skip passing waf addresses when the value is empty

lib/datadog/appsec/processor.rb

@@ -22,6 +22,15 @@ def run(input, timeout = WAF::LibDDWAF::DDWAF_RUN_TIMEOUT)
 
           start_ns = Core::Utils::Time.get_time(:nanosecond)
 
+          input.reject! do |_, v|
+            case v
+            when TrueClass, FalseClass
+              false
+            else
+              v.nil? ? true : v.empty?
+            end
+          end
+
           _code, res = @context.run(input, timeout)
 
           stop_ns = Core::Utils::Time.get_time(:nanosecond)

sig/datadog/appsec/processor.rbs

@@ -15,7 +15,7 @@ module Datadog
         @run_mutex: ::Thread::Mutex
 
         def initialize: (Processor processor) -> void
-        def run: (data input, ?::Integer timeout) -> WAF::Result
+        def run: (Hash[untyped, untyped] input, ?::Integer timeout) -> WAF::Result
         def extract_schema: () -> WAF::Result?
         def finalize: () -> void
 

spec/datadog/appsec/processor_spec.rb

@@ -217,6 +217,80 @@
       matches.map(&:actions)
     end
 
+    context 'clear key with empty values' do
+      it 'removes nil values' do
+        input = {
+          'nil_value' => nil,
+          'string_value' => 'hello'
+        }
+        expect(context.instance_variable_get(:@context)).to receive(:run).with(
+          {
+            'string_value' => 'hello'
+          },
+          timeout
+        ).and_call_original
+
+        context.run(input, timeout)
+      end
+
+      it 'do not removes boolean values' do
+        input = {
+          'false_value' => false,
+          'true_value' => true
+        }
+        expect(context.instance_variable_get(:@context)).to receive(:run).with(
+          input, timeout
+        ).and_call_original
+
+        context.run(input, timeout)
+      end
+
+      it 'removes empty string values' do
+        input = {
+          'empty_string_value' => '',
+          'string_value' => 'hello'
+        }
+        expect(context.instance_variable_get(:@context)).to receive(:run).with(
+          {
+            'string_value' => 'hello'
+          },
+          timeout
+        ).and_call_original
+
+        context.run(input, timeout)
+      end
+
+      it 'removes empty arrays values' do
+        input = {
+          'empty_array' => [],
+          'non_empty_array_value' => [1, 2],
+        }
+        expect(context.instance_variable_get(:@context)).to receive(:run).with(
+          {
+            'non_empty_array_value' => [1, 2]
+          },
+          timeout
+        ).and_call_original
+
+        context.run(input, timeout)
+      end
+
+      it 'removes empty hash values' do
+        input = {
+          'empty_hash' => {},
+          'non_empty_hash_value' => { 'hello' => 'world' },
+        }
+        expect(context.instance_variable_get(:@context)).to receive(:run).with(
+          {
+            'non_empty_hash_value' => { 'hello' => 'world' }
+          },
+          timeout
+        ).and_call_original
+
+        context.run(input, timeout)
+      end
+    end
+
     context 'no attack' do
       let(:input) { input_safe }