Merge branch '65988-optimize-snippet-listings' into 'master'

Optimize queries for snippet listings

See merge request gitlab-org/gitlab-ce!32576

spec/controllers/snippets_controller_spec.rb

@@ -9,6 +9,15 @@ describe SnippetsController do
     let(:user) { create(:user) }
     context 'when username parameter is present' do
+      it_behaves_like 'paginated collection' do
+        let(:collection) { Snippet.all }
+        let(:params) { { username: user.username } }
+
+        before do
+          create(:personal_snippet, :public, author: user)
+        end
+      end
+
       it 'renders snippets of a user when username is present' do
         get :index, params: { username: user.username }

spec/lib/gitlab/noteable_metadata_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe Gitlab::NoteableMetadata do
+  subject { Class.new { include Gitlab::NoteableMetadata }.new }
+
+  it 'returns an empty Hash if an empty collection is provided' do
+    expect(subject.noteable_meta_data(Snippet.none, 'Snippet')).to eq({})
+  end
+
+  it 'raises an error when given a collection with no limit' do
+    expect { subject.noteable_meta_data(Snippet.all, 'Snippet') }.to raise_error(/must have a limit/)
+  end
+
+  context 'snippets' do
+    let!(:snippet) { create(:personal_snippet) }
+    let!(:other_snippet) { create(:personal_snippet) }
+    let!(:note) { create(:note, noteable: snippet) }
+
+    it 'aggregates stats on snippets' do
+      data = subject.noteable_meta_data(Snippet.all.limit(10), 'Snippet')
+
+      expect(data.count).to eq(2)
+      expect(data[snippet.id].user_notes_count).to eq(1)
+      expect(data[other_snippet.id].user_notes_count).to eq(0)
+    end
+  end
+end

spec/support/shared_examples/controllers/paginated_collection_shared_examples.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+shared_examples 'paginated collection' do
+  let(:collection) { nil }
+  let(:last_page) { collection.page.total_pages }
+  let(:action) { :index }
+  let(:params) { {} }
+
+  it 'renders a page number that is not ouf of range' do
+    get action, params: params.merge(page: last_page)
+
+    expect(response).to have_gitlab_http_status(200)
+  end
+
+  it 'redirects to last_page if page number is larger than number of pages' do
+    get action, params: params.merge(page: last_page + 1)
+
+    expect(response).to redirect_to(params.merge(page: last_page))
+  end
+
+  it 'does not redirect to external sites when provided a host field' do
+    external_host = 'www.example.com'
+
+    get action, params: params.merge(page: last_page + 1, host: external_host)
+
+    expect(response).to redirect_to(params.merge(page: last_page))
+  end
+end