build/lib/src/builder/file_deleting_builder.dart

// Copyright (c) 2018, 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.

import 'dart:async';

import 'package:glob/glob.dart';

import 'post_process_build_step.dart';
import 'post_process_builder.dart';

/// A [PostProcessBuilder] which can be configured to consume any input
/// extensions and always deletes it primary input.
class FileDeletingBuilder implements PostProcessBuilder {
  @override
  final List<String> inputExtensions;

  final bool isEnabled;
  final List<Glob> exclude;

  const FileDeletingBuilder(this.inputExtensions, {this.isEnabled = true})
      : exclude = const [];

  FileDeletingBuilder.withExcludes(
      this.inputExtensions, Iterable<String> exclude,
      {this.isEnabled = true})
      : exclude = exclude?.map((s) => Glob(s))?.toList() ?? const [];

  @override
  FutureOr<Null> build(PostProcessBuildStep buildStep) {
    if (!isEnabled) return null;
    if (exclude.any((g) => g.matches(buildStep.inputId.path))) return null;
    buildStep.deletePrimaryInput();
    return null;
  }
}