1 files changed, 68 insertions, 0 deletions
diff --git a/spec/lib/gitlab/pagination/keyset/cursor_based_request_context_spec.rb b/spec/lib/gitlab/pagination/keyset/cursor_based_request_context_spec.rb
new file mode 100644
index 00000000000..79de6f230ec
--- /dev/null
+++ b/spec/lib/gitlab/pagination/keyset/cursor_based_request_context_spec.rb
@@ -0,0 +1,68 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe Gitlab::Pagination::Keyset::CursorBasedRequestContext do
+  let(:params) { { per_page: 2, cursor: 'eyJuYW1lIjoiR2l0TGFiIEluc3RhbmNlIiwiaWQiOiI1MiIsIl9rZCI6Im4ifQ==', order_by: :name, sort: :asc } }
+  let(:request) { double('request', url: 'http://localhost') }
+  let(:request_context) { double('request_context', header: nil, params: params, request: request) }
+
+  describe '#per_page' do
+    subject(:per_page) { described_class.new(request_context).per_page }
+
+    it { is_expected.to eq 2 }
+  end
+
+  describe '#cursor' do
+    subject(:cursor) { described_class.new(request_context).cursor }
+
+    it { is_expected.to eq 'eyJuYW1lIjoiR2l0TGFiIEluc3RhbmNlIiwiaWQiOiI1MiIsIl9rZCI6Im4ifQ==' }
+  end
+
+  describe '#order_by' do
+    subject(:order_by) { described_class.new(request_context).order_by }
+
+    it { is_expected.to eq({ name: :asc }) }
+  end
+
+  describe '#apply_headers' do
+    let(:request) { double('request', url: "http://#{Gitlab.config.gitlab.host}/api/v4/projects?per_page=3") }
+    let(:params) { { per_page: 3 } }
+    let(:request_context) { double('request_context', header: nil, params: params, request: request) }
+    let(:cursor_for_next_page) { 'eyJuYW1lIjoiSDVicCIsImlkIjoiMjgiLCJfa2QiOiJuIn0=' }
+
+    subject(:apply_headers) { described_class.new(request_context).apply_headers(cursor_for_next_page) }
+
+    it 'sets Link header with same host/path as the original request' do
+      orig_uri = URI.parse(request_context.request.url)
+
+      expect(request_context).to receive(:header).once do |name, header|
+        first_link, _ = /<([^>]+)>; rel="next"/.match(header).captures
+
+        uri = URI.parse(first_link)
+
+        expect(name).to eq('Link')
+        expect(uri.host).to eq(orig_uri.host)
+        expect(uri.path).to eq(orig_uri.path)
+      end
+
+      apply_headers
+    end
+
+    it 'sets Link header with a cursor to the next page' do
+      orig_uri = URI.parse(request_context.request.url)
+
+      expect(request_context).to receive(:header).once do |name, header|
+        first_link, _ = /<([^>]+)>; rel="next"/.match(header).captures
+
+        query = CGI.parse(URI.parse(first_link).query)
+
+        expect(name).to eq('Link')
+        expect(query.except('cursor')).to eq(CGI.parse(orig_uri.query).except('cursor'))
+        expect(query['cursor']).to eq([cursor_for_next_page])
+      end
+
+      apply_headers
+    end
+  end
+end