1 files changed, 104 insertions, 0 deletions
diff --git a/spec/models/project_services/prometheus_service_spec.rb b/spec/models/project_services/prometheus_service_spec.rb
new file mode 100644
index 00000000000..d15079b686b
--- /dev/null
+++ b/spec/models/project_services/prometheus_service_spec.rb
@@ -0,0 +1,104 @@
+require 'spec_helper'
+
+describe PrometheusService, models: true, caching: true do
+  include PrometheusHelpers
+  include ReactiveCachingHelpers
+
+  let(:project) { create(:prometheus_project) }
+  let(:service) { project.prometheus_service }
+
+  describe "Associations" do
+    it { is_expected.to belong_to :project }
+  end
+
+  describe 'Validations' do
+    context 'when service is active' do
+      before { subject.active = true }
+
+      it { is_expected.to validate_presence_of(:api_url) }
+    end
+
+    context 'when service is inactive' do
+      before { subject.active = false }
+
+      it { is_expected.not_to validate_presence_of(:api_url) }
+    end
+  end
+
+  describe '#test' do
+    let!(:req_stub) { stub_prometheus_request(prometheus_query_url('1'), body: prometheus_value_body('vector')) }
+
+    context 'success' do
+      it 'reads the discovery endpoint' do
+        expect(service.test[:success]).to be_truthy
+        expect(req_stub).to have_been_requested
+      end
+    end
+
+    context 'failure' do
+      let!(:req_stub) { stub_prometheus_request(prometheus_query_url('1'), status: 404) }
+
+      it 'fails to read the discovery endpoint' do
+        expect(service.test[:success]).to be_falsy
+        expect(req_stub).to have_been_requested
+      end
+    end
+  end
+
+  describe '#metrics' do
+    let(:environment) { build_stubbed(:environment, slug: 'env-slug') }
+    subject { service.metrics(environment) }
+
+    around do |example|
+      Timecop.freeze { example.run }
+    end
+
+    context 'with valid data' do
+      before do
+        stub_reactive_cache(service, prometheus_data, 'env-slug')
+      end
+
+      it 'returns reactive data' do
+        is_expected.to eq(prometheus_data)
+      end
+    end
+  end
+
+  describe '#calculate_reactive_cache' do
+    let(:environment) { build_stubbed(:environment, slug: 'env-slug') }
+
+    around do |example|
+      Timecop.freeze { example.run }
+    end
+
+    subject do
+      service.calculate_reactive_cache(environment.slug)
+    end
+
+    context 'when service is inactive' do
+      before do
+        service.active = false
+      end
+
+      it { is_expected.to be_nil }
+    end
+
+    context 'when Prometheus responds with valid data' do
+      before do
+        stub_all_prometheus_requests(environment.slug)
+      end
+
+      it { expect(subject.to_json).to eq(prometheus_data.to_json) }
+    end
+
+    [404, 500].each do |status|
+      context "when Prometheus responds with #{status}" do
+        before do
+          stub_all_prometheus_requests(environment.slug, status: status, body: 'QUERY FAILED!')
+        end
+
+        it { is_expected.to eq(success: false, result: %(#{status} - "QUERY FAILED!")) }
+      end
+    end
+  end
+end