1 files changed, 114 insertions, 0 deletions
diff --git a/spec/lib/gitlab/ci/runner_releases_spec.rb b/spec/lib/gitlab/ci/runner_releases_spec.rb
new file mode 100644
index 00000000000..9e4a8739c0f
--- /dev/null
+++ b/spec/lib/gitlab/ci/runner_releases_spec.rb
@@ -0,0 +1,114 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe Gitlab::Ci::RunnerReleases do
+  subject { described_class.instance }
+
+  describe '#releases' do
+    before do
+      subject.reset!
+
+      stub_application_setting(public_runner_releases_url: 'the release API URL')
+      allow(Gitlab::HTTP).to receive(:try_get).with('the release API URL').once { mock_http_response(response) }
+    end
+
+    def releases
+      subject.releases
+    end
+
+    shared_examples 'requests that follow cache status' do |validity_period|
+      context "almost #{validity_period.inspect} later" do
+        let(:followup_request_interval) { validity_period - 0.001.seconds }
+
+        it 'returns cached releases' do
+          releases
+
+          travel followup_request_interval do
+            expect(Gitlab::HTTP).not_to receive(:try_get)
+
+            expect(releases).to eq(expected_result)
+          end
+        end
+      end
+
+      context "after #{validity_period.inspect}" do
+        let(:followup_request_interval) { validity_period + 1.second }
+        let(:followup_response) { (response || []) + [{ 'name' => 'v14.9.2' }] }
+
+        it 'checks new releases' do
+          releases
+
+          travel followup_request_interval do
+            expect(Gitlab::HTTP).to receive(:try_get).with('the release API URL').once { mock_http_response(followup_response) }
+
+            expect(releases).to eq((expected_result || []) + [Gitlab::VersionInfo.new(14, 9, 2)])
+          end
+        end
+      end
+    end
+
+    context 'when response is nil' do
+      let(:response) { nil }
+      let(:expected_result) { nil }
+
+      it 'returns nil' do
+        expect(releases).to be_nil
+      end
+
+      it_behaves_like 'requests that follow cache status', 5.seconds
+
+      it 'performs exponential backoff on requests', :aggregate_failures do
+        start_time = Time.now.utc.change(usec: 0)
+
+        http_call_timestamp_offsets = []
+        allow(Gitlab::HTTP).to receive(:try_get).with('the release API URL') do
+          http_call_timestamp_offsets << Time.now.utc - start_time
+          mock_http_response(response)
+        end
+
+        # An initial HTTP request fails
+        travel_to(start_time)
+        subject.reset!
+        expect(releases).to be_nil
+
+        # Successive failed requests result in HTTP requests only after specific backoff periods
+        backoff_periods = [5, 10, 20, 40, 80, 160, 320, 640, 1280, 2560, 3600].map(&:seconds)
+        backoff_periods.each do |period|
+          travel(period - 1.second)
+          expect(releases).to be_nil
+
+          travel 1.second
+          expect(releases).to be_nil
+        end
+
+        expect(http_call_timestamp_offsets).to eq([0, 5, 15, 35, 75, 155, 315, 635, 1275, 2555, 5115, 8715])
+
+        # Finally a successful HTTP request results in releases being returned
+        allow(Gitlab::HTTP).to receive(:try_get).with('the release API URL').once { mock_http_response([{ 'name' => 'v14.9.1' }]) }
+        travel 1.hour
+        expect(releases).not_to be_nil
+      end
+    end
+
+    context 'when response is not nil' do
+      let(:response) { [{ 'name' => 'v14.9.1' }, { 'name' => 'v14.9.0' }] }
+      let(:expected_result) { [Gitlab::VersionInfo.new(14, 9, 0), Gitlab::VersionInfo.new(14, 9, 1)] }
+
+      it 'returns parsed and sorted Gitlab::VersionInfo objects' do
+        expect(releases).to eq(expected_result)
+      end
+
+      it_behaves_like 'requests that follow cache status', 1.day
+    end
+
+    def mock_http_response(response)
+      http_response = instance_double(HTTParty::Response)
+
+      allow(http_response).to receive(:success?).and_return(response.present?)
+      allow(http_response).to receive(:parsed_response).and_return(response)
+
+      http_response
+    end
+  end
+end