Implemented notes (body) patching in API.

app/services/notes/update_service.rb

+module Notes
+  class UpdateService < BaseService
+    def execute
+      note = project.notes.find(params[:note_id])
+      note.note = params[:note]
+      if note.save
+        notification_service.new_note(note)
+
+        # Skip system notes, like status changes and cross-references.
+        unless note.system
+          event_service.leave_note(note, note.author)
+
+          # Create a cross-reference note if this Note contains GFM that
+          # names an issue, merge request, or commit.
+          note.references.each do |mentioned|
+            Note.create_cross_reference_note(mentioned, note.noteable,
+                                             note.author, note.project)
+          end
+        end
+      end
+
+      note
+    end
+  end
+end

doc/api/notes.md

@@ -78,6 +78,21 @@ Parameters:
 - `issue_id` (required) - The ID of an issue
 - `body` (required) - The content of a note
 
+### Modify existing issue note
+
+Modify existing note of an issue.
+
+```
+PUT /projects/:id/issues/:issue_id/notes/:note_id
+```
+
+Parameters:
+
+- `id` (required) - The ID of a project
+- `issue_id` (required) - The ID of an issue
+- `note_id` (required) - The ID of a note
+- `body` (required) - The content of a note
+
 ## Snippets
 
 ### List all snippet notes
@@ -137,7 +152,22 @@ POST /projects/:id/snippets/:snippet_id/notes
 Parameters:
 
 - `id` (required) - The ID of a project
-- `snippet_id` (required) - The ID of an snippet
+- `snippet_id` (required) - The ID of a snippet
+- `body` (required) - The content of a note
+
+### Modify existing snippet note
+
+Modify existing note of a snippet.
+
+```
+PUT /projects/:id/snippets/:snippet_id/notes/:note_id
+```
+
+Parameters:
+
+- `id` (required) - The ID of a project
+- `snippet_id` (required) - The ID of a snippet
+- `note_id` (required) - The ID of a note
 - `body` (required) - The content of a note
 
 ## Merge Requests
@@ -199,3 +229,18 @@ Parameters:
 - `id` (required) - The ID of a project
 - `merge_request_id` (required) - The ID of a merge request
 - `body` (required) - The content of a note
+
+### Modify existing merge request note
+
+Modify existing note of a merge request.
+
+```
+PUT /projects/:id/merge_requests/:merge_request_id/notes/:note_id
+```
+
+Parameters:
+
+- `id` (required) - The ID of a project
+- `merge_request_id` (required) - The ID of a merge request
+- `note_id` (required) - The ID of a note
+- `body` (required) - The content of a note

lib/api/notes.rb

@@ -64,6 +64,39 @@ module API
             not_found!
           end
         end
+
+        # Modify existing +noteable+ note
+        #
+        # Parameters:
+        #   id (required) - The ID of a project
+        #   noteable_id (required) - The ID of an issue or snippet
+        #   node_id (required) - The ID of a note
+        #   body (required) - New content of a note
+        # Example Request:
+        #   PUT /projects/:id/issues/:noteable_id/notes/:note_id
+        #   PUT /projects/:id/snippets/:noteable_id/notes/:node_id
+        put ":id/#{noteables_str}/:#{noteable_id_str}/notes/:note_id" do
+          required_attributes! [:body]
+
+          authorize! :admin_note, user_project.notes.find(params[:note_id])
+
+          opts = {
+            note: params[:body],
+            note_id: params[:note_id],
+            noteable_type: noteables_str.classify,
+            noteable_id: params[noteable_id_str]
+          }
+
+          @note = ::Notes::UpdateService.new(user_project, current_user,
+                                             opts).execute
+
+          if @note.valid?
+            present @note, with: Entities::Note
+          else
+            bad_request!('Invalid note')
+          end
+        end
+
       end
     end
   end

spec/requests/api/notes_spec.rb

@@ -131,4 +131,58 @@ describe API::API, api: true  do
       post api("/projects/#{project.id}/issues/#{issue.id}/notes", user), body: 'hi!'
     end
   end
+
+  describe 'PUT /projects/:id/noteable/:noteable_id/notes/:note_id' do
+    context 'when noteable is an Issue' do
+      it 'should return modified note' do
+        put api("/projects/#{project.id}/issues/#{issue.id}/"\
+                  "notes/#{issue_note.id}", user), body: 'Hello!'
+        response.status.should == 200
+        json_response['body'].should == 'Hello!'
+      end
+
+      it 'should return a 404 error when note id not found' do
+        put api("/projects/#{project.id}/issues/#{issue.id}/notes/123", user),
+                body: 'Hello!'
+        response.status.should == 404
+      end
+
+      it 'should return a 400 bad request error if body not given' do
+        put api("/projects/#{project.id}/issues/#{issue.id}/"\
+                  "notes/#{issue_note.id}", user)
+        response.status.should == 400
+      end
+    end
+
+    context 'when noteable is a Snippet' do
+      it 'should return modified note' do
+        put api("/projects/#{project.id}/snippets/#{snippet.id}/"\
+                  "notes/#{snippet_note.id}", user), body: 'Hello!'
+        response.status.should == 200
+        json_response['body'].should == 'Hello!'
+      end
+
+      it 'should return a 404 error when note id not found' do
+        put api("/projects/#{project.id}/snippets/#{snippet.id}/"\
+                  "notes/123", user), body: "Hello!"
+        response.status.should == 404
+      end
+    end
+
+    context 'when noteable is a Merge Request' do
+      it 'should return modified note' do
+        put api("/projects/#{project.id}/merge_requests/#{merge_request.id}/"\
+                  "notes/#{merge_request_note.id}", user), body: 'Hello!'
+        response.status.should == 200
+        json_response['body'].should == 'Hello!'
+      end
+
+      it 'should return a 404 error when note id not found' do
+        put api("/projects/#{project.id}/merge_requests/#{merge_request.id}/"\
+                  "notes/123", user), body: "Hello!"
+        response.status.should == 404
+      end
+    end
+  end
+
 end