Merge branch 'api-isssues-due-date' into 'master'

API: Expose due_date for issues

## What does this MR do?

Add support for the `due_date` of issues to the API.

## What are the relevant issue numbers?

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/18696

## Does this MR meet the acceptance criteria?

- [x] [CHANGELOG](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CHANGELOG) entry added
- [x] [Documentation created/updated](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/development/doc_styleguide.md)
- [x] API support added
- Tests
  - [x] Added for this feature/bug
  - [x] All builds are passing
- [x] Conform by the [style guides](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CONTRIBUTING.md#style-guides)
- [x] Branch has no merge conflicts with `master` (if you do - rebase it please)
- [x] [Squashed related commits together](https://git-scm.com/book/en/Git-Tools-Rewriting-History#Squashing-Commits)

See merge request !5212

2 files changed, 7 insertions, 4 deletions

diff --git a/lib/api/entities.rb b/lib/api/entities.rb
index 8e03c08f47b..3c79a00eb8c 100644
--- a/lib/api/entities.rb
+++ b/lib/api/entities.rb
@@ -187,6 +187,7 @@ module API
       end
       expose :user_notes_count
       expose :upvotes, :downvotes
+      expose :due_date
     end
 
     class ExternalIssue < Grape::Entity
diff --git a/lib/api/issues.rb b/lib/api/issues.rb
index 8a03a41e9c5..c588103e517 100644
--- a/lib/api/issues.rb
+++ b/lib/api/issues.rb
@@ -152,12 +152,13 @@ module API
       #   milestone_id (optional) - The ID of a milestone to assign issue
       #   labels (optional)       - The labels of an issue
       #   created_at (optional)   - Date time string, ISO 8601 formatted
+      #   due_date (optional)     - Date time string in the format YEAR-MONTH-DAY
       # Example Request:
       #   POST /projects/:id/issues
-      post ":id/issues" do
+      post ':id/issues' do
         required_attributes! [:title]
 
-        keys = [:title, :description, :assignee_id, :milestone_id]
+        keys = [:title, :description, :assignee_id, :milestone_id, :due_date]
         keys << :created_at if current_user.admin? || user_project.owner == current_user
         attrs = attributes_for_keys(keys)
 
@@ -201,12 +202,13 @@ module API
       #   labels (optional) - The labels of an issue
       #   state_event (optional) - The state event of an issue (close|reopen)
       #   updated_at (optional) - Date time string, ISO 8601 formatted
+      #   due_date (optional)     - Date time string in the format YEAR-MONTH-DAY
       # Example Request:
       #   PUT /projects/:id/issues/:issue_id
-      put ":id/issues/:issue_id" do
+      put ':id/issues/:issue_id' do
         issue = user_project.issues.find(params[:issue_id])
         authorize! :update_issue, issue
-        keys = [:title, :description, :assignee_id, :milestone_id, :state_event]
+        keys = [:title, :description, :assignee_id, :milestone_id, :state_event, :due_date]
         keys << :updated_at if current_user.admin? || user_project.owner == current_user
         attrs = attributes_for_keys(keys)