FactoryData? createReference()

in functions_framework_builder/lib/src/generic_function_type.dart [74:124]

42 lines of code
7 McCabe index (conditional complexity)


  FactoryData? createReference(
    LibraryElement library,
    String targetName,
    FunctionElement element,
  ) {
    if (element.parameters.isEmpty) {
      return null;
    }

    final firstParamType = element.parameters.first.type;

    final paramInfo = validJsonParamType(firstParamType);

    if (paramInfo == null) {
      return null;
    }

    final returnKind = validJsonReturnType(element.returnType);

    if (returnKind == JsonReturnKind.notJson) {
      return null;
    }

    final functionType = _functionTypeAliasElement.instantiate(
      typeArguments: [firstParamType, element.returnType],
      nullabilitySuffix: NullabilitySuffix.none,
    );

    if (library.typeSystem.isSubtypeOf(element.type, functionType)) {
      if (paramInfo.paramType != null) {
        if (library.exportNamespace.get(paramInfo.paramType!.element.name) ==
            null) {
          // TODO: add a test for this!
          throw InvalidGenerationSourceError(
            'The type `${paramInfo.paramType!.element.name}` is not exposed '
            'by the function library `${library.source.uri}` so it cannot '
            'be used.',
          );
        }
      }

      return _GenericFactoryData(
        _withContext,
        returnKind == JsonReturnKind.isVoid,
        paramInfo,
        escapeDartString(targetName),
        '$functionsLibraryPrefix.${element.name}',
      );
    }
    return null;
  }