pkg/front_end/lib/src/builder/invalid_builder.dart

// Copyright (c) 2016, the Dart project authors.  Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.

part of 'declaration_builders.dart';

/// [InvalidBuilder] encapsulates an erroneous state as [Builder].
///
/// If [errorHasBeenReported] is `true`, the message has already been reported.
/// Otherwise the [message] must be reported upon use.
///
/// This builder implements both [TypeDeclarationBuilder] and [MemberBuilder]
/// so that it can be used both in types and in member lookups.
class InvalidBuilder extends TypeDeclarationBuilderImpl
    with ErroneousMemberBuilderMixin
    implements TypeDeclarationBuilder {
  @override
  final String name;

  final LocatedMessage message;

  final List<LocatedMessage>? context;

  final bool errorHasBeenReported;

  InvalidBuilder(
    this.name,
    this.message, {
    this.context,
    this.errorHasBeenReported = true,
  });

  @override
  int get typeParametersCount => 0;

  @override
  Builder? get parent => null;

  @override
  // Coverage-ignore(suite): Not run.
  int get fileOffset => message.charOffset;

  @override
  // Coverage-ignore(suite): Not run.
  Uri get fileUri => message.uri!;

  @override
  DartType buildAliasedType(
    LibraryBuilder library,
    NullabilityBuilder nullabilityBuilder,
    List<TypeBuilder>? arguments,
    TypeUse typeUse,
    Uri fileUri,
    int charOffset,
    ClassHierarchyBase? hierarchy, {
    required bool hasExplicitTypeArguments,
  }) {
    return buildAliasedTypeWithBuiltArguments(
      library,
      null,
      null,
      typeUse,
      fileUri,
      charOffset,
      hasExplicitTypeArguments: hasExplicitTypeArguments,
    );
  }

  /// [Arguments] have already been built.
  @override
  DartType buildAliasedTypeWithBuiltArguments(
    LibraryBuilder library,
    Nullability? nullability,
    List<DartType>? arguments,
    TypeUse typeUse,
    Uri fileUri,
    int charOffset, {
    required bool hasExplicitTypeArguments,
  }) {
    if (!errorHasBeenReported) {
      library.addProblem(
        message.messageObject,
        message.charOffset,
        message.length,
        message.uri,
        context: context,
      );
    }
    return const InvalidType();
  }

  @override
  Nullability computeNullabilityWithArguments(
    List<TypeBuilder>? typeArguments, {
    required Map<TypeParameterBuilder, TraversalState>
    typeParametersTraversalState,
  }) {
    // TODO(johnniwinther,cstefantsova): Consider implementing
    // invalidNullability.
    return Nullability.nullable;
  }

  @override
  // TODO(johnniwinther): This should probably return `null`.
  MemberBuilder get getable => this;

  @override
  MemberBuilder? get setable => null;
}