Merge branch '24507_remove_deleted_branch_link_in_merge_request' into 'master'

Remove unnecessary target branch link from MR page in case of deleted target branch

Fixes #24507

See merge request !7916

app/views/projects/merge_requests/_show.html.haml

@@ -31,7 +31,7 @@
         %span.label-branch= source_branch_with_namespace(@merge_request)
         %span into
         %span.label-branch
-          = link_to @merge_request.target_branch, namespace_project_commits_path(@project.namespace, @project, @merge_request.target_branch)
+          = link_to_if @merge_request.target_branch_exists?, @merge_request.target_branch, namespace_project_commits_path(@project.namespace, @project, @merge_request.target_branch)
         - if @merge_request.open? && @merge_request.diverged_from_target_branch?
           %span (#{pluralize(@merge_request.diverged_commits_count, 'commit')} behind)

changelogs/unreleased/24507_remove_deleted_branch_link_in_merge_request.yml

+---
+title: 'Remove unnecessary target branch link from MR page in case of deleted target branch'
+merge_request: 7916
+author: Rydkin Maxim

spec/features/merge_requests/target_branch_spec.rb

+require 'spec_helper'
+
+describe 'Target branch', feature: true do
+  let(:user) { create(:user) }
+  let(:merge_request) { create(:merge_request) }
+  let(:project) { merge_request.project }
+
+  def path_to_merge_request
+    namespace_project_merge_request_path(
+      project.namespace,
+      project, merge_request
+    )
+  end
+
+  before do
+    login_as user
+    project.team << [user, :master]
+  end
+
+  it 'shows link to target branch' do
+    visit path_to_merge_request
+    expect(page).to have_link('feature', href: namespace_project_commits_path(project.namespace, project, merge_request.target_branch))
+  end
+
+  context 'when branch was deleted' do
+    before do
+      DeleteBranchService.new(project, user).execute('feature')
+      visit path_to_merge_request
+    end
+
+    it 'shows a message about missing target branch' do
+      expect(page).to have_content(
+        'Target branch feature does not exist'
+      )
+    end
+
+    it 'does not show link to target branch' do
+      expect(page).not_to have_link('feature')
+    end
+  end
+end