anchor.diff:          expression = "${parent.name}()";
         }
       } else {
  -      print("Ignoring $m (${m.runtimeType})");
  -      return;
  +      throw "Didn't know ${m.runtimeType}";
       }
   
       String? className;
  
positive.code:             "${errors.map((e) => e.plainTextFormatted.first).toList()}");
        }
        Uri dillFileUri = toTestUri("${test.description.shortName}.dill");
        Uint8List dillData = await serializeComponent(component);
        context.fileSystem.entityForUri(dillFileUri).writeAsBytesSync(dillData);
        Set<Uri> beforeFuzzedLibraries = context.fuzzedLibraries.toSet();
        await compileExpression(
            test, sourceCompiler, sourceCompilerResult, context);
  
        IncrementalCompiler dillCompiler =
            new IncrementalCompiler(context.compilerContext, dillFileUri);
  
negative.code:       // Since it compiled successfully from source, the bootstrap-from-Dill
        // should also succeed without errors.
        assert(errors.isEmpty);
  
        IncrementalCompiler? dillCompilerNoNNBD;
        if (context.fuzz) {
          dillCompilerNoNNBD = new IncrementalCompiler(
              context.compilerContextNoNNBD, dillFileNoNNBDUri);
          IncrementalCompilerResult dillCompilerNoNNBDResult =
              await dillCompilerNoNNBD
                  .computeDelta(entryPoints: [test.entryPoint]);
          Component componentNoNNBD = dillCompilerNoNNBDResult.component;
          componentNoNNBD.computeCanonicalNames();
          context.takeErrors();
        }
  
        context.fuzzedLibraries.clear();
        context.fuzzedLibraries.addAll(beforeFuzzedLibraries);
        await compileExpression(
            test, dillCompiler, dillCompilerNoNNBD, dillCompilerResult, context);
      }
      return new Result.pass(tests);
    }
  