Improve JIRA event descriptions

app/helpers/services_helper.rb

 module ServicesHelper
-  def service_event_description(event)
-    case event
-    when "push", "push_events"
-      "Event will be triggered by a push to the repository"
-    when "tag_push", "tag_push_events"
-      "Event will be triggered when a new tag is pushed to the repository"
-    when "note", "note_events"
-      "Event will be triggered when someone adds a comment"
-    when "issue", "issue_events"
-      "Event will be triggered when an issue is created/updated/closed"
-    when "confidential_issue", "confidential_issue_events"
-      "Event will be triggered when a confidential issue is created/updated/closed"
-    when "merge_request", "merge_request_events"
-      "Event will be triggered when a merge request is created/updated/merged"
-    when "pipeline", "pipeline_events"
-      "Event will be triggered when a pipeline status changes"
-    when "wiki_page", "wiki_page_events"
-      "Event will be triggered when a wiki page is created/updated"
-    when "commit", "commit_events"
-      "Event will be triggered when a commit is created/updated"
-    end
-  end
-
   def service_event_field_name(event)
     event = event.pluralize if %w[merge_request issue confidential_issue].include?(event)
     "#{event}_events"

app/models/project_services/jira_service.rb

@@ -14,9 +14,8 @@ class JiraService < IssueTrackerService
   alias_method :project_url, :url
-  # This is confusing, but JiraService does not really support these events.
-  # The values here are required to display correct options in the service
-  # configuration screen.
+  # When these are false GitLab does not create cross reference
+  # comments on JIRA except when an issue gets transitioned.
   def self.supported_events
     %w(commit merge_request)
   end
@@ -318,4 +317,13 @@ class JiraService < IssueTrackerService
     url_changed?
   end
+
+  def self.event_description(event)
+    case event
+    when "merge_request", "merge_request_events"
+      "JIRA comments will be created when an issue gets referenced in a merge request."
+    when "commit", "commit_events"
+      "JIRA comments will be created when an issue gets referenced in a commit."
+    end
+  end
 end

app/models/service.rb

@@ -304,6 +304,29 @@ class Service < ActiveRecord::Base
     end
   end
+  def self.event_description(event)
+    case event
+    when "push", "push_events"
+      "Event will be triggered by a push to the repository"
+    when "tag_push", "tag_push_events"
+      "Event will be triggered when a new tag is pushed to the repository"
+    when "note", "note_events"
+      "Event will be triggered when someone adds a comment"
+    when "issue", "issue_events"
+      "Event will be triggered when an issue is created/updated/closed"
+    when "confidential_issue", "confidential_issue_events"
+      "Event will be triggered when a confidential issue is created/updated/closed"
+    when "merge_request", "merge_request_events"
+      "Event will be triggered when a merge request is created/updated/merged"
+    when "pipeline", "pipeline_events"
+      "Event will be triggered when a pipeline status changes"
+    when "wiki_page", "wiki_page_events"
+      "Event will be triggered when a wiki page is created/updated"
+    when "commit", "commit_events"
+      "Event will be triggered when a commit is created/updated"
+    end
+  end
+
   def valid_recipients?
     activated? && !importing?
   end

app/views/shared/_service_settings.html.haml

@@ -33,7 +33,7 @@
               = form.text_field field[:name], class: "form-control", placeholder: field[:placeholder]
           %p.light
-            = service_event_description(event)
+            = @service.class.event_description(event)
   - @service.global_fields.each do |field|
     - type = field[:type]

changelogs/unreleased/issue_25542.yml

+---
+title: Improve JIRA event descriptions
+merge_request:
+author:
+type: other

lib/api/services.rb

@@ -735,7 +735,7 @@ module API
           required: false,
           name: event_name.to_sym,
           type: String,
-          desc: ServicesHelper.service_event_description(event_name)
+          desc: service.event_description(event_name)
         }
       end
     end

spec/services/system_note_service_spec.rb

@@ -743,7 +743,7 @@ describe SystemNoteService do
           expect(cross_reference(type)).to eq("Events for #{type.pluralize.humanize.downcase} are disabled.")
         end
-        it "blocks cross reference when #{type.underscore}_events is true" do
+        it "creates cross reference when #{type.underscore}_events is true" do
           jira_tracker.update("#{type}_events" => true)
           expect(cross_reference(type)).to eq(success_message)

spec/views/projects/services/_form.haml_spec.rb

+require 'spec_helper'
+
+describe 'projects/services/_form' do
+  let(:project) { create(:redmine_project) }
+  let(:user) { create(:admin) }
+
+  before do
+    assign(:project, project)
+
+    allow(controller).to receive(:current_user).and_return(user)
+
+    allow(view).to receive_messages(current_user: user,
+                                    can?: true,
+                                    current_application_settings: Gitlab::CurrentSettings.current_application_settings)
+  end
+
+  context 'commit_events and merge_request_events' do
+    before do
+      assign(:service, project.redmine_service)
+    end
+
+    it 'display merge_request_events and commit_events descriptions' do
+      allow(RedmineService).to receive(:supported_events).and_return(%w(commit merge_request))
+
+      render
+
+      expect(rendered).to have_content('Event will be triggered when a commit is created/updated')
+      expect(rendered).to have_content('Event will be triggered when a merge request is created/updated/merged')
+    end
+
+    context 'when service is JIRA' do
+      let(:project) { create(:jira_project) }
+
+      before do
+        assign(:service, project.jira_service)
+      end
+
+      it 'display merge_request_events and commit_events descriptions' do
+        render
+
+        expect(rendered).to have_content('JIRA comments will be created when an issue gets referenced in a commit.')
+        expect(rendered).to have_content('JIRA comments will be created when an issue gets referenced in a merge request.')
+      end
+    end
+  end
+end