重大变化：`@import` 和全局内置函数

@import 会导致许多问题，需要手动为 Sass 成员指定命名空间以避免冲突，当多次导入同一个文件时会减慢编译速度，并且使人类和工具都很难分辨给定变量、混合或函数来自何处。

¥@import causes numerous problems, requiring Sass members to be manually namespaced to avoid conflicts, slowing down compilation when the same file is imported more than once, and making it very difficult for both humans and tools to tell where a given variable, mixin, or function comes from.

模块系统修复了这些问题，并使 Sass 的模块化与其他现代语言的最佳实践相媲美，但只要 @import 仍保留在语言中，我们就无法获得它的全部好处。

¥The module system fixes these problems and brings Sass’s modularity up to par with the best practices of other modern languages, but we can’t get the full benefits of it while @import remains in the language.

@import 现在从 Dart Sass 1.80.0 开始已弃用。此外，我们还将弃用 sass: 模块中可用的 Sass 内置函数的全局版本。

¥@import is now deprecated as of Dart Sass 1.80.0. Additionally, we’re also deprecating the global versions of Sass built-in functions that are available in sass: modules.

过渡期过渡期 permalink

¥Transition Period

兼容性:

Dart Sass

since 1.80.0

LibSass

✗

Ruby Sass

✗

Sass @import 规则和全局内置函数调用现在会发出弃用警告。虽然 Dart Sass 2.0.0 即将发布，其中包含各种较小的重大更改，但我们预计直到 Dart Sass 3.0.0 才会删除 Sass @import 规则或全局内置函数，而 Dart Sass 3.0.0 将在 Dart Sass 1.80.0 发布两年后发布。

¥Sass @import rules and global built-in function calls now emit deprecation warnings. While Dart Sass 2.0.0 will be released soon with various smaller breaking changes, we don’t expect to remove Sass @import rules or global built-in functions until Dart Sass 3.0.0, which will be released no sooner than two years after Dart Sass 1.80.0.

最终，所有 @import 规则都将被视为 纯 CSS @import，可能在中间时期之后，任何曾经是 Sass @import 的东西都会引发错误。

¥Eventually, all @import rules will be treated as plain CSS @imports, likely after an intermediate period where anything that used to be a Sass @import throws an error.

自动迁移自动迁移 permalink

¥Automatic Migration

你可以使用 Sass 迁移器 自动更新样式表以使用模块系统。

¥You can use the Sass migrator to automatically update your stylesheets to use the module system.

$ npm install -g sass-migrator
$ sass-migrator module --migrate-deps your-entrypoint.scss

如果你想要迁移全局内置函数，但尚未准备好完全迁移 @import 规则，则可以传递 --built-in-only 标志来迁移函数，同时保留 @import 规则。

¥If you want to migrate away from global built-in functions, but aren’t yet ready to fully migrate your @import rules, you can pass the --built-in-only flag to migrate the functions while leaving @import rules as-is.

Can I Silence the Warnings?Can I Silence the Warnings? permalink

Sass provides a powerful suite of options for managing which deprecation warnings you see and when.

Terse and Verbose ModeTerse and Verbose Mode permalink

By default, Sass runs in terse mode, where it will only print each type of deprecation warning five times before it silences additional warnings. This helps ensure that users know when they need to be aware of an upcoming breaking change without creating an overwhelming amount of console noise.

If you run Sass in verbose mode instead, it will print every deprecation warning it encounters. This can be useful for tracking the remaining work to be done when fixing deprecations. You can enable verbose mode using the --verbose flag on the command line, or the verbose option in the JavaScript API.

Silencing Deprecations in DependenciesSilencing Deprecations in Dependencies permalink

Sometimes, your dependencies have deprecation warnings that you can’t do anything about. You can silence deprecation warnings from dependencies while still printing them for your app using the --quiet-deps flag on the command line, or the quietDeps option in the JavaScript API.

For the purposes of this flag, a "dependency" is any stylesheet that’s not just a series of relative loads from the entrypoint stylesheet. This means anything that comes from a load path, and most stylesheets loaded through custom importers.

Silencing Specific DeprecationsSilencing Specific Deprecations permalink

If you know that one particular deprecation isn’t a problem for you, you can silence warnings for that specific deprecation using the --silence-deprecation flag on the command line, or the silenceDeprecations option in the JavaScript API.

注意：虽然 @import 和全局内置函数的弃用将一起发布，并且我们预计这两个功能也将同时被删除（在 Dart Sass 3.0.0 中），但就 API 而言，它们被视为单独的弃用。如果你希望同时消除 @import 弃用警告和全局内置弃用警告，则需要将 import 和 global-builtin 都传递给 --silence-deprecation/silenceDeprecations。

¥Note: While the deprecations for @import and global built-ins are being released together and we expect both features to be removed simultaneously as well (in Dart Sass 3.0.0), they are considered separate deprecations for the purpose of the API. If you wish to silence both @import deprecation warnings and global built-in deprecation warnings, you’ll need to pass both import and global-builtin to --silence-deprecation/silenceDeprecations.