1 files changed, 147 insertions, 0 deletions
diff --git a/spec/features/merge_requests/versions_spec.rb b/spec/features/merge_requests/versions_spec.rb
new file mode 100644
index 00000000000..68a68f5d3f3
--- /dev/null
+++ b/spec/features/merge_requests/versions_spec.rb
@@ -0,0 +1,147 @@
+require 'spec_helper'
+
+feature 'Merge Request versions', js: true, feature: true do
+  let(:merge_request) { create(:merge_request, importing: true) }
+  let(:project) { merge_request.source_project }
+  let!(:merge_request_diff1) { merge_request.merge_request_diffs.create(head_commit_sha: '6f6d7e7ed97bb5f0054f2b1df789b39ca89b6ff9') }
+  let!(:merge_request_diff2) { merge_request.merge_request_diffs.create(head_commit_sha: nil) }
+  let!(:merge_request_diff3) { merge_request.merge_request_diffs.create(head_commit_sha: '5937ac0a7beb003549fc5fd26fc247adbce4a52e') }
+
+  before do
+    login_as :admin
+    visit diffs_namespace_project_merge_request_path(project.namespace, project, merge_request)
+  end
+
+  it 'show the latest version of the diff' do
+    page.within '.mr-version-dropdown' do
+      expect(page).to have_content 'latest version'
+    end
+
+    expect(page).to have_content '8 changed files'
+  end
+
+  describe 'switch between versions' do
+    before do
+      page.within '.mr-version-dropdown' do
+        find('.btn-default').click
+        find(:link, 'version 1').trigger('click')
+      end
+    end
+
+    it 'should show older version' do
+      page.within '.mr-version-dropdown' do
+        expect(page).to have_content 'version 1'
+      end
+
+      expect(page).to have_content '5 changed files'
+    end
+
+    it 'show the message about disabled comment creation' do
+      expect(page).to have_content 'comment creation is disabled'
+    end
+
+    it 'shows comments that were last relevant at that version' do
+      position = Gitlab::Diff::Position.new(
+        old_path: ".gitmodules",
+        new_path: ".gitmodules",
+        old_line: nil,
+        new_line: 4,
+        diff_refs: merge_request_diff1.diff_refs
+      )
+      outdated_diff_note = create(:diff_note_on_merge_request, project: project, noteable: merge_request, position: position)
+      outdated_diff_note.position = outdated_diff_note.original_position
+      outdated_diff_note.save!
+
+      expect(page).to have_css(".diffs .notes[data-discussion-id='#{outdated_diff_note.discussion_id}']")
+    end
+  end
+
+  describe 'compare with older version' do
+    before do
+      page.within '.mr-version-compare-dropdown' do
+        find('.btn-default').click
+        find(:link, 'version 1').trigger('click')
+      end
+    end
+
+    it 'has a path with comparison context' do
+      expect(page).to have_current_path diffs_namespace_project_merge_request_path(
+        project.namespace,
+        project,
+        merge_request.iid,
+        diff_id: merge_request_diff3.id,
+        start_sha: '6f6d7e7ed97bb5f0054f2b1df789b39ca89b6ff9'
+      )
+    end
+
+    it 'should have correct value in the compare dropdown' do
+      page.within '.mr-version-compare-dropdown' do
+        expect(page).to have_content 'version 1'
+      end
+    end
+
+    it 'show the message about disabled comments' do
+      expect(page).to have_content 'Comments are disabled'
+    end
+
+    it 'show diff between new and old version' do
+      expect(page).to have_content '4 changed files with 15 additions and 6 deletions'
+    end
+
+    it 'should return to latest version when "Show latest version" button is clicked' do
+      click_link 'Show latest version'
+      page.within '.mr-version-dropdown' do
+        expect(page).to have_content 'latest version'
+      end
+      expect(page).to have_content '8 changed files'
+    end
+  end
+
+  describe 'compare with same version' do
+    before do
+      page.within '.mr-version-compare-dropdown' do
+        find('.btn-default').click
+        click_link 'version 1'
+      end
+    end
+
+    it 'should have 0 chages between versions' do
+      page.within '.mr-version-compare-dropdown' do
+        expect(page).to have_content 'version 1'
+      end
+
+      page.within '.mr-version-dropdown' do
+        find('.btn-default').click
+        find(:link, 'version 1').trigger('click')
+      end
+
+      expect(page).to have_content '0 changed files'
+    end
+  end
+
+  describe 'compare with newer version' do
+    before do
+      page.within '.mr-version-compare-dropdown' do
+        find('.btn-default').click
+        click_link 'version 2'
+      end
+    end
+
+    it 'should set the compared versions to be the same' do
+      page.within '.mr-version-compare-dropdown' do
+        expect(page).to have_content 'version 2'
+      end
+
+      page.within '.mr-version-dropdown' do
+        find('.btn-default').click
+        find(:link, 'version 1').trigger('click')
+      end
+
+      page.within '.mr-version-compare-dropdown' do
+        expect(page).to have_content 'version 1'
+      end
+
+      expect(page).to have_content '0 changed files'
+    end
+  end
+end