Add latest changes from gitlab-org/gitlab@master

1 files changed, 97 insertions, 0 deletions

diff --git a/spec/lib/api/helpers/pagination_strategies_spec.rb b/spec/lib/api/helpers/pagination_strategies_spec.rb
new file mode 100644
index 00000000000..a418c09a824
--- /dev/null
+++ b/spec/lib/api/helpers/pagination_strategies_spec.rb
@@ -0,0 +1,97 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe API::Helpers::PaginationStrategies do
+  subject { Class.new.include(described_class).new }
+
+  let(:expected_result) { double("result") }
+  let(:relation) { double("relation") }
+  let(:params) { {} }
+
+  before do
+    allow(subject).to receive(:params).and_return(params)
+  end
+
+  describe '#paginate_with_strategies' do
+    let(:paginator) { double("paginator", paginate: expected_result, finalize: nil) }
+
+    before do
+      allow(subject).to receive(:paginator).with(relation).and_return(paginator)
+    end
+
+    it 'yields paginated relation' do
+      expect { |b| subject.paginate_with_strategies(relation, &b) }.to yield_with_args(expected_result)
+    end
+
+    it 'calls #finalize with first value returned from block' do
+      return_value = double
+      expect(paginator).to receive(:finalize).with(return_value)
+
+      subject.paginate_with_strategies(relation) do |records|
+        some_options = {}
+        [return_value, some_options]
+      end
+    end
+
+    it 'returns whatever the block returns' do
+      return_value = [double, double]
+
+      result = subject.paginate_with_strategies(relation) do |records|
+        return_value
+      end
+
+      expect(result).to eq(return_value)
+    end
+  end
+
+  describe '#paginator' do
+    context 'offset pagination' do
+      let(:paginator) { double("paginator") }
+
+      before do
+        allow(subject).to receive(:keyset_pagination_enabled?).and_return(false)
+      end
+
+      it 'delegates to OffsetPagination' do
+        expect(Gitlab::Pagination::OffsetPagination).to receive(:new).with(subject).and_return(paginator)
+
+        expect(subject.paginator(relation)).to eq(paginator)
+      end
+    end
+
+    context 'for keyset pagination' do
+      let(:params) { { pagination: 'keyset' } }
+      let(:request_context) { double('request context') }
+      let(:pager) { double('pager') }
+
+      before do
+        allow(subject).to receive(:keyset_pagination_enabled?).and_return(true)
+        allow(Gitlab::Pagination::Keyset::RequestContext).to receive(:new).with(subject).and_return(request_context)
+      end
+
+      context 'when keyset pagination is available' do
+        before do
+          allow(Gitlab::Pagination::Keyset).to receive(:available?).and_return(true)
+          allow(Gitlab::Pagination::Keyset::Pager).to receive(:new).with(request_context).and_return(pager)
+        end
+
+        it 'delegates to Pager' do
+          expect(subject.paginator(relation)).to eq(pager)
+        end
+      end
+
+      context 'when keyset pagination is not available' do
+        before do
+          allow(Gitlab::Pagination::Keyset).to receive(:available?).with(request_context, relation).and_return(false)
+        end
+
+        it 'renders a 501 error' do
+          expect(subject).to receive(:error!).with(/not yet available/, 405)
+
+          subject.paginator(relation)
+        end
+      end
+    end
+  end
+end