List _checkFunction()

in lib/src/builder.dart [638:697]
53 lines of code
13 McCabe index (conditional complexity)

  List<String> _checkFunction(
    analyzer.FunctionType function,
    Element enclosingElement, {
    bool isParameter = false,
    bool hasDummyGenerator = false,
  }) {
    final errorMessages = <String>[];
    final returnType = function.returnType;
    if (returnType is analyzer.InterfaceType) {
      if (returnType.element.isPrivate) {
        errorMessages.add(
            '${enclosingElement.fullName} features a private return type, and '
            'cannot be stubbed.');
      }
      errorMessages.addAll(
          _checkTypeArguments(returnType.typeArguments, enclosingElement));
    } else if (returnType is analyzer.FunctionType) {
      errorMessages.addAll(_checkFunction(returnType, enclosingElement));
    } else if (returnType is analyzer.TypeParameterType) {
      if (!isParameter &&
          !hasDummyGenerator &&
          _entryLib.typeSystem.isPotentiallyNonNullable(returnType)) {
        errorMessages
            .add('${enclosingElement.fullName} features a non-nullable unknown '
                'return type, and cannot be stubbed without a dummy generator '
                'specified on the MockSpec.');
      }
    }

    for (var parameter in function.parameters) {
      var parameterType = parameter.type;
      if (parameterType is analyzer.InterfaceType) {
        var parameterTypeElement = parameterType.element;
        if (parameterTypeElement.isPrivate) {
          // Technically, we can expand the type in the mock to something like
          // `Object?`. However, until there is a decent use case, we will not
          // generate such a mock.
          errorMessages.add(
              '${enclosingElement.fullName} features a private parameter type, '
              "'${parameterTypeElement.name}', and cannot be stubbed.");
        }
        errorMessages.addAll(
            _checkTypeArguments(parameterType.typeArguments, enclosingElement));
      } else if (parameterType is analyzer.FunctionType) {
        errorMessages.addAll(
            _checkFunction(parameterType, enclosingElement, isParameter: true));
      }
    }

    errorMessages
        .addAll(_checkTypeParameters(function.typeFormals, enclosingElement));

    var aliasArguments = function.alias?.typeArguments;
    if (aliasArguments != null) {
      errorMessages
          .addAll(_checkTypeArguments(aliasArguments, enclosingElement));
    }

    return errorMessages;
  }