Copied original whitespace button test, ready to add to compare diffs

spec/features/projects/compare/toggle_whitespace_changes.rb

+require 'spec_helper'
+
+feature 'Toggle Whitespace Changes', js: true, feature: true do
+  before do
+    login_as :admin
+    # something = create(:something)
+    # project = something.something_project
+    # visit diffs_namespace_project_something_path(project.namespace, project, something)
+  end
+
+  it 'has a button to toggle whitespace changes' do
+    expect(page).to have_content 'Hide whitespace changes'
+  end
+
+  describe 'clicking "Hide whitespace changes" button' do
+    it 'toggles the "Hide whitespace changes" button' do
+      click_link 'Hide whitespace changes'
+
+      expect(page).to have_content 'Show whitespace changes'
+    end
+  end
+end