Change APISecurity::Sampler#sample? to return false on 404

Author: y9v

lib/datadog/appsec/api_security/sampler.rb

@@ -43,6 +43,7 @@ def initialize(sample_delay)
 
         def sample?(request, response)
           return true if @sample_delay_seconds.zero?
+          return false if response.status == 404
 
           key = Zlib.crc32("#{request.request_method}#{RouteExtractor.route_pattern(request)}#{response.status}")
           current_timestamp = Core::Utils::Time.now.to_i

spec/datadog/appsec/api_security/sampler_spec.rb

@@ -74,6 +74,16 @@
       end
     end
 
+    context 'when response status is 404' do
+      let(:response) { double('Rack::Response', status: 404) }
+
+      it 'always returns false' do
+        3.times do
+          expect(sampler.sample?(request, response)).to be(false)
+        end
+      end
+    end
+
     context 'when sampling for the first time' do
       it { expect(sampler.sample?(request, response)).to be(true) }
     end