1 files changed, 79 insertions, 0 deletions
diff --git a/spec/lib/gitlab/sherlock/middleware_spec.rb b/spec/lib/gitlab/sherlock/middleware_spec.rb
new file mode 100644
index 00000000000..aa74fc53a79
--- /dev/null
+++ b/spec/lib/gitlab/sherlock/middleware_spec.rb
@@ -0,0 +1,79 @@
+require 'spec_helper'
+
+describe Gitlab::Sherlock::Middleware do
+  let(:app) { double(:app) }
+  let(:middleware) { described_class.new(app) }
+
+  describe '#call' do
+    describe 'when instrumentation is enabled' do
+      it 'instruments a request' do
+        allow(middleware).to receive(:instrument?).and_return(true)
+        allow(middleware).to receive(:call_with_instrumentation)
+
+        middleware.call({})
+      end
+    end
+
+    describe 'when instrumentation is disabled' do
+      it "doesn't instrument a request" do
+        allow(middleware).to receive(:instrument).and_return(false)
+        allow(app).to receive(:call)
+
+        middleware.call({})
+      end
+    end
+  end
+
+  describe '#call_with_instrumentation' do
+    it 'instruments a request' do
+      trans = double(:transaction)
+      retval = 'cats are amazing'
+      env = {}
+
+      allow(app).to receive(:call).with(env).and_return(retval)
+      allow(middleware).to receive(:transaction_from_env).and_return(trans)
+      allow(trans).to receive(:run).and_yield.and_return(retval)
+      allow(Gitlab::Sherlock.collection).to receive(:add).with(trans)
+
+      middleware.call_with_instrumentation(env)
+    end
+  end
+
+  describe '#instrument?' do
+    it 'returns false for a text/css request' do
+      env = { 'HTTP_ACCEPT' => 'text/css', 'REQUEST_URI' => '/' }
+
+      expect(middleware.instrument?(env)).to eq(false)
+    end
+
+    it 'returns false for a request to a Sherlock route' do
+      env = {
+        'HTTP_ACCEPT' => 'text/html',
+        'REQUEST_URI' => '/sherlock/transactions'
+      }
+
+      expect(middleware.instrument?(env)).to eq(false)
+    end
+
+    it 'returns true for a request that should be instrumented' do
+      env = {
+        'HTTP_ACCEPT' => 'text/html',
+        'REQUEST_URI' => '/cats'
+      }
+
+      expect(middleware.instrument?(env)).to eq(true)
+    end
+  end
+
+  describe '#transaction_from_env' do
+    it 'returns a Transaction' do
+      env = {
+        'HTTP_ACCEPT' => 'text/html',
+        'REQUEST_URI' => '/cats'
+      }
+
+      expect(middleware.transaction_from_env(env)).
+        to be_an_instance_of(Gitlab::Sherlock::Transaction)
+    end
+  end
+end