Allows MR authors to have the source branch removed when merging the MR

CHANGELOG

@@ -65,6 +65,7 @@ v 8.8.0 (unreleased)
   - All Grape API helpers are now instrumented
   - Improve Issue formatting for the Slack Service (Jeroen van Baarsen)
   - Fixed advice on invalid permissions on upload path !2948 (Ludovic Perrine)
+  - Allows MR authors to have the source branch removed when merging the MR. !2801 (Jeroen Jacobs)
 
 v 8.7.6
   - Fix links on wiki pages for relative url setups. !4131 (Artem Sidorenko)

app/controllers/projects/merge_requests_controller.rb

@@ -334,7 +334,8 @@ class Projects::MergeRequestsController < Projects::ApplicationController
     params.require(:merge_request).permit(
       :title, :assignee_id, :source_project_id, :source_branch,
       :target_project_id, :target_branch, :milestone_id,
-      :state_event, :description, :task_num, label_ids: []
+      :state_event, :description, :task_num, :force_remove_source_branch,
+      label_ids: []
     )
   end
 

app/models/merge_request.rb

@@ -286,6 +286,18 @@ class MergeRequest < ActiveRecord::Base
       last_commit == source_project.commit(source_branch)
   end
 
+  def should_remove_source_branch?
+    merge_params['should_remove_source_branch'].present?
+  end
+
+  def force_remove_source_branch?
+    merge_params['force_remove_source_branch'].present?
+  end
+
+  def remove_source_branch?
+    should_remove_source_branch? || force_remove_source_branch?
+  end
+
   def mr_and_commit_notes
     # Fetch comments only from last 100 commits
     commits_for_notes_limit = 100
@@ -426,7 +438,10 @@ class MergeRequest < ActiveRecord::Base
 
     self.merge_when_build_succeeds = false
     self.merge_user = nil
-    self.merge_params = nil
+    if merge_params
+      merge_params.delete('should_remove_source_branch')
+      merge_params.delete('commit_message')
+    end
 
     self.save
   end

app/services/merge_requests/create_service.rb

@@ -8,11 +8,14 @@ module MergeRequests
       @project = Project.find(params[:target_project_id]) if params[:target_project_id]
 
       filter_params
-      label_params = params[:label_ids]
-      merge_request = MergeRequest.new(params.except(:label_ids))
+      label_params = params.delete(:label_ids)
+      force_remove_source_branch = params.delete(:force_remove_source_branch)
+
+      merge_request = MergeRequest.new(params)
       merge_request.source_project = source_project
       merge_request.target_project ||= source_project
       merge_request.author = current_user
+      merge_request.merge_params['force_remove_source_branch'] = force_remove_source_branch
 
       if merge_request.save
         merge_request.update_attributes(label_ids: label_params)

app/services/merge_requests/merge_service.rb

@@ -45,10 +45,14 @@ module MergeRequests
     def after_merge
       MergeRequests::PostMergeService.new(project, current_user).execute(merge_request)
 
-      if params[:should_remove_source_branch].present?
-        DeleteBranchService.new(@merge_request.source_project, current_user).
+      if params[:should_remove_source_branch].present? || @merge_request.force_remove_source_branch?
+        DeleteBranchService.new(@merge_request.source_project, branch_deletion_user).
           execute(merge_request.source_branch)
       end
     end
+
+    def branch_deletion_user
+      @merge_request.force_remove_source_branch? ? @merge_request.author : current_user
+    end
   end
 end

app/services/merge_requests/update_service.rb

@@ -11,6 +11,8 @@ module MergeRequests
       params.except!(:target_project_id)
       params.except!(:source_branch)
 
+      merge_request.merge_params['force_remove_source_branch'] = params.delete(:force_remove_source_branch)
+
       update(merge_request)
     end
 

app/views/projects/merge_requests/widget/open/_accept.html.haml

@@ -25,7 +25,10 @@
         - else
           = f.button class: "btn btn-create btn-grouped js-merge-button accept_merge_request #{status_class}" do
             Accept Merge Request
-      - if @merge_request.can_remove_source_branch?(current_user)
+      - if @merge_request.force_remove_source_branch?
+        .accept-control
+          The source branch will be removed.
+      - elsif @merge_request.can_remove_source_branch?(current_user)
         .accept-control.checkbox
           = label_tag :should_remove_source_branch, class: "remove_source_checkbox" do
             = check_box_tag :should_remove_source_branch

app/views/projects/merge_requests/widget/open/_merge_when_build_succeeds.html.haml

@@ -2,17 +2,16 @@
   Set by #{link_to_member(@project, @merge_request.merge_user, avatar: true)}
   to be merged automatically when the build succeeds.
 %div
-  - should_remove_source_branch = @merge_request.merge_params["should_remove_source_branch"].present?
   %p
     = succeed '.' do
       The changes will be merged into
       %span.label-branch= @merge_request.target_branch
-    - if should_remove_source_branch
+    - if @merge_request.remove_source_branch?
       The source branch will be removed.
     - else
       The source branch will not be removed.
 
-  - remove_source_branch_button = @merge_request.can_remove_source_branch?(current_user) && !should_remove_source_branch && @merge_request.merge_user == current_user
+  - remove_source_branch_button = !@merge_request.remove_source_branch? && @merge_request.can_remove_source_branch?(current_user) && @merge_request.merge_user == current_user
   - user_can_cancel_automatic_merge = @merge_request.can_cancel_merge_when_build_succeeds?(current_user)
   - if remove_source_branch_button || user_can_cancel_automatic_merge
     .clearfix.prepend-top-10

app/views/projects/merge_requests/widget/open/_not_allowed.html.haml

-%h4 
+%h4
   Ready to be merged automatically
 %p
   Ask someone with write access to this repository to merge this request.
+  - if @merge_request.force_remove_source_branch?
+    The source branch will be removed.

app/views/shared/issuable/_form.html.haml

@@ -114,6 +114,13 @@
       - if @merge_request.new_record?
          
         = link_to 'Change branches', mr_change_branches_path(@merge_request)
+  - if @merge_request.can_remove_source_branch?(current_user)
+    .form-group
+      .col-sm-10.col-sm-offset-2
+        .checkbox
+          = label_tag 'merge_request[force_remove_source_branch]' do
+            = check_box_tag 'merge_request[force_remove_source_branch]', '1', @merge_request.force_remove_source_branch?
+            Remove source branch when merge request is accepted.
 
 - is_footer = !(issuable.is_a?(MergeRequest) && issuable.new_record?)
 .row-content-block{class: (is_footer ? "footer-block" : "middle-block")}

spec/models/merge_request_spec.rb

@@ -260,13 +260,18 @@ describe MergeRequest, models: true do
   end
 
   describe "#reset_merge_when_build_succeeds" do
-    let(:merge_if_green) { create :merge_request, merge_when_build_succeeds: true, merge_user: create(:user) }
+    let(:merge_if_green) do
+      create :merge_request, merge_when_build_succeeds: true, merge_user: create(:user),
+                             merge_params: { "should_remove_source_branch" => "1", "commit_message" => "msg" }
+    end
 
     it "sets the item to false" do
       merge_if_green.reset_merge_when_build_succeeds
       merge_if_green.reload
 
       expect(merge_if_green.merge_when_build_succeeds).to be_falsey
+      expect(merge_if_green.merge_params["should_remove_source_branch"]).to be_nil
+      expect(merge_if_green.merge_params["commit_message"]).to be_nil
     end
   end
 

spec/services/merge_requests/create_service_spec.rb

@@ -12,7 +12,8 @@ describe MergeRequests::CreateService, services: true do
           title: 'Awesome merge_request',
           description: 'please fix',
           source_branch: 'feature',
-          target_branch: 'master'
+          target_branch: 'master',
+          force_remove_source_branch: '1'
         }
       end
 
@@ -29,6 +30,7 @@ describe MergeRequests::CreateService, services: true do
       it { expect(@merge_request).to be_valid }
       it { expect(@merge_request.title).to eq('Awesome merge_request') }
       it { expect(@merge_request.assignee).to be_nil }
+      it { expect(@merge_request.merge_params['force_remove_source_branch']).to eq('1') }
 
       it 'should execute hooks with default action' do
         expect(service).to have_received(:execute_hooks).with(@merge_request)

spec/services/merge_requests/merge_service_spec.rb

@@ -38,6 +38,21 @@ describe MergeRequests::MergeService, services: true do
       end
     end
 
+    context 'remove source branch by author' do
+      let(:service) do
+        merge_request.merge_params['force_remove_source_branch'] = '1'
+        merge_request.save!
+        MergeRequests::MergeService.new(project, user, commit_message: 'Awesome message')
+      end
+
+      it 'removes the source branch' do
+        expect(DeleteBranchService).to receive(:new).
+          with(merge_request.source_project, merge_request.author).
+          and_call_original
+        service.execute(merge_request)
+      end
+    end
+
     context "error handling" do
       let(:service) { MergeRequests::MergeService.new(project, user, commit_message: 'Awesome message') }
 

spec/services/merge_requests/update_service_spec.rb

@@ -39,7 +39,8 @@ describe MergeRequests::UpdateService, services: true do
           assignee_id: user2.id,
           state_event: 'close',
           label_ids: [label.id],
-          target_branch: 'target'
+          target_branch: 'target',
+          force_remove_source_branch: '1'
         }
       end
 
@@ -61,6 +62,7 @@ describe MergeRequests::UpdateService, services: true do
       it { expect(@merge_request.labels.count).to eq(1) }
       it { expect(@merge_request.labels.first.title).to eq(label.name) }
       it { expect(@merge_request.target_branch).to eq('target') }
+      it { expect(@merge_request.merge_params['force_remove_source_branch']).to eq('1') }
 
       it 'should execute hooks with update action' do
         expect(service).to have_received(:execute_hooks).