path: root/spec/services/merge_requests/merge_service_spec.rb

# frozen_string_literal: true

require 'spec_helper'

RSpec.describe MergeRequests::MergeService, feature_category: :code_review_workflow do
  include ExclusiveLeaseHelpers

  let_it_be(:user) { create(:user) }
  let_it_be(:user2) { create(:user) }

  where(:ff_refactor_merge_service_enabled) { [true, false] }

  with_them do
    let(:merge_request) { create(:merge_request, :simple, author: user2, assignees: [user2]) }
    let(:project) { merge_request.project }

    before do
      stub_feature_flags(refactor_merge_service: ff_refactor_merge_service_enabled)

      project.add_maintainer(user)
      project.add_developer(user2)
    end

    describe '#execute' do
      let(:service) { described_class.new(project: project, current_user: user, params: merge_params) }
      let(:merge_params) do
        { commit_message: 'Awesome message', sha: merge_request.diff_head_sha }
      end

      let(:lease_key) { "merge_requests_merge_service:#{merge_request.id}" }
      let!(:lease) { stub_exclusive_lease(lease_key) }

      shared_examples 'with valid params' do
        before do
          allow(service).to receive(:execute_hooks)
          expect(merge_request).to receive(:update_and_mark_in_progress_merge_commit_sha).twice.and_call_original

          perform_enqueued_jobs do
            service.execute(merge_request)
          end
        end

        it { expect(merge_request).to be_valid }
        it { expect(merge_request).to be_merged }

        it 'does not update squash_commit_sha if it is not a squash' do
          expect(merge_request.squash_commit_sha).to be_nil
        end

        it 'sends email to user2 about merge of new merge_request' do
          email = ActionMailer::Base.deliveries.last
          expect(email.to.first).to eq(user2.email)
          expect(email.subject).to include(merge_request.title)
        end

        context 'note creation' do
          it 'creates resource state event about merge_request merge' do
            event = merge_request.resource_state_events.last
            expect(event.state).to eq('merged')
          end
        end
      end

      shared_examples 'squashing' do
        # A merge request with 5 commits
        let(:merge_request) do
          create(
            :merge_request,
            :simple,
            author: user2,
            assignees: [user2],
            squash: true,
            source_branch: 'improve/awesome',
            target_branch: 'fix'
          )
        end

        let(:merge_params) do
          { commit_message: 'Merge commit message',
            squash_commit_message: 'Squash commit message',
            sha: merge_request.diff_head_sha }
        end

        before do
          allow(service).to receive(:execute_hooks)
          expect(merge_request).to receive(:update_and_mark_in_progress_merge_commit_sha).twice.and_call_original

          perform_enqueued_jobs do
            service.execute(merge_request)
          end
        end

        it 'merges the merge request with squashed commits' do
          expect(merge_request).to be_merged

          merge_commit = merge_request.merge_commit
          squash_commit = merge_request.merge_commit.parents.last

          expect(merge_commit.message).to eq('Merge commit message')
          expect(squash_commit.message).to eq("Squash commit message\n")
        end

        it 'persists squash_commit_sha' do
          squash_commit = merge_request.merge_commit.parents.last

          expect(merge_request.squash_commit_sha).to eq(squash_commit.id)
        end
      end

      context 'when merge strategy is merge commit' do
        it 'persists merge_commit_sha and nullifies in_progress_merge_commit_sha' do
          service.execute(merge_request)

          expect(merge_request.merge_commit_sha).not_to be_nil
          expect(merge_request.in_progress_merge_commit_sha).to be_nil
        end

        it_behaves_like 'with valid params'

        it_behaves_like 'squashing'
      end

      context 'when merge strategy is fast forward' do
        before do
          project.update!(merge_requests_ff_only_enabled: true)
        end

        let(:merge_request) do
          create(
            :merge_request,
            source_branch: 'flatten-dir',
            target_branch: 'improve/awesome',
            assignees: [user2],
            author: create(:user)
          )
        end

        it 'does not create merge_commit_sha and nullifies in_progress_merge_commit_sha' do
          service.execute(merge_request)

          expect(merge_request.merge_commit_sha).to be_nil
          expect(merge_request.in_progress_merge_commit_sha).to be_nil
        end

        it_behaves_like 'with valid params'

        it 'updates squash_commit_sha if it is a squash' do
          expect(merge_request).to receive(:update_and_mark_in_progress_merge_commit_sha).twice.and_call_original

          merge_request.update!(squash: true)

          expect { service.execute(merge_request) }
            .to change { merge_request.squash_commit_sha }
                  .from(nil)

          expect(merge_request.merge_commit_sha).to be_nil
          expect(merge_request.in_progress_merge_commit_sha).to be_nil
        end
      end

      context 'running the service once' do
        let(:ref) { merge_request.to_reference(full: true) }
        let(:jid) { SecureRandom.hex }

        let(:messages) do
          [
            /#{ref} - Git merge started on JID #{jid}/,
            /#{ref} - Git merge finished on JID #{jid}/,
            /#{ref} - Post merge started on JID #{jid}/,
            /#{ref} - Post merge finished on JID #{jid}/,
            /#{ref} - Merge process finished on JID #{jid}/
          ]
        end

        before do
          merge_request.update!(merge_jid: jid)
          ::Gitlab::ApplicationContext.push(caller_id: 'MergeWorker')
        end

        it 'logs status messages' do
          allow(Gitlab::AppLogger).to receive(:info).and_call_original

          messages.each do |message|
            expect(Gitlab::AppLogger).to receive(:info).with(
              hash_including(
                'meta.caller_id' => 'MergeWorker',
                message: message,
                merge_request_info: ref
              )
            ).and_call_original
          end

          service.execute(merge_request)
        end
      end

      context 'running the service multiple time' do
        it 'is idempotent' do
          2.times { service.execute(merge_request) }

          expect(merge_request.merge_error).to be_falsey
          expect(merge_request).to be_valid
          expect(merge_request).to be_merged

          commit_messages = project.repository.commits('master', limit: 2).map(&:message)
          expect(commit_messages.uniq.size).to eq(2)
          expect(merge_request.in_progress_merge_commit_sha).to be_nil
        end
      end

      context 'when an invalid sha is passed' do
        let(:merge_request) do
          create(
            :merge_request,
            :simple,
            author: user2,
            assignees: [user2],
            squash: true,
            source_branch: 'improve/awesome',
            target_branch: 'fix'
          )
        end

        let(:merge_params) do
          { sha: merge_request.commits.second.sha }
        end

        it 'does not merge the MR' do
          service.execute(merge_request)

          expect(merge_request).not_to be_merged
          expect(merge_request.merge_error).to match(/Branch has been updated/)
        end
      end

      context 'when the `sha` param is missing' do
        let(:merge_params) { {} }

        it 'returns the error' do
          merge_error = 'Branch has been updated since the merge was requested. '\
                        'Please review the changes.'

          expect { service.execute(merge_request) }
            .to change { merge_request.merge_error }
                  .from(nil).to(merge_error)
        end
      end

      context 'closes related issues' do
        before do
          allow(project).to receive(:default_branch).and_return(merge_request.target_branch)
        end

        it 'closes GitLab issue tracker issues', :sidekiq_inline do
          issue  = create :issue, project: project
          commit = double('commit', safe_message: "Fixes #{issue.to_reference}", date: Time.current, authored_date: Time.current)
          allow(merge_request).to receive(:commits).and_return([commit])
          merge_request.cache_merge_request_closes_issues!

          service.execute(merge_request)

          expect(issue.reload.closed?).to be_truthy
        end

        context 'with Jira integration' do
          include JiraIntegrationHelpers

          let(:jira_tracker) { project.create_jira_integration }
          let(:jira_issue)   { ExternalIssue.new('JIRA-123', project) }
          let(:commit)       { double('commit', safe_message: "Fixes #{jira_issue.to_reference}") }

          before do
            stub_jira_integration_test
            project.update!(has_external_issue_tracker: true)
            jira_integration_settings
            stub_jira_urls(jira_issue.id)
            allow(merge_request).to receive(:commits).and_return([commit])
          end

          it 'closes issues on Jira issue tracker' do
            jira_issue = ExternalIssue.new('JIRA-123', project)
            stub_jira_urls(jira_issue)
            commit = double('commit', safe_message: "Fixes #{jira_issue.to_reference}")
            allow(merge_request).to receive(:commits).and_return([commit])

            expect_any_instance_of(Integrations::Jira).to receive(:close_issue).with(merge_request, jira_issue, user).once

            service.execute(merge_request)
          end

          context 'wrong issue markdown' do
            it 'does not close issues on Jira issue tracker' do
              jira_issue = ExternalIssue.new('#JIRA-123', project)
              stub_jira_urls(jira_issue)
              commit = double('commit', safe_message: "Fixes #{jira_issue.to_reference}")
              allow(merge_request).to receive(:commits).and_return([commit])

              expect_any_instance_of(Integrations::Jira).not_to receive(:close_issue)

              service.execute(merge_request)
            end
          end
        end
      end

      context 'closes related todos' do
        let(:merge_request) { create(:merge_request, assignees: [user], author: user) }
        let(:project) { merge_request.project }

        let!(:todo) do
          create(:todo, :assigned,
            project: project,
            author: user,
            user: user,
            target: merge_request)
        end

        before do
          allow(service).to receive(:execute_hooks)

          perform_enqueued_jobs do
            service.execute(merge_request)
            todo.reload
          end
        end

        it { expect(todo).to be_done }
      end

      context 'source branch removal' do
        context 'when the source branch is protected' do
          let(:service) do
            described_class.new(project: project, current_user: user, params: merge_params.merge('should_remove_source_branch' => true))
          end

          before do
            create(:protected_branch, project: project, name: merge_request.source_branch)
          end

          it 'does not delete the source branch' do
            expect(::Branches::DeleteService).not_to receive(:new)

            service.execute(merge_request)
          end
        end

        context 'when the source branch is the default branch' do
          let(:service) do
            described_class.new(project: project, current_user: user, params: merge_params.merge('should_remove_source_branch' => true))
          end

          before do
            allow(project).to receive(:root_ref?).with(merge_request.source_branch).and_return(true)
          end

          it 'does not delete the source branch' do
            expect(::Branches::DeleteService).not_to receive(:new)
            service.execute(merge_request)
          end
        end

        context 'when the source branch can be removed' do
          context 'when MR author set the source branch to be removed' do
            before do
              merge_request.update_attribute(:merge_params, { 'force_remove_source_branch' => '1' })
            end

            # Not a real use case. When a merger merges a MR , merge param 'should_remove_source_branch' is defined
            it 'removes the source branch using the author user' do
              expect(::MergeRequests::DeleteSourceBranchWorker).to receive(:perform_async).with(merge_request.id, merge_request.source_branch_sha, merge_request.author.id)

              service.execute(merge_request)

              expect(merge_request.reload.should_remove_source_branch?).to be nil
            end

            context 'when the merger set the source branch not to be removed' do
              let(:service) { described_class.new(project: project, current_user: user, params: merge_params.merge('should_remove_source_branch' => false)) }

              it 'does not delete the source branch' do
                expect(::MergeRequests::DeleteSourceBranchWorker).not_to receive(:perform_async)

                service.execute(merge_request)

                expect(merge_request.reload.should_remove_source_branch?).to be false
              end
            end
          end

          context 'when MR merger set the source branch to be removed' do
            let(:service) do
              described_class.new(project: project, current_user: user, params: merge_params.merge('should_remove_source_branch' => true))
            end

            it 'removes the source branch using the current user' do
              expect(::MergeRequests::DeleteSourceBranchWorker).to receive(:perform_async).with(merge_request.id, merge_request.source_branch_sha, user.id)

              service.execute(merge_request)

              expect(merge_request.reload.should_remove_source_branch?).to be true
            end
          end
        end
      end

      context 'error handling' do
        before do
          allow(Gitlab::AppLogger).to receive(:error)
        end

        context 'when source is missing' do
          it 'logs and saves error' do
            allow(merge_request).to receive(:diff_head_sha) { nil }

            error_message = 'No source for merge'

            service.execute(merge_request)

            expect(merge_request.merge_error).to eq(error_message)
            expect(Gitlab::AppLogger).to have_received(:error).with(
              hash_including(
                merge_request_info: merge_request.to_reference(full: true),
                message: a_string_matching(error_message)
              )
            )
          end
        end

        it 'logs and saves error if there is an exception' do
          error_message = 'error message'

          allow_next_instance_of(MergeRequests::MergeStrategies::FromSourceBranch) do |strategy|
            allow(strategy).to receive(:execute_git_merge!).and_raise(error_message)
          end
          # we can remove these allows upon refactor_merge_service cleanup
          allow(service).to receive(:repository).and_raise(error_message)
          allow(service).to receive(:execute_hooks)

          service.execute(merge_request)

          expect(merge_request.merge_error).to eq(described_class::GENERIC_ERROR_MESSAGE)
          expect(Gitlab::AppLogger).to have_received(:error).with(
            hash_including(
              merge_request_info: merge_request.to_reference(full: true),
              message: a_string_matching(error_message)
            )
          )
        end

        it 'logs and saves error if user is not authorized' do
          stub_exclusive_lease

          unauthorized_user = create(:user)
          project.add_reporter(unauthorized_user)

          service = described_class.new(project: project, current_user: unauthorized_user)

          service.execute(merge_request)

          expect(merge_request.merge_error)
            .to eq('You are not allowed to merge this merge request')
        end

        it 'logs and saves error if there is an PreReceiveError exception' do
          error_message = 'error message'

          allow_next_instance_of(MergeRequests::MergeStrategies::FromSourceBranch) do |strategy|
            allow(strategy).to receive(:execute_git_merge!).and_raise(Gitlab::Git::PreReceiveError, "GitLab: #{error_message}")
          end
          # we can remove these allows upon refactor_merge_service cleanup
          allow(service).to receive(:repository).and_raise(Gitlab::Git::PreReceiveError, "GitLab: #{error_message}")
          allow(service).to receive(:execute_hooks)

          service.execute(merge_request)

          expect(merge_request.merge_error).to include('Something went wrong during merge pre-receive hook')
          expect(Gitlab::AppLogger).to have_received(:error).with(
            hash_including(
              merge_request_info: merge_request.to_reference(full: true),
              message: a_string_matching(error_message)
            )
          )
        end

        it 'logs and saves error if commit is not created' do
          allow_any_instance_of(Repository).to receive(:merge).and_return(false)
          allow(service).to receive(:execute_hooks)

          service.execute(merge_request)

          expect(merge_request).to be_open
          expect(merge_request.merge_commit_sha).to be_nil
          expect(merge_request.merge_error).to include(described_class::GENERIC_ERROR_MESSAGE)
          expect(Gitlab::AppLogger).to have_received(:error).with(
            hash_including(
              merge_request_info: merge_request.to_reference(full: true),
              message: a_string_matching(described_class::GENERIC_ERROR_MESSAGE)
            )
          )
        end

        context 'when squashing is required' do
          before do
            merge_request.update!(source_branch: 'master', target_branch: 'feature')
            merge_request.target_project.project_setting.squash_always!
          end

          it 'raises an error if squashing is not done' do
            error_message = 'requires squashing commits'

            service.execute(merge_request)

            expect(merge_request).to be_open

            expect(merge_request.merge_commit_sha).to be_nil
            expect(merge_request.squash_commit_sha).to be_nil
            expect(merge_request.merge_error).to include(error_message)
            expect(Gitlab::AppLogger).to have_received(:error).with(
              hash_including(
                merge_request_info: merge_request.to_reference(full: true),
                message: a_string_matching(error_message)
              )
            )
          end
        end

        context 'when squashing' do
          before do
            merge_request.update!(source_branch: 'master', target_branch: 'feature')
          end

          it 'logs and saves error if there is an error when squashing' do
            error_message = 'Squashing failed: Squash the commits locally, resolve any conflicts, then push the branch.'

            allow_any_instance_of(MergeRequests::SquashService).to receive(:squash!).and_return(nil)
            merge_request.update!(squash: true)

            service.execute(merge_request)

            expect(merge_request).to be_open
            expect(merge_request.merge_commit_sha).to be_nil
            expect(merge_request.squash_commit_sha).to be_nil
            expect(merge_request.merge_error).to include(error_message)
            expect(Gitlab::AppLogger).to have_received(:error).with(
              hash_including(
                merge_request_info: merge_request.to_reference(full: true),
                message: a_string_matching(error_message)
              )
            )
          end

          it 'logs and saves error if there is an PreReceiveError exception' do
            error_message = 'error message'

            allow_next_instance_of(MergeRequests::MergeStrategies::FromSourceBranch) do |strategy|
              allow(strategy).to receive(:execute_git_merge!).and_raise(Gitlab::Git::PreReceiveError, "GitLab: #{error_message}")
            end
            # we can remove these allows upon refactor_merge_service cleanup
            allow(service).to receive(:repository).and_raise(Gitlab::Git::PreReceiveError, "GitLab: #{error_message}")
            allow(service).to receive(:execute_hooks)
            merge_request.update!(squash: true)

            service.execute(merge_request)

            expect(merge_request).to be_open
            expect(merge_request.merge_commit_sha).to be_nil
            expect(merge_request.squash_commit_sha).to be_nil
            expect(merge_request.merge_error).to include('Something went wrong during merge pre-receive hook')
            expect(Gitlab::AppLogger).to have_received(:error).with(
              hash_including(
                merge_request_info: merge_request.to_reference(full: true),
                message: a_string_matching(error_message)
              )
            )
          end

          context 'when fast-forward merge is not allowed' do
            before do
              allow_any_instance_of(Repository).to receive(:ancestor?).and_return(nil)
            end

            %w(semi-linear ff).each do |merge_method|
              it "logs and saves error if merge is #{merge_method} only" do
                merge_method = 'rebase_merge' if merge_method == 'semi-linear'
                merge_request.project.update!(merge_method: merge_method)
                error_message = 'Only fast-forward merge is allowed for your project. Please update your source branch'
                allow(service).to receive(:execute_hooks)
                expect(lease).to receive(:cancel)

                service.execute(merge_request)

                expect(merge_request).to be_open
                expect(merge_request.merge_commit_sha).to be_nil
                expect(merge_request.squash_commit_sha).to be_nil
                expect(merge_request.merge_error).to include(error_message)
                expect(Gitlab::AppLogger).to have_received(:error).with(
                  hash_including(
                    merge_request_info: merge_request.to_reference(full: true),
                    message: a_string_matching(error_message)
                  )
                )
              end
            end
          end
        end

        context 'when not mergeable' do
          let!(:error_message) { 'Merge request is not mergeable' }

          context 'with failing CI' do
            before do
              allow(merge_request).to receive(:mergeable_ci_state?) { false }
            end

            it 'logs and saves error' do
              service.execute(merge_request)

              expect(Gitlab::AppLogger).to have_received(:error).with(
                hash_including(
                  merge_request_info: merge_request.to_reference(full: true),
                  message: a_string_matching(error_message)
                )
              )
            end
          end

          context 'with unresolved discussions' do
            before do
              allow(merge_request).to receive(:mergeable_discussions_state?) { false }
            end

            it 'logs and saves error' do
              service.execute(merge_request)

              expect(Gitlab::AppLogger).to have_received(:error).with(
                hash_including(
                  merge_request_info: merge_request.to_reference(full: true),
                  message: a_string_matching(error_message)
                )
              )
            end

            context 'when passing `skip_discussions_check: true` as `options` parameter' do
              it 'merges the merge request' do
                service.execute(merge_request, skip_discussions_check: true)

                expect(merge_request).to be_valid
                expect(merge_request).to be_merged
              end
            end
          end
        end

        context 'when passing `check_mergeability_retry_lease: true` as `options` parameter' do
          it 'call mergeable? with check_mergeability_retry_lease' do
            expect(merge_request).to receive(:mergeable?).with(hash_including(check_mergeability_retry_lease: true)).and_call_original

            service.execute(merge_request, check_mergeability_retry_lease: true)
          end
        end
      end

      context 'when the other sidekiq worker has already been running' do
        before do
          stub_exclusive_lease_taken(lease_key)
        end

        it 'does not execute service' do
          expect(service).not_to receive(:commit)

          service.execute(merge_request)
        end
      end
    end
  end
end