Fix nullable QueryMap fails to compile

chopper/test/base_test.dart

@@ -591,6 +591,160 @@ void main() {
     });
   });
 
+  test('Query Map 3', () async {
+    final httpClient = MockClient((request) async {
+      expect(
+        request.url.toString(),
+        equals('$baseUrl/test/query_map?name=foo&number=1234'),
+      );
+      expect(request.method, equals('GET'));
+
+      return http.Response('get response', 200);
+    });
+
+    final chopper = buildClient(httpClient);
+    final service = chopper.getService<HttpTestService>();
+
+    final response = await service.getQueryMapTest3(
+      name: 'foo',
+      number: 1234,
+    );
+
+    expect(response.body, equals('get response'));
+    expect(response.statusCode, equals(200));
+
+    httpClient.close();
+  });
+
+  test('Query Map 4 without QueryMap', () async {
+    final httpClient = MockClient((request) async {
+      expect(
+        request.url.toString(),
+        equals('$baseUrl/test/query_map?name=foo&number=1234'),
+      );
+      expect(request.method, equals('GET'));
+
+      return http.Response('get response', 200);
+    });
+
+    final chopper = buildClient(httpClient);
+    final service = chopper.getService<HttpTestService>();
+
+    final response = await service.getQueryMapTest4(
+      name: 'foo',
+      number: 1234,
+    );
+
+    expect(response.body, equals('get response'));
+    expect(response.statusCode, equals(200));
+
+    httpClient.close();
+  });
+
+  test('Query Map 4 with QueryMap', () async {
+    final httpClient = MockClient((request) async {
+      expect(
+        request.url.toString(),
+        equals('$baseUrl/test/query_map?name=foo&number=1234&filter_1=filter_value_1'),
+      );
+      expect(request.method, equals('GET'));
+
+      return http.Response('get response', 200);
+    });
+
+    final chopper = buildClient(httpClient);
+    final service = chopper.getService<HttpTestService>();
+
+    final response = await service.getQueryMapTest4(
+      name: 'foo',
+      number: 1234,
+      filters: {
+        'filter_1': 'filter_value_1'
+      }
+    );
+
+    expect(response.body, equals('get response'));
+    expect(response.statusCode, equals(200));
+
+    httpClient.close();
+  });
+
+  test('Query Map 4 with QueryMap that overwrites a previous value from Query', () async {
+    final httpClient = MockClient((request) async {
+      expect(
+        request.url.toString(),
+        equals('$baseUrl/test/query_map?name=bar&number=1234'),
+      );
+      expect(request.method, equals('GET'));
+
+      return http.Response('get response', 200);
+    });
+
+    final chopper = buildClient(httpClient);
+    final service = chopper.getService<HttpTestService>();
+
+    final response = await service.getQueryMapTest4(
+        name: 'foo',
+        number: 1234,
+        filters: {
+          'name': 'bar'
+        }
+    );
+
+    expect(response.body, equals('get response'));
+    expect(response.statusCode, equals(200));
+
+    httpClient.close();
+  });
+
+  test('Query Map 5 without QueryMap', () async {
+    final httpClient = MockClient((request) async {
+      expect(
+        request.url.toString(),
+        equals('$baseUrl/test/query_map'),
+      );
+      expect(request.method, equals('GET'));
+
+      return http.Response('get response', 200);
+    });
+
+    final chopper = buildClient(httpClient);
+    final service = chopper.getService<HttpTestService>();
+
+    final response = await service.getQueryMapTest5();
+
+    expect(response.body, equals('get response'));
+    expect(response.statusCode, equals(200));
+
+    httpClient.close();
+  });
+
+  test('Query Map 5 with QueryMap', () async {
+    final httpClient = MockClient((request) async {
+      expect(
+        request.url.toString(),
+        equals('$baseUrl/test/query_map?filter_1=filter_value_1'),
+      );
+      expect(request.method, equals('GET'));
+
+      return http.Response('get response', 200);
+    });
+
+    final chopper = buildClient(httpClient);
+    final service = chopper.getService<HttpTestService>();
+
+    final response = await service.getQueryMapTest5(
+      filters: {
+        'filter_1': 'filter_value_1'
+      }
+    );
+
+    expect(response.body, equals('get response'));
+    expect(response.statusCode, equals(200));
+
+    httpClient.close();
+  });
+
   test('onRequest Stream', () async {
     final client = MockClient((http.Request req) async {
       return http.Response('ok', 200);

chopper/test/test_service.dart

@@ -48,6 +48,25 @@ abstract class HttpTestService extends ChopperService {
     @Query('test') bool? test,
   });
 
+  @Get(path: 'query_map')
+  Future<Response> getQueryMapTest3({
+    @Query('name') String name = '',
+    @Query('number') int? number,
+    @QueryMap() Map<String, dynamic> filters = const {},
+  });
+
+  @Get(path: 'query_map')
+  Future<Response> getQueryMapTest4({
+    @Query('name') String name = '',
+    @Query('number') int? number,
+    @QueryMap() Map<String, dynamic>? filters,
+  });
+
+  @Get(path: 'query_map')
+  Future<Response> getQueryMapTest5({
+    @QueryMap() Map<String, dynamic>? filters,
+  });
+
   @Get(path: 'get_body')
   Future<Response> getBody(@Body() dynamic body);
 

chopper_generator/lib/src/generator.dart

@@ -10,6 +10,7 @@ import 'package:built_collection/built_collection.dart';
 import 'package:dart_style/dart_style.dart';
 
 import 'package:source_gen/source_gen.dart';
+
 // TODO(lejard_h) Code builder not null safe yet
 // ignore: import_of_legacy_library_into_null_safe
 import 'package:code_builder/code_builder.dart';
@@ -82,7 +83,7 @@ class ChopperGenerator extends GeneratorForAnnotation<chopper.ChopperApi> {
     });
 
     final ignore =
-        '// ignore_for_file: always_put_control_body_on_new_line, always_specify_types, prefer_const_declarations, unnecessary_brace_in_string_interps';
+        '// ignore_for_file: always_put_control_body_on_new_line, always_specify_types, dead_null_aware_expression, prefer_const_declarations, unnecessary_brace_in_string_interps';
     final emitter = DartEmitter();
     return DartFormatter().format('$ignore\n${classBuilder.accept(emitter)}');
   }
@@ -175,11 +176,14 @@ class ChopperGenerator extends GeneratorForAnnotation<chopper.ChopperApi> {
       if (hasQueryMap) {
         if (queries.isNotEmpty) {
           blocks.add(refer('$_parametersVar.addAll').call(
-            [refer(queryMap.keys.first)],
+            [refer(queryMap.keys.first).ifNullThen(refer('{}'))],
           ).statement);
         } else {
           blocks.add(
-            refer(queryMap.keys.first).assignFinal(_parametersVar).statement,
+            refer(queryMap.keys.first)
+                .ifNullThen(refer('{}'))
+                .assignFinal(_parametersVar)
+                .statement,
           );
         }
       }