5 files changed, 77 insertions, 0 deletions

diff --git a/app/assets/javascripts/notes.js b/app/assets/javascripts/notes.js
index 603db88567d..0016070b648 100644
--- a/app/assets/javascripts/notes.js
+++ b/app/assets/javascripts/notes.js
@@ -3,6 +3,7 @@
 /* global GLForm */
 /* global Autosave */
 /* global ResolveService */
+/* global mrRefreshWidgetUrl */
 
 /*= require autosave */
 /*= require autosize */
@@ -244,6 +245,16 @@
     };
 
 
+    Notes.prototype.handleCreateChanges = function(note) {
+      if (typeof note === 'undefined') {
+        return;
+      }
+
+      if (note.commands_changes && note.commands_changes.includes('merge')) {
+        $.get(mrRefreshWidgetUrl);
+      }
+    };
+
     /*
     Render note in main comments area.
 
@@ -429,6 +440,7 @@
      */
 
     Notes.prototype.addNote = function(xhr, note, status) {
+      this.handleCreateChanges(note);
       return this.renderNote(note);
     };
 
diff --git a/app/controllers/projects/merge_requests_controller.rb b/app/controllers/projects/merge_requests_controller.rb
index 6004e7d7115..72dcf020c9f 100644
--- a/app/controllers/projects/merge_requests_controller.rb
+++ b/app/controllers/projects/merge_requests_controller.rb
@@ -347,6 +347,16 @@ class Projects::MergeRequestsController < Projects::ApplicationController
     end
   end
 
+  def merge_widget_refresh
+    if merge_request.in_progress_merge_commit_sha
+      @status = :success
+    elsif merge_request.merge_when_build_succeeds
+      @status = :merge_when_build_succeeds
+    end
+
+    render 'merge'
+  end
+
   def branch_from
     # This is always source
     @source_project = @merge_request.nil? ? @project : @merge_request.source_project
diff --git a/app/views/projects/merge_requests/_show.html.haml b/app/views/projects/merge_requests/_show.html.haml
index 1f63803c24e..2e7cd52df1e 100644
--- a/app/views/projects/merge_requests/_show.html.haml
+++ b/app/views/projects/merge_requests/_show.html.haml
@@ -112,3 +112,5 @@
   merge_request = new MergeRequest({
     action: "#{controller.action_name}"
   });
+
+  var mrRefreshWidgetUrl = "#{@merge_request && @merge_request.source_project ? merge_widget_refresh_namespace_project_merge_request_url(@merge_request.source_project.namespace, @merge_request.source_project, @merge_request) : ''}";
diff --git a/config/routes/project.rb b/config/routes/project.rb
index 26e2dc9e6e7..1fc6ed28c74 100644
--- a/config/routes/project.rb
+++ b/config/routes/project.rb
@@ -94,6 +94,7 @@ constraints(ProjectUrlConstrainer.new) do
           get :pipelines
           get :merge_check
           post :merge
+          get :merge_widget_refresh
           post :cancel_merge_when_build_succeeds
           get :ci_status
           get :ci_environments_status
diff --git a/spec/controllers/projects/merge_requests_controller_spec.rb b/spec/controllers/projects/merge_requests_controller_spec.rb
index 2a411d78395..c6a38863cf5 100644
--- a/spec/controllers/projects/merge_requests_controller_spec.rb
+++ b/spec/controllers/projects/merge_requests_controller_spec.rb
@@ -1048,4 +1048,56 @@ describe Projects::MergeRequestsController do
       end
     end
   end
+
+  describe 'GET merge_widget_refresh' do
+    let(:params) do
+      {
+        namespace_id: project.namespace.path,
+        project_id: project.path,
+        id: merge_request.iid,
+        format: :raw
+      }
+    end
+
+    before do
+      project.team << [user, :developer]
+      xhr :get, :merge_widget_refresh, params
+    end
+
+    context 'when merge in progress' do
+      let(:merge_request) { create(:merge_request, source_project: project, in_progress_merge_commit_sha: 'sha') }
+
+      it 'returns an OK response' do
+        expect(response).to have_http_status(:ok)
+      end
+
+      it 'returns :success' do
+        expect(assigns(:status)).to eq(:success)
+      end
+    end
+
+    context 'when waiting for build' do
+      let(:merge_request) { create(:merge_request, source_project: project, merge_when_build_succeeds: true, merge_user: user) }
+
+      it 'returns an OK response' do
+        expect(response).to have_http_status(:ok)
+      end
+
+      it 'returns :merge_when_build_succeeds' do
+        expect(assigns(:status)).to eq(:merge_when_build_succeeds)
+      end
+    end
+
+    context 'when no special status for MR' do
+      let(:merge_request) { create(:merge_request, source_project: project) }
+
+      it 'returns an OK response' do
+        expect(response).to have_http_status(:ok)
+      end
+
+      it 'returns nil' do
+        expect(assigns(:status)).to be_nil
+      end
+    end
+  end
 end