1 files changed, 124 insertions, 0 deletions
diff --git a/spec/support/shared_examples/graphql/label_fields.rb b/spec/support/shared_examples/graphql/label_fields.rb
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+++ b/spec/support/shared_examples/graphql/label_fields.rb
@@ -0,0 +1,124 @@
+# frozen_string_literal: true
+
+RSpec.shared_examples 'a GraphQL type with labels' do
+  it 'has label fields' do
+    expected_fields = %w[label labels]
+
+    expect(described_class).to include_graphql_fields(*expected_fields)
+  end
+
+  describe 'label field' do
+    subject { described_class.fields['label'] }
+
+    it { is_expected.to have_graphql_type(Types::LabelType) }
+    it { is_expected.to have_graphql_arguments(:title) }
+  end
+
+  describe 'labels field' do
+    subject { described_class.fields['labels'] }
+
+    it { is_expected.to have_graphql_type(Types::LabelType.connection_type) }
+    it { is_expected.to have_graphql_arguments(:search_term) }
+  end
+end
+
+RSpec.shared_examples 'querying a GraphQL type with labels' do
+  let_it_be(:current_user) { create(:user) }
+
+  let_it_be(:label_a) { create(label_factory, :described, **label_attrs) }
+  let_it_be(:label_b) { create(label_factory, :described, **label_attrs) }
+  let_it_be(:label_c) { create(label_factory, :described, :scoped, prefix: 'matching', **label_attrs) }
+  let_it_be(:label_d) { create(label_factory, :described, :scoped, prefix: 'matching', **label_attrs) }
+
+  let(:label_title) { label_b.title }
+
+  let(:label_params) { { title: label_title } }
+  let(:labels_params) { nil }
+
+  let(:label_response) { graphql_data.dig(*path_prefix, 'label') }
+  let(:labels_response) { graphql_data.dig(*path_prefix, 'labels', 'nodes') }
+
+  let(:query) do
+    make_query(
+      [
+        query_graphql_field(:label, label_params, all_graphql_fields_for(Label)),
+        query_graphql_field(:labels, labels_params, [
+          query_graphql_field(:nodes, nil, all_graphql_fields_for(Label))
+        ])
+      ]
+    )
+  end
+
+  context 'running a query' do
+    before do
+      run_query(query)
+    end
+
+    context 'minimum required arguments' do
+      it 'returns the label information' do
+        expect(label_response).to include(
+          'title' => label_title,
+          'description' => label_b.description
+        )
+      end
+
+      it 'returns the labels information' do
+        expect(labels_response.pluck('title')).to contain_exactly(
+          label_a.title,
+          label_b.title,
+          label_c.title,
+          label_d.title
+        )
+      end
+    end
+
+    context 'with a search param' do
+      let(:labels_params) { { search_term: 'matching' } }
+
+      it 'finds the matching labels' do
+        expect(labels_response.pluck('title')).to contain_exactly(
+          label_c.title,
+          label_d.title
+        )
+      end
+    end
+
+    context 'the label does not exist' do
+      let(:label_title) { 'not-a-label' }
+
+      it 'returns nil' do
+        expect(label_response).to be_nil
+      end
+    end
+  end
+
+  describe 'performance' do
+    def query_for(*labels)
+      selections = labels.map do |label|
+        %Q[#{label.title.gsub(/:+/, '_')}: label(title: "#{label.title}") { description }]
+      end
+
+      make_query(selections)
+    end
+
+    before do
+      run_query(query_for(label_a))
+    end
+
+    it 'batches queries for labels by title' do
+      pending('See: https://gitlab.com/gitlab-org/gitlab/-/issues/217767')
+
+      multi_selection = query_for(label_b, label_c)
+      single_selection = query_for(label_d)
+
+      expect { run_query(multi_selection) }
+        .to issue_same_number_of_queries_as { run_query(single_selection) }
+    end
+  end
+
+  # Run a known good query with the current user
+  def run_query(query)
+    post_graphql(query, current_user: current_user)
+    expect(graphql_errors).not_to be_present
+  end
+end