Add method to get the comments on a merge request

Add method to get the comments for a merge request and
document that you can change the status of a merge request.

doc/api/merge_requests.md

@@ -150,6 +150,7 @@ Parameters:
 + `target_branch`               - The target branch
 + `assignee_id`                 - Assignee user ID
 + `title`                       - Title of MR
++ `state_event`                 - New state (close|reopen|merge)
 
 ```json
 
@@ -210,3 +211,44 @@ Parameters:
     "note":"text1"
 }
 ```
+
+
+## Get the comments on a MR
+
+Gets all the comments associated with a merge request.
+
+```
+GET /projects/:id/merge_request/:merge_request_id/comments
+```
+
+Parameters:
+
++ `id` (required) - The ID of a project
++ `merge_request_id` (required) - ID of merge request
+
+```json
+[
+    {
+       "note":"this is the 1st comment on the 2merge merge request",
+       "author":{
+           "id":11,
+           "username":"admin",
+           "email":"admin@local.host",
+           "name":"Administrator",
+           "state":"active",
+           "created_at":"2014-03-06T08:17:35.000Z"
+       }
+    },
+    {
+       "note":"_Status changed to closed_",
+       "author":{
+           "id":11,
+           "username":"admin",
+           "email":"admin@local.host",
+           "name":"Administrator",
+           "state":"active",
+           "created_at":"2014-03-06T08:17:35.000Z"
+       }
+    }
+]
+```

lib/api/merge_requests.rb

@@ -125,6 +125,22 @@ module API
         end
       end
 
+      # Get a merge request's comments
+      #
+      # Parameters:
+      #   id (required) - The ID of a project
+      #   merge_request_id (required) - ID of MR
+      # Examples:
+      #   GET /projects/:id/merge_request/:merge_request_id/comments
+      #
+      get ":id/merge_request/:merge_request_id/comments" do
+        merge_request = user_project.merge_requests.find(params[:merge_request_id])
+
+        authorize! :read_merge_request, merge_request
+
+        present paginate(merge_request.notes), with: Entities::MRNote
+      end
+
       # Post comment to merge request
       #
       # Parameters:

spec/requests/api/merge_requests_spec.rb

@@ -7,6 +7,7 @@ describe API::API do
   let(:user) { create(:user) }
   let!(:project) {create(:project, creator_id: user.id, namespace: user.namespace) }
   let!(:merge_request) { create(:merge_request, author: user, assignee: user, source_project: project, target_project: project, title: "Test") }
+  let!(:note) { create(:note_on_merge_request, author: user, project: project, noteable: merge_request, note: "a comment on a MR") }
   before {
     project.team << [user, :reporters]
   }
@@ -205,4 +206,20 @@ describe API::API do
       response.status.should == 404
     end
   end
+
+  describe "GET :id/merge_request/:merge_request_id/comments" do
+    it "should return merge_request comments" do
+      get api("/projects/#{project.id}/merge_request/#{merge_request.id}/comments", user)
+      response.status.should == 200
+      json_response.should be_an Array
+      json_response.length.should == 1
+      json_response.first['note'].should == "a comment on a MR"
+      json_response.first['author']['id'].should == user.id
+    end
+
+    it "should return a 404 error if merge_request_id not found" do
+      get api("/projects/#{project.id}/merge_request/999/comments", user)
+      response.status.should == 404
+    end
+  end
 end