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.

app/assets/stylesheets/framework/buttons.scss

@@ -142,6 +142,10 @@
     &.btn-save {
       @include btn-outline($white-light, $green-normal, $green-normal, $green-light, $white-light, $green-light);
     }
+
+    &.btn-remove {
+      @include btn-outline($white-light, $red-normal, $red-normal, $red-light, $white-light, $red-light);
+    }
   }
   &.btn-gray {

app/controllers/projects/branches_controller.rb

@@ -4,7 +4,7 @@ class Projects::BranchesController < Projects::ApplicationController
   # Authorize
   before_action :require_non_empty_project
   before_action :authorize_download_code!
-  before_action :authorize_push_code!, only: [:new, :create, :destroy]
+  before_action :authorize_push_code!, only: [:new, :create, :destroy, :destroy_all_merged]
   def index
     @sort = params[:sort].presence || sort_value_name
@@ -62,6 +62,13 @@ class Projects::BranchesController < Projects::ApplicationController
     end
   end
+  def destroy_all_merged
+    DeleteMergedBranchesService.new(@project, current_user).async_execute
+
+    redirect_to namespace_project_branches_path(@project.namespace, @project),
+      notice: 'Merged branches are being deleted. This can take some time depending on the number of branches. Please refresh the page to see changes.'
+  end
+
   private
   def ref

app/services/delete_merged_branches_service.rb

+require_relative 'base_service'
+
+class DeleteMergedBranchesService < BaseService
+  def async_execute
+    DeleteMergedBranchesWorker.perform_async(project.id, current_user.id)
+  end
+
+  def execute
+    raise Gitlab::Access::AccessDeniedError unless can?(current_user, :push_code, project)
+
+    branches = project.repository.branch_names
+    branches = branches.select { |branch| project.repository.merged_to_root_ref?(branch) }
+
+    branches.each do |branch|
+      DeleteBranchService.new(project, current_user).execute(branch)
+    end
+  end
+end

app/views/projects/branches/index.html.haml

@@ -26,6 +26,8 @@
               = sort_title_oldest_updated
       - if can? current_user, :push_code, @project
+        = link_to namespace_project_merged_branches_path(@project.namespace, @project), class: 'btn btn-inverted btn-remove has-tooltip', title: "Delete all branches that are merged into '#{@project.repository.root_ref}'", method: :delete, data: { confirm: "Deleting the merged branches cannot be undone. Are you sure?", container: 'body' } do
+          Delete merged branches
         = link_to new_namespace_project_branch_path(@project.namespace, @project), class: 'btn btn-create' do
           New branch

app/workers/delete_merged_branches_worker.rb

+class DeleteMergedBranchesWorker
+  include Sidekiq::Worker
+  include DedicatedSidekiqQueue
+
+  def perform(project_id, user_id)
+    begin
+      project = Project.find(project_id)
+    rescue ActiveRecord::RecordNotFound
+      return
+    end
+
+    user = User.find(user_id)
+
+    begin
+      DeleteMergedBranchesService.new(project, user).execute
+    rescue Gitlab::Access::AccessDeniedError
+      return
+    end
+  end
+end

changelogs/unreleased/21076-deleted-merged-branches.yml

+---
+title: Add button to delete all merged branches
+merge_request: 6449
+author: Toon Claes

config/routes/project.rb

@@ -300,6 +300,7 @@ resources :namespaces, path: '/', constraints: { id: /[a-zA-Z.0-9_\-]+/ }, only:
       end
       resources :branches, only: [:index, :new, :create, :destroy], constraints: { id: Gitlab::Regex.git_reference_regex }
+      delete :merged_branches, controller: 'branches', action: :destroy_all_merged
       resources :tags, only: [:index, :show, :new, :create, :destroy], constraints: { id: Gitlab::Regex.git_reference_regex } do
         resource :release, only: [:edit, :update]
       end

config/sidekiq_queues.yml

@@ -33,6 +33,7 @@
   - [project_service, 1]
   - [clear_database_cache, 1]
   - [delete_user, 1]
+  - [delete_merged_branches, 1]
   - [expire_build_instance_artifacts, 1]
   - [group_destroy, 1]
   - [irker, 1]

doc/api/branches.md

@@ -240,3 +240,21 @@ Example response:
   "branch_name": "newbranch"
 }
 ```
+
+## Delete merged branches
+
+Will delete all branches that are merged into the project's default branch.
+
+```
+DELETE /projects/:id/repository/merged_branches
+```
+
+| Attribute | Type | Required | Description |
+| --------- | ---- | -------- | ----------- |
+| `id`      | integer | yes | The ID of a project |
+
+It returns `200` to indicate deletion of all merged branches was started.
+
+```bash
+curl --request DELETE --header "PRIVATE-TOKEN: 9koXpg98eAheJpvBs5tK" "https://gitlab.example.com/api/v3/projects/5/repository/merged_branches"
+```

lib/api/branches.rb

@@ -128,6 +128,18 @@ module API
           render_api_error!(result[:message], result[:return_code])
         end
       end
+
+      # Delete all merged branches
+      #
+      # Parameters:
+      #   id (required) - The ID of a project
+      # Example Request:
+      #   DELETE /projects/:id/repository/branches/delete_merged
+      delete ":id/repository/merged_branches" do
+        DeleteMergedBranchesService.new(user_project, current_user).async_execute
+
+        status(200)
+      end
     end
   end
 end

spec/controllers/projects/branches_controller_spec.rb

 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

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

spec/services/delete_merged_branches_service_spec.rb

+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

spec/workers/delete_merged_branches_worker_spec.rb

+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