Track and act upon the number of executed queriesquery-counts

This ensures that we have more visibility in the number of SQL queries
that are executed in web requests. The current threshold is hardcoded to
100 as we will rarely (maybe once or twice) change it.

In production and development we use Sentry if enabled, in the test
environment we raise an error. This feature is also only enabled in
production/staging when running on GitLab.com as it's not very useful to
other users.

1 files changed, 72 insertions, 0 deletions

diff --git a/spec/lib/gitlab/query_limiting/middleware_spec.rb b/spec/lib/gitlab/query_limiting/middleware_spec.rb
new file mode 100644
index 00000000000..a04bcdecb4b
--- /dev/null
+++ b/spec/lib/gitlab/query_limiting/middleware_spec.rb
@@ -0,0 +1,72 @@
+require 'spec_helper'
+
+describe Gitlab::QueryLimiting::Middleware do
+  describe '#call' do
+    it 'runs the application with query limiting in place' do
+      middleware = described_class.new(-> (env) { env })
+
+      expect_any_instance_of(Gitlab::QueryLimiting::Transaction)
+        .to receive(:act_upon_results)
+
+      expect(middleware.call({ number: 10 }))
+        .to eq({ number: 10 })
+    end
+  end
+
+  describe '#action_name' do
+    let(:middleware) { described_class.new(-> (env) { env }) }
+
+    context 'using a Rails request' do
+      it 'returns the name of the controller and action' do
+        env = {
+          described_class::CONTROLLER_KEY => double(
+            :controller,
+            action_name: 'show',
+            class: double(:class, name: 'UsersController'),
+            content_type: 'text/html'
+          )
+        }
+
+        expect(middleware.action_name(env)).to eq('UsersController#show')
+      end
+
+      it 'includes the content type if this is not text/html' do
+        env = {
+          described_class::CONTROLLER_KEY => double(
+            :controller,
+            action_name: 'show',
+            class: double(:class, name: 'UsersController'),
+            content_type: 'application/json'
+          )
+        }
+
+        expect(middleware.action_name(env))
+          .to eq('UsersController#show (application/json)')
+      end
+    end
+
+    context 'using a Grape API request' do
+      it 'returns the name of the request method and endpoint path' do
+        env = {
+          described_class::ENDPOINT_KEY => double(
+            :endpoint,
+            route: double(:route, request_method: 'GET', path: '/foo')
+          )
+        }
+
+        expect(middleware.action_name(env)).to eq('GET /foo')
+      end
+
+      it 'returns nil if the route can not be retrieved' do
+        endpoint = double(:endpoint)
+        env = { described_class::ENDPOINT_KEY => endpoint }
+
+        allow(endpoint)
+          .to receive(:route)
+          .and_raise(RuntimeError)
+
+        expect(middleware.action_name(env)).to be_nil
+      end
+    end
+  end
+end