pkgs/blast_repo/lib/src/exact_file_tweak.dart

// Copyright (c) 2022, 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 'dart:io';

import 'package:path/path.dart' as p;

import 'repo_tweak.dart';

abstract class ExactFileTweak extends RepoTweak {
  ExactFileTweak({
    required this.filePath,
    required super.id,
    required super.description,
    this.alternateFilePaths = const {},
  }) : assert(p.isRelative(filePath)) {
    if (!p.isRelative(filePath)) {
      throw ArgumentError.value(
        filePath,
        'filePath',
        'Must be a relative path!',
      );
    }

    for (var entry in alternateFilePaths) {
      if (p.equals(entry, filePath)) {
        throw ArgumentError.value(
          alternateFilePaths,
          'alternateFilePaths',
          'Should not contain `filePath` ($filePath).',
        );
      }
      if (!p.isRelative(entry)) {
        throw ArgumentError.value(
          alternateFilePaths,
          'alternateFilePaths',
          'Must be a relative path ($entry)',
        );
      }
    }
  }

  final String filePath;
  final Set<String> alternateFilePaths;

  String expectedContent(Directory checkout, String repoSlug);

  @override
  FutureOr<FixResult> fix(Directory checkout, String repoSlug) {
    final file = _targetFile(checkout);

    var fixResults = <String>[];

    final newContent = expectedContent(checkout, repoSlug);
    if (!file.existsSync()) {
      file.writeAsStringSync(newContent);
      fixResults.add('$filePath has been created.');
    } else if (file.readAsStringSync() != newContent) {
      file.writeAsStringSync(newContent);
      fixResults.add('$filePath has been updated.');
    }

    return fixResults.isEmpty
        ? FixResult.noFixesMade
        : FixResult(fixes: fixResults);
  }

  File _targetFile(Directory checkout) {
    assert(checkout.existsSync());

    for (var option in [filePath, ...alternateFilePaths]) {
      final realPath = p.join(checkout.path, option);

      final realFile = File(realPath);
      if (realFile.existsSync()) {
        return realFile;
      }
    }

    return File(p.join(checkout.path, filePath));
  }
}