1 files changed, 107 insertions, 0 deletions
diff --git a/spec/lib/grafana/client_spec.rb b/spec/lib/grafana/client_spec.rb
new file mode 100644
index 00000000000..bd93a3c59a2
--- /dev/null
+++ b/spec/lib/grafana/client_spec.rb
@@ -0,0 +1,107 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe Grafana::Client do
+  let(:grafana_url) { 'https://grafanatest.com/-/grafana-project' }
+  let(:token) { 'test-token' }
+
+  subject(:client) { described_class.new(api_url: grafana_url, token: token) }
+
+  shared_examples 'calls grafana api' do
+    let!(:grafana_api_request) { stub_grafana_request(grafana_api_url) }
+
+    it 'calls grafana api' do
+      subject
+
+      expect(grafana_api_request).to have_been_requested
+    end
+  end
+
+  shared_examples 'no redirects' do
+    let(:redirect_to) { 'https://redirected.example.com' }
+    let(:other_url) { 'https://grafana.example.org' }
+
+    let!(:redirected_req_stub) { stub_grafana_request(other_url) }
+
+    let!(:redirect_req_stub) do
+      stub_grafana_request(
+        grafana_api_url,
+        status: 302,
+        headers: { location: redirect_to }
+      )
+    end
+
+    it 'does not follow redirects' do
+      expect { subject }.to raise_exception(
+        Grafana::Client::Error,
+        'Grafana response status code: 302'
+      )
+
+      expect(redirect_req_stub).to have_been_requested
+      expect(redirected_req_stub).not_to have_been_requested
+    end
+  end
+
+  shared_examples 'handles exceptions' do
+    exceptions = {
+      Gitlab::HTTP::Error => 'Error when connecting to Grafana',
+      Net::OpenTimeout => 'Connection to Grafana timed out',
+      SocketError => 'Received SocketError when trying to connect to Grafana',
+      OpenSSL::SSL::SSLError => 'Grafana returned invalid SSL data',
+      Errno::ECONNREFUSED => 'Connection refused',
+      StandardError => 'Grafana request failed due to StandardError'
+    }
+
+    exceptions.each do |exception, message|
+      context "#{exception}" do
+        before do
+          stub_request(:get, grafana_api_url).to_raise(exception)
+        end
+
+        it do
+          expect { subject }
+            .to raise_exception(Grafana::Client::Error, message)
+        end
+      end
+    end
+  end
+
+  describe '#proxy_datasource' do
+    let(:grafana_api_url) do
+      'https://grafanatest.com/-/grafana-project/' \
+        'api/datasources/proxy/' \
+        '1/api/v1/query_range' \
+        '?query=rate(relevant_metric)' \
+        '&start=1570441248&end=1570444848&step=900'
+    end
+
+    subject do
+      client.proxy_datasource(
+        datasource_id: '1',
+        proxy_path: 'api/v1/query_range',
+        query: {
+          query: 'rate(relevant_metric)',
+          start: 1570441248,
+          end: 1570444848,
+          step: 900
+        }
+      )
+    end
+
+    it_behaves_like 'calls grafana api'
+    it_behaves_like 'no redirects'
+    it_behaves_like 'handles exceptions'
+  end
+
+  private
+
+  def stub_grafana_request(url, body: {}, status: 200, headers: {})
+    stub_request(:get, url)
+      .to_return(
+        status: status,
+        headers: { 'Content-Type' => 'application/json' }.merge(headers),
+        body: body.to_json
+      )
+  end
+end