Deserialize bracket-suffixed array query parameters

lib/committee/schema_validator/open_api_3/parameter_deserializer.rb

@@ -116,6 +116,19 @@ def convert_to_indifferent_hash(hash)
         # @return [Hash]
         def normalize_raw_params(raw_params, location, params_for_location)
           return raw_params unless location == 'query'
+
+          normalized = raw_params
+          params_for_location.each do |param_def|
+            next unless param_def.name.end_with?('[]') && param_def.schema&.type == 'array'
+
+            raw_name = param_def.name.delete_suffix('[]')
+            next unless normalized[raw_name].is_a?(Array)
+
+            normalized = raw_params.dup if normalized.equal?(raw_params)
+            normalized[param_def.name] = normalized.delete(raw_name)
+          end
+
+          raw_params = normalized
           return raw_params unless raw_params.values.any? { |value| value.is_a?(Hash) }
           return raw_params unless requires_query_param_flattening?(params_for_location)
 

test/middleware/request_validation_open_api_3_test.rb

@@ -661,6 +661,20 @@ def app
   end
 
   describe 'bracket-style query params' do
+    it 'deserializes array params whose name ends with brackets' do
+      parameter = { 'name' => 'ids[]', 'in' => 'query', 'required' => true, 'schema' => { 'type' => 'array', 'items' => { 'type' => 'integer' } }, }
+      check_parameter = lambda { |env|
+        assert_equal [1, 2], env['committee.query_hash']['ids[]']
+        assert_equal ['1', '2'], env['rack.request.query_hash']['ids']
+        [200, {}, []]
+      }
+      @app = new_rack_app_with_lambda(check_parameter, schema: query_param_schema(parameter))
+
+      get '/events?ids[]=1&ids[]=2'
+
+      assert_equal 200, last_response.status
+    end
+
     it 'validates query params declared with bracket notation names' do
       check_parameter = lambda { |env|
         assert_equal '/test', env['committee.query_hash']['filter[slug]']