Deserialize header parameters regardless of casing

lib/committee/schema_validator/open_api_3/parameter_deserializer.rb

@@ -34,6 +34,11 @@ def deserialize_path_params(raw_params)
         # @param [Hash] raw_headers Raw headers
         # @return [Hash] Deserialized headers according to OpenAPI schema
         def deserialize_headers(raw_headers)
+          return raw_headers if raw_headers.nil? || raw_headers.empty?
+
+          raw_headers = raw_headers.transform_keys do |name|
+            @parameters.find { |param| param.in == 'header' && param.name.casecmp?(name.to_s) }&.name || name
+          end
           deserialize_params_by_location(raw_headers, 'header')
         end
 

test/middleware/request_validation_open_api_3_test.rb

@@ -550,6 +550,22 @@ def app
     end
   end
 
+  it 'deserializes header arrays regardless of the case used in the schema' do
+    parameter = { 'name' => 'X-Ids', 'in' => 'header', 'required' => true, 'schema' => { 'type' => 'array', 'items' => { 'type' => 'integer' } }, }
+    check_parameter = lambda { |env|
+      assert_equal [1, 2], env['committee.headers']['X-Ids']
+      refute env['committee.headers'].key?('X-IDS')
+      assert_equal '1,2', env['HTTP_X_IDS']
+      [200, {}, []]
+    }
+    @app = new_rack_app_with_lambda(check_parameter, schema: query_param_schema(parameter))
+
+    header 'X-Ids', '1,2'
+    get '/events'
+
+    assert_equal 200, last_response.status
+  end
+
   describe ':accept_request_filter' do
     [
       { description: 'when not specified, includes everything', accept_request_filter: nil, expected: { status: 400 } },

test/schema_validator/open_api_3/parameter_deserializer_test.rb

@@ -210,6 +210,17 @@
       assert_equal({ 'X-Filter' => { 'role' => 'admin', 'status' => 'active' } }, result)
     end
 
+    it 'matches header names without regard to case' do
+      raw_headers = { 'x-filter' => 'role,admin,status,active', 'X-Other' => 'untouched' }
+      param = create_param('X-Filter', 'header', 'simple', false, 'object', { 'role' => 'string', 'status' => 'string' })
+      deserializer = create_deserializer([param])
+
+      result = deserializer.deserialize_headers(raw_headers)
+
+      assert_equal({ 'X-Filter' => { 'role' => 'admin', 'status' => 'active' }, 'X-Other' => 'untouched' }, result)
+      assert_equal 'role,admin,status,active', raw_headers['x-filter']
+    end
+
     it 'handles empty params gracefully' do
       raw_params = {}
       param = create_param('filter', 'query', 'form', true, 'object', { 'role' => 'string' })