Add security response id to AppSec redirect response

lib/datadog/appsec/response.rb

@@ -50,10 +50,15 @@ def block_response(interrupt_params, http_accept_header)
 
         def redirect_response(interrupt_params)
           status_code = interrupt_params['status_code'].to_i
+          location = interrupt_params.fetch('location')
+
+          if (security_response_id = interrupt_params.fetch('security_response_id'))
+            location.gsub!(SECURITY_RESPONSE_ID_PLACEHOLDER, security_response_id)
+          end
 
           Response.new(
             status: ((status_code >= 300 && status_code < 400) ? status_code : 303),
-            headers: {'Location' => interrupt_params.fetch('location')},
+            headers: {'Location' => location},
             body: [],
           )
         end

spec/datadog/appsec/response_spec.rb

@@ -89,12 +89,14 @@
         let(:interrupt_params) do
           {
             'location' => location,
-            'status_code' => status_code
+            'status_code' => status_code,
+            'security_response_id' => security_response_id
           }
         end
 
-        let(:location) { 'foo' }
+        let(:location) { 'example.com' }
         let(:status_code) { '303' }
+        let(:security_response_id) { '73bb7b99-52f6-43ea-998c-6cbc6b80f520' }
 
         context 'status_code' do
           subject(:status) { described_class.from_interrupt_params(interrupt_params, http_accept_header).status }
@@ -117,9 +119,23 @@
         context 'headers' do
           subject(:headers) { described_class.from_interrupt_params(interrupt_params, http_accept_header).headers }
 
-          context 'Location' do
-            it 'uses the one from the configuration' do
-              expect(headers['Location']).to eq('foo')
+          it 'sets Location header' do
+            expect(headers['Location']).to eq("example.com")
+          end
+
+          context 'when location contains security response id placeholder' do
+            let(:location) { 'example.com?security_response_id=[security_response_id]' }
+
+            it 'sets Location header with substituted security response id placeholder' do
+              expect(headers['Location']).to eq("example.com?security_response_id=#{security_response_id}")
+            end
+
+            context 'when security_response_id is missing in action params' do
+              let(:security_response_id) { nil }
+
+              it 'sets Location header without removing security response id placeholder' do
+                expect(headers['Location']).to eq('example.com?security_response_id=[security_response_id]')
+              end
             end
           end
         end