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.

4 files changed, 143 insertions, 4 deletions

diff --git a/spec/controllers/projects/branches_controller_spec.rb b/spec/controllers/projects/branches_controller_spec.rb
index 644de308c64..f7cf006efd6 100644
--- a/spec/controllers/projects/branches_controller_spec.rb
+++ b/spec/controllers/projects/branches_controller_spec.rb
@@ -1,13 +1,13 @@
 require 'spec_helper'
 
 describe Projects::BranchesController do
-  let(:project) { create(:project) }
-  let(:user)    { create(:user) }
+  let(:project)   { create(:project) }
+  let(:user)      { create(:user) }
+  let(:developer) { create(:user) }
 
   before do
-    sign_in(user)
-
     project.team << [user, :master]
+    project.team << [user, :developer]
 
     allow(project).to receive(:branches).and_return(['master', 'foo/bar/baz'])
     allow(project).to receive(:tags).and_return(['v1.0.0', 'v2.0.0'])
@@ -19,6 +19,8 @@ describe Projects::BranchesController do
 
     context "on creation of a new branch" do
       before do
+        sign_in(user)
+
         post :create,
           namespace_id: project.namespace.to_param,
           project_id: project.to_param,
@@ -68,6 +70,10 @@ describe Projects::BranchesController do
       let(:branch) { "1-feature-branch" }
       let!(:issue) { create(:issue, project: project) }
 
+      before do
+        sign_in(user)
+      end
+
       it 'redirects' do
         post :create,
           namespace_id: project.namespace.to_param,
@@ -94,6 +100,10 @@ describe Projects::BranchesController do
   describe "POST destroy with HTML format" do
     render_views
 
+    before do
+      sign_in(user)
+    end
+
     it 'returns 303' do
       post :destroy,
            format: :html,
@@ -109,6 +119,8 @@ describe Projects::BranchesController do
     render_views
 
     before do
+      sign_in(user)
+
       post :destroy,
            format: :js,
            id: branch,
@@ -139,4 +151,42 @@ describe Projects::BranchesController do
       it { expect(response).to have_http_status(404) }
     end
   end
+
+  describe "DELETE destroy_all_merged" do
+    def destroy_all_merged
+      delete :destroy_all_merged,
+             namespace_id: project.namespace.to_param,
+             project_id: project.to_param
+    end
+
+    context 'when user is allowed to push' do
+      before do
+        sign_in(user)
+      end
+
+      it 'redirects to branches' do
+        destroy_all_merged
+
+        expect(response).to redirect_to namespace_project_branches_path(project.namespace, project)
+      end
+
+      it 'starts worker to delete merged branches' do
+        expect_any_instance_of(DeleteMergedBranchesService).to receive(:async_execute)
+
+        destroy_all_merged
+      end
+    end
+
+    context 'when user is not allowed to push' do
+      before do
+        sign_in(developer)
+      end
+
+      it 'responds with status 404' do
+        destroy_all_merged
+
+        expect(response).to have_http_status(404)
+      end
+    end
+  end
 end
diff --git a/spec/requests/api/branches_spec.rb b/spec/requests/api/branches_spec.rb
index 1711096f4bd..8f605757186 100644
--- a/spec/requests/api/branches_spec.rb
+++ b/spec/requests/api/branches_spec.rb
@@ -299,4 +299,20 @@ describe API::API, api: true  do
       expect(json_response['message']).to eq('Cannot remove HEAD branch')
     end
   end
+
+  describe "DELETE /projects/:id/repository/merged_branches" do
+    before do
+      allow_any_instance_of(Repository).to receive(:rm_branch).and_return(true)
+    end
+
+    it 'returns 200' do
+      delete api("/projects/#{project.id}/repository/merged_branches", user)
+      expect(response).to have_http_status(200)
+    end
+
+    it 'returns a 403 error if guest' do
+      delete api("/projects/#{project.id}/repository/merged_branches", user2)
+      expect(response).to have_http_status(403)
+    end
+  end
 end
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
diff --git a/spec/workers/delete_merged_branches_worker_spec.rb b/spec/workers/delete_merged_branches_worker_spec.rb
new file mode 100644
index 00000000000..d9497bd486c
--- /dev/null
+++ b/spec/workers/delete_merged_branches_worker_spec.rb
@@ -0,0 +1,19 @@
+require 'spec_helper'
+
+describe DeleteMergedBranchesWorker do
+  subject(:worker) { described_class.new }
+
+  let(:project) { create(:project) }
+
+  describe "#perform" do
+    it "calls DeleteMergedBranchesService" do
+      expect_any_instance_of(DeleteMergedBranchesService).to receive(:execute).and_return(true)
+
+      worker.perform(project.id, project.owner.id)
+    end
+
+    it "returns false when project was not found" do
+      expect(worker.perform('unknown', project.owner.id)).to be_falsy
+    end
+  end
+end