Cross Platform Paths

1// Copyright (c) 2026, the Dart project authors. Please see the AUTHORS file
2// for details. All rights reserved. Use of this source code is governed by a
3// BSD-style license that can be found in the LICENSE file.
4
5import 'dart:io';
6
7import 'package:path/path.dart' as p;
8
9/// Checks if [file] resides inside a 'canvaskit' directory and has a '.wasm' extension.
10bool isCanvasKitWasmAsset(File file) {
11  final segments = p.split(file.path);
12  return segments.contains('canvaskit') && p.extension(file.path) == '.wasm';
13}
14
15/// Converts an OS-native file path into a POSIX-style web asset key.
16String computeWebAssetKey(String filePath, String projectRoot) {
17  final relative = p.relative(filePath, from: projectRoot);
18  final segments = p.split(relative);
19  return switch (segments) {
20    ['assets', ...] => p.posix.joinAll(segments),
21    _ => p.posix.joinAll(['assets', ...segments]),
22  };
23}
24
25/// Inserts a content hash before file extensions, safely handling compound
26/// extensions (e.g. '.js.map') versus multi-dot stems (e.g. 'main.dart.wasm').
27String insertContentHash(String filename, String hash) {
28  final compoundExt = p.extension(filename, 2);
29  final ext = compoundExt.endsWith('.map')
30      ? compoundExt
31      : p.extension(filename);
32  final stem = filename.substring(0, filename.length - ext.length);
33  return '$stem.$hash$ext';
34}
35
36/// Converts an OS-native relative path to a POSIX path suitable for
37/// `.gitignore`, `.gitattributes`, or Git tree objects.
38String toGitPath(String relativeNativePath) =>
39    p.posix.joinAll(p.split(relativeNativePath));
40
41void main() {
42  print('Git path: ${toGitPath(r'lib\src\file.dart')}');
43  print('Asset key: ${computeWebAssetKey('assets/icon.png', '.')}');
44  print('Content hash: ${insertContentHash('main.dart.js.map', 'a1b2c3')}');
45}