1 files changed, 147 insertions, 0 deletions
diff --git a/spec/support/shared_examples/controllers/metrics/dashboard/prometheus_api_proxy_shared_examples.rb b/spec/support/shared_examples/controllers/metrics/dashboard/prometheus_api_proxy_shared_examples.rb
new file mode 100644
index 00000000000..94cd6971f7c
--- /dev/null
+++ b/spec/support/shared_examples/controllers/metrics/dashboard/prometheus_api_proxy_shared_examples.rb
@@ -0,0 +1,147 @@
+# frozen_string_literal: true
+
+RSpec.shared_examples_for 'metrics dashboard prometheus api proxy' do
+  let(:service_params) { [proxyable, 'GET', 'query', expected_params] }
+  let(:service_result) { { status: :success, body: prometheus_body } }
+  let(:prometheus_proxy_service) { instance_double(Prometheus::ProxyService) }
+  let(:proxyable_params) do
+    {
+      id: proxyable.id.to_s
+    }
+  end
+  let(:expected_params) do
+    ActionController::Parameters.new(
+      prometheus_proxy_params(
+        proxy_path: 'query',
+        controller: described_class.controller_path,
+        action: 'prometheus_proxy'
+      )
+    ).permit!
+  end
+
+  before do
+    allow_next_instance_of(Prometheus::ProxyService, *service_params) do |proxy_service|
+      allow(proxy_service).to receive(:execute).and_return(service_result)
+    end
+  end
+
+  context 'with valid requests' do
+    context 'with success result' do
+      let(:prometheus_body) { '{"status":"success"}' }
+      let(:prometheus_json_body) { Gitlab::Json.parse(prometheus_body) }
+
+      it 'returns prometheus response' do
+        get :prometheus_proxy, params: prometheus_proxy_params
+
+        expect(Prometheus::ProxyService).to have_received(:new).with(*service_params)
+        expect(response).to have_gitlab_http_status(:ok)
+        expect(json_response).to eq(prometheus_json_body)
+      end
+
+      context 'with nil query' do
+        let(:params_without_query) do
+          prometheus_proxy_params.except(:query)
+        end
+
+        before do
+          expected_params.delete(:query)
+        end
+
+        it 'does not raise error' do
+          get :prometheus_proxy, params: params_without_query
+
+          expect(Prometheus::ProxyService).to have_received(:new).with(*service_params)
+        end
+      end
+    end
+
+    context 'with nil result' do
+      let(:service_result) { nil }
+
+      it 'returns 204 no_content' do
+        get :prometheus_proxy, params: prometheus_proxy_params
+
+        expect(json_response['status']).to eq(_('processing'))
+        expect(json_response['message']).to eq(_('Not ready yet. Try again later.'))
+        expect(response).to have_gitlab_http_status(:no_content)
+      end
+    end
+
+    context 'with 404 result' do
+      let(:service_result) { { http_status: 404, status: :success, body: '{"body": "value"}' } }
+
+      it 'returns body' do
+        get :prometheus_proxy, params: prometheus_proxy_params
+
+        expect(response).to have_gitlab_http_status(:not_found)
+        expect(json_response['body']).to eq('value')
+      end
+    end
+
+    context 'with error result' do
+      context 'with http_status' do
+        let(:service_result) do
+          { http_status: :service_unavailable, status: :error, message: 'error message' }
+        end
+
+        it 'sets the http response status code' do
+          get :prometheus_proxy, params: prometheus_proxy_params
+
+          expect(response).to have_gitlab_http_status(:service_unavailable)
+          expect(json_response['status']).to eq('error')
+          expect(json_response['message']).to eq('error message')
+        end
+      end
+
+      context 'without http_status' do
+        let(:service_result) { { status: :error, message: 'error message' } }
+
+        it 'returns bad_request' do
+          get :prometheus_proxy, params: prometheus_proxy_params
+
+          expect(response).to have_gitlab_http_status(:bad_request)
+          expect(json_response['status']).to eq('error')
+          expect(json_response['message']).to eq('error message')
+        end
+      end
+    end
+  end
+
+  context 'with inappropriate requests' do
+    let(:prometheus_body) { nil }
+
+    context 'without correct permissions' do
+      let(:user2) { create(:user) }
+
+      before do
+        sign_out(user)
+        sign_in(user2)
+      end
+
+      it 'returns 404' do
+        get :prometheus_proxy, params: prometheus_proxy_params
+
+        expect(response).to have_gitlab_http_status(:not_found)
+      end
+    end
+  end
+
+  context 'with invalid proxyable id' do
+    let(:prometheus_body) { nil }
+
+    it 'returns 404' do
+      get :prometheus_proxy, params: prometheus_proxy_params(id: proxyable.id + 1)
+
+      expect(response).to have_gitlab_http_status(:not_found)
+    end
+  end
+
+  private
+
+  def prometheus_proxy_params(params = {})
+    {
+      proxy_path: 'query',
+      query: '1'
+    }.merge(proxyable_params).merge(params)
+  end
+end