Add view spec for top

spec/views/shared/milestones/_top.html.haml.rb

+require 'spec_helper'
+
+describe 'shared/milestones/_top.html.haml' do
+  let(:group) { create(:group) }
+  let(:project) { create(:project, group: group) }
+  let(:milestone) { create(:milestone, project: project) }
+
+  before do
+    allow(milestone).to receive(:milestones) { [] }
+  end
+
+  it 'renders a deprecation message for a legacy milestone' do
+    allow(milestone).to receive(:legacy_group_milestone?) { true }
+
+    render 'shared/milestones/top', milestone: milestone
+
+    expect(rendered).to have_css('.milestone-deprecation-message')
+  end
+
+  it 'renders a deprecation message for a dashboard milestone' do
+    allow(milestone).to receive(:dashboard_milestone?) { true }
+
+    render 'shared/milestones/top', milestone: milestone
+
+    expect(rendered).to have_css('.milestone-deprecation-message')
+  end
+
+  it 'does not render a deprecation message for a non-legacy and non-dashboard milestone' do
+    assign :group, group
+
+    render 'shared/milestones/top', milestone: milestone
+
+    expect(rendered).not_to have_css('.milestone-deprecation-message')
+  end
+end