Merge branch 'fix/import-services' into 'master'

Fixes issue with rails reserved keyword type exporting/importing services.

The attribute `type`in services was being ignored by Import/Export. Added `type` as a method call in the export, as `type` gets ignored invoking `to_json`, manually adding this as a method in `import_export.yml` solves the problem.

On a different note, I found assigning a title directly to `CustomIssueTrackerService` didn't play very well with `prop_accessor`:

```ruby
> CustomIssueTrackerService.new(title: 'asdf')
NoMethodError: undefined method `[]=' for nil:NilClass
> CustomIssueTrackerService.new(title: nil)
NoMethodError: undefined method `[]=' for nil:NilClass
```

This was also causing the Import/Export to failed... So I added a custom setter that fixed the problem.

Fixes https://gitlab.com/gitlab-org/gitlab-ce/issues/22461

See merge request !6499
Conflicts:
	spec/lib/gitlab/import_export/project_tree_restorer_spec.rb

app/models/project_services/custom_issue_tracker_service.rb

@@ -9,6 +9,10 @@ class CustomIssueTrackerService < IssueTrackerService
     end
   end
 
+  def title=(value)
+    self.properties['title'] = value if self.properties
+  end
+
   def description
     if self.properties && self.properties['description'].present?
       self.properties['description']

lib/gitlab/import_export/import_export.yml

@@ -73,5 +73,7 @@ excluded_attributes:
 methods:
   statuses:
     - :type
+  services:
+    - :type
   merge_request_diff:
     - :utf8_st_diffs

spec/lib/gitlab/import_export/project.json

@@ -6943,6 +6943,7 @@
       "note_events": true,
       "build_events": true,
       "category": "issue_tracker",
+      "type": "CustomIssueTrackerService",
       "default": true,
       "wiki_page_events": true
     },

spec/lib/gitlab/import_export/project_tree_saver_spec.rb

@@ -111,6 +111,10 @@ describe Gitlab::ImportExport::ProjectTreeSaver, services: true do
         expect(saved_project_json['issues'].first['label_links'].first['label']).not_to be_empty
       end
 
+      it 'saves the correct service type' do
+        expect(saved_project_json['services'].first['type']).to eq('CustomIssueTrackerService')
+      end
+
       it 'has project feature' do
         project_feature = saved_project_json['project_feature']
         expect(project_feature).not_to be_empty
@@ -161,6 +165,7 @@ describe Gitlab::ImportExport::ProjectTreeSaver, services: true do
            commit_id: ci_pipeline.sha)
 
     create(:event, target: milestone, project: project, action: Event::CREATED, author: user)
+    create(:service, project: project, type: 'CustomIssueTrackerService', category: 'issue_tracker')
 
     project.project_feature.update_attribute(:issues_access_level, ProjectFeature::DISABLED)
     project.project_feature.update_attribute(:wiki_access_level, ProjectFeature::ENABLED)

spec/models/project_services/custom_issue_tracker_service_spec.rb

@@ -25,5 +25,21 @@ describe CustomIssueTrackerService, models: true do
       it { is_expected.not_to validate_presence_of(:issues_url) }
       it { is_expected.not_to validate_presence_of(:new_issue_url) }
     end
+
+    context 'title' do
+      let(:issue_tracker) { described_class.new(properties: {}) }
+
+      it 'sets a default title' do
+        issue_tracker.title = nil
+
+        expect(issue_tracker.title).to eq('Custom Issue Tracker')
+      end
+
+      it 'sets the custom title' do
+        issue_tracker.title = 'test title'
+
+        expect(issue_tracker.title).to eq('test title')
+      end
+    end
   end
 end