Add button to delete all merged branches

It adds a button to the branches page that the user can use to delete
all the branches that are already merged. This can be used to clean up
all the branches that were forgotten to delete while merging MRs.

Fixes #21076.

1 files changed, 54 insertions, 0 deletions

diff --git a/spec/services/delete_merged_branches_service_spec.rb b/spec/services/delete_merged_branches_service_spec.rb
new file mode 100644
index 00000000000..181488e89c7
--- /dev/null
+++ b/spec/services/delete_merged_branches_service_spec.rb
@@ -0,0 +1,54 @@
+require 'spec_helper'
+
+describe DeleteMergedBranchesService, services: true do
+  subject(:service) { described_class.new(project, project.owner) }
+
+  let(:project) { create(:project) }
+
+  context '#execute' do
+    context 'unprotected branches' do
+      before do
+        service.execute
+      end
+
+      it 'deletes a branch that was merged' do
+        expect(project.repository.branch_names).not_to include('improve/awesome')
+      end
+
+      it 'keeps branch that is unmerged' do
+        expect(project.repository.branch_names).to include('feature')
+      end
+
+      it 'keeps "master"' do
+        expect(project.repository.branch_names).to include('master')
+      end
+    end
+
+    context 'protected branches' do
+      before do
+        create(:protected_branch, name: 'improve/awesome', project: project)
+        service.execute
+      end
+
+      it 'keeps protected branch' do
+        expect(project.repository.branch_names).to include('improve/awesome')
+      end
+    end
+
+    context 'user without rights' do
+      let(:user) { create(:user) }
+
+      it 'cannot execute' do
+        expect { described_class.new(project, user).execute }.to raise_error(Gitlab::Access::AccessDeniedError)
+      end
+    end
+  end
+
+  context '#async_execute' do
+    it 'calls DeleteMergedBranchesWorker async' do
+      expect(DeleteMergedBranchesWorker).to receive(:perform_async)
+
+      service.async_execute
+    end
+  end
+end