Merge branch 'empty-mrs' into 'master'

Allows empty merge requests for a workflow described in gitlab-org/gitlab-ce#14606

Closes gitlab-org/gitlab-ce#14606

See merge request !6384

1 files changed, 18 insertions, 2 deletions

diff --git a/spec/services/merge_requests/build_service_spec.rb b/spec/services/merge_requests/build_service_spec.rb
index 0d586e2216b..3a3f07ddcb9 100644
--- a/spec/services/merge_requests/build_service_spec.rb
+++ b/spec/services/merge_requests/build_service_spec.rb
@@ -52,12 +52,28 @@ describe MergeRequests::BuildService, services: true do
       end
     end
 
-    context 'no commits in the diff' do
-      let(:commits) { [] }
+    context 'same source and target branch' do
+      let(:source_branch) { 'master' }
 
       it 'forbids the merge request from being created' do
         expect(merge_request.can_be_created).to eq(false)
       end
+
+      it 'adds an error message to the merge request' do
+        expect(merge_request.errors).to contain_exactly('You must select different branches')
+      end
+    end
+
+    context 'no commits in the diff' do
+      let(:commits) { [] }
+
+      it 'allows the merge request to be created' do
+        expect(merge_request.can_be_created).to eq(true)
+      end
+
+      it 'adds a WIP prefix to the merge request title' do
+        expect(merge_request.title).to eq('WIP: Feature branch')
+      end
     end
 
     context 'one commit in the diff' do