace ) }
+  let!(:project) { create(:empty_project, namespace: user.namespace ) }
   let!(:closed_milestone) { create(:closed_milestone, project: project) }
   let!(:milestone) { create(:milestone, project: project) }
 
@@ -12,6 +12,7 @@ describe API::API, api: true  do
   describe 'GET /projects/:id/milestones' do
     it 'returns project milestones' do
       get api("/projects/#{project.id}/milestones", user)
+
       expect(response).to have_http_status(200)
       expect(json_response).to be_an Array
       expect(json_response.first['title']).to eq(milestone.title)
@@ -19,6 +20,7 @@ describe API::API, api: true  do
 
     it 'returns a 401 error if user not authenticated' do
       get api("/projects/#{project.id}/milestones")
+
       expect(response).to have_http_status(401)
     end
 
@@ -44,6 +46,7 @@ describe API::API, api: true  do
   describe 'GET /projects/:id/milestones/:milestone_id' do
     it 'returns a project milestone by id' do
       get api("/projects/#{project.id}/milestones/#{milestone.id}", user)
+
       expect(response).to have_http_status(200)
       expect(json_response['title']).to eq(milestone.title)
       expect(json_response['iid']).to eq(milestone.iid)
@@ -60,11 +63,13 @@ describe API::API, api: true  do
 
     it 'returns 401 error if user not authenticated' do
       get api("/projects/#{project.id}/milestones/#{milestone.id}")
+
       expect(response).to have_http_status(401)
     end
 
     it 'returns a 404 error if milestone id not found' do
       get api("/projects/#{project.id}/milestones/1234", user)
+
       expect(response).to have_http_status(404)
     end
   end
@@ -72,6 +77,7 @@ describe API::API, api: true  do
   describe 'POST /projects/:id/milestones' do
     it 'creates a new project milestone' do
       post api("/projects/#{project.id}/milestones", user), title: 'new milestone'
+
       expect(response).to have_http_status(201)
       expect(json_response['title']).to eq('new milestone')
       expect(json_response['description']).to be_nil
@@ -80,6 +86,7 @@ describe API::API, api: true  do
     it 'creates a new project milestone with description and due date' do
       post api("/projects/#{project.id}/milestones", user),
         title: 'new milestone', description: 'release', due_date: '2013-03-02'
+
       expect(response).to have_http_status(201)
       expect(json_response['description']).to eq('release')
       expect(json_response['due_date']).to eq('2013-03-02')
@@ -87,6 +94,14 @@ describe API::API, api: true  do
 
     it 'returns a 400 error if title is missing' do
       post api("/projects/#{project.id}/milestones", user)
+
+      expect(response).to have_http_status(400)
+    end
+
+    it 'returns a 400 error if params are invalid (duplicate title)' do
+      post api("/projects/#{project.id}/milestones", user),
+        title: milestone.title, description: 'release', due_date: '2013-03-02'
+
       expect(response).to have_http_status(400)
     end
   end
@@ -95,6 +110,7 @@ describe API::API, api: true  do
     it 'updates a project milestone' do
       put api("/projects/#{project.id}/milestones/#{milestone.id}", user),
         title: 'updated title'
+
       expect(response).to have_http_status(200)
       expect(json_response['title']).to eq('updated title')
     end
@@ -102,6 +118,7 @@ describe API::API, api: true  do
     it 'returns a 404 error if milestone id not found' do
       put api("/projects/#{project.id}/milestones/1234", user),
         title: 'updated title'
+
       expect(response).to have_http_status(404)
     end
   end
@@ -131,6 +148,7 @@ describe API::API, api: true  do
     end
     it 'returns project issues for a particular milestone' do
       get api("/projects/#{project.id}/milestones/#{milestone.id}/issues", user)
+
       expect(response).to have_http_status(200)
       expect(json_response).to be_an Array
       expect(json_response.first['milestone']['title']).to eq(milestone.title)
@@ -138,11 +156,12 @@ describe API::API, api: true  do
 
     it 'returns a 401 error if user not authenticated' do
       get api("/projects/#{project.id}/milestones/#{milestone.id}/issues")
+
       expect(response).to have_http_status(401)
     end
 
     describe 'confidential issues' do
-      let(:public_project) { create(:project, :public) }
+      let(:public_project) { create(:empty_project, :public) }
       let(:milestone) { create(:milestone, project: public_project) }
       let(:issue) { create(:issue, project: public_project) }
       let(:confidential_issue) { create(:issue, confidential: true, project: public_project) }