Null check operator used on a null value

[goflutterjava]

original class

class OpenApiAsyncDebug {
  final name = "open async debug";

  Future<String> helloWorld() async {
    return "helloWorld";
  }

  Future<String> echo(String str) async {
    return str;
  }
}

bridge class

import 'package:dart_eval/dart_eval_bridge.dart';

class OpenApiAsyncBridge {
  static const $type = BridgeTypeReference.unresolved(
      BridgeUnresolvedTypeReference(
          'package:paas_dashboard_flutter/open/open_api_debug_async.dart', 'OpenApiAsyncDebug'),
      []);

  static const $declaration = BridgeClassDeclaration($type, isAbstract: false, constructors: {}, methods: {
    'helloWorld': BridgeMethodDeclaration(
        false,
        BridgeFunctionDescriptor(
            BridgeTypeAnnotation(
                BridgeTypeReference.unresolved(BridgeUnresolvedTypeReference('dart:core', 'Future'), []), false),
            {},
            [],
            {})),
  }, getters: {}, setters: {}, fields: {});
}

eval code

static void evalPiece(String piece) {
    var compiler = Compiler();
    compiler.defineBridgeClasses([OpenApiAsyncBridge.$declaration]);
    final code = "void main() async {\n"
        + "final openApiSyncDebug = OpenApiSyncDebug();\n"
        + "final openApiAsyncDebug = OpenApiAsyncDebug();\n"
        + piece + "\n"
        + "}";
    final program = compiler.compile({
      'package:example': {
        'main.dart': code
      }
    });
    final runtime = Runtime.ofProgram(program);
    runtime.execute(0);
  }

Error Message

Failed to load "/Users/xxxxxx/code/flutter/paas_dashboard_flutter/test/eval/eval_service_test_debug_async_helloworld.dart": Null check operator used on a null value

[ethanblake4]

There are a lot of problems. You are trying to create an OpenApiSyncDebug() but you did not make a bridge declaration for that, you only made it for the OpenApiAsyncDebug. In addition you did not import the library (package:paas_dashboard_flutter/open/open_api_debug_async.dart) in the eval code. Even for the async one you only made the compiler bridge $declaration but it's not a runtime bridge, the OpenApiAsyncBridge needs to extends OpenApiAsyncDebug with $Bridge<OpenApiAsyncDebug> and override the $bridgeGet, $bridgeSet, helloWorld, echo, etc. Also the compiler bridge $declaration needs to have the default constructor, and you need to register the bridge constructor at runtime with runtime.registerBridgeFunc. Finally you should not use runtime.execute(0) but instead runtime.executeNamed(0, 'main').

I would suggest reading the dart_eval_example.dart more carefully, all of these things are correctly done in there.

[ethanblake4]

Converted this to a discussion as it is not a bug or feature request.