add feature specs to test toggling of merge commit message between message with…

spec/features/merge_requests/closes_issues_spec.rb

 require 'spec_helper'
 
-feature 'Merge Commit Description', feature: true do
+feature 'Merge Request closing issues message', feature: true do
   let(:user) { create(:user) }
   let(:project) { create(:project, :public) }
   let(:issue_1) { create(:issue, project: project)}
@@ -21,8 +21,6 @@ feature 'Merge Commit Description', feature: true do
     login_as user
 
     visit namespace_project_merge_request_path(project.namespace, project, merge_request)
-
-    click_link 'Modify commit message'
   end
 
   context 'not closing or mentioning any issue' do

spec/features/merge_requests/merge_commit_message_toggle_spec.rb

+require 'spec_helper'
+
+feature 'Clicking toggle commit message link', feature: true, js: true do
+  let(:user) { create(:user) }
+  let(:project) { create(:project, :public) }
+  let(:issue_1) { create(:issue, project: project)}
+  let(:issue_2) { create(:issue, project: project)}
+  let(:merge_request) do
+    create(
+      :merge_request,
+      :simple,
+      source_project: project,
+      description: "Description\n\nclosing #{issue_1.to_reference}, #{issue_2.to_reference}"
+    )
+  end
+  let(:textbox) { page.find(:css, '.js-commit-message', visible: false) }
+  let(:include_link) { page.find(:css, '.js-with-description-link', visible: false) }
+  let(:do_not_include_link) { page.find(:css, '.js-without-description-link', visible: false) }
+  let(:default_message) do
+    [
+      "Merge branch 'feature' into 'master'",
+      merge_request.title,
+      "Closes issues #{issue_1.to_reference} and #{issue_2.to_reference}",
+      "See merge request #{merge_request.to_reference}"
+    ].join("\n\n")
+  end
+  let(:message_with_description) do
+    [
+      "Merge branch 'feature' into 'master'",
+      merge_request.title,
+      merge_request.description,
+      "See merge request #{merge_request.to_reference}"
+    ].join("\n\n")
+  end
+
+  before do
+    project.team << [user, :master]
+
+    login_as user
+
+    visit namespace_project_merge_request_path(project.namespace, project, merge_request)
+
+    expect(textbox).not_to be_visible
+    click_link "Modify commit message"
+    expect(textbox).to be_visible
+  end
+
+  it "toggles commit message between message with description and without description " do
+    expect(textbox.value).to eq(default_message)
+
+    click_link "Include description in commit message"
+
+    expect(textbox.value).to eq(message_with_description)
+
+    click_link "Don't include description in commit message"
+
+    expect(textbox.value).to eq(default_message)
+  end
+
+  it "toggles link between 'Include description' and 'Don't include description'" do
+    expect(include_link).to be_visible
+    expect(do_not_include_link).not_to be_visible
+
+    click_link "Include description in commit message"
+
+    expect(include_link).not_to be_visible
+    expect(do_not_include_link).to be_visible
+
+    click_link "Don't include description in commit message"
+
+    expect(include_link).to be_visible
+    expect(do_not_include_link).not_to be_visible
+  end
+end