重大变化：以 – 开头的函数和混合

通常，Sass 允许任何有效的 CSS 标识符用于任何 Sass 定义。这包括以 -- 开头的标识符，用户可能在 CSS 自定义属性 的上下文中最熟悉这些标识符。但是，CSS 工作组正在 认真考虑 为 CSS 本身添加对函数和 mixin 的内置支持，可能使用名为 @mixin 和 @function 的 at-rules，就像 Sass 一样。

¥Generally, Sass allows any valid CSS identifier to be used for any Sass definition. This includes identifiers which begin with --, which users may be most familiar with in the context of CSS custom properties. However, the CSS working group is seriously considering adding built-in support to CSS itself for functions and mixins, likely using at-rules named @mixin and @function just like Sass.

这意味着，为了在仍然支持 Sass 的构建时函数和 mixin 的同时保留其 CSS 兼容性的核心设计原则，Sass 需要能够区分使用相同 at-rule 名称的 CSS 和 Sass 声明。幸运的是，尽管 CSS 用于函数和 mixin 的语法细节仍悬而未决，但有一点似乎没有争议：使用以 -- 开头的自定义属性类标识符作为 CSS 混合和函数名称。

¥This means that Sass, in order to preserve its core design principle of CSS compatibility while still supporting Sass’s build-time functions and mixins, needs to be able to distinguish between CSS and Sass declarations that use the same at-rule names. Fortunately, although the details of the syntax CSS uses for functions and mixins is still very much up in the air, one point seems uncontroversial: the use of custom-property-like identifiers beginning with -- for CSS mixin and function names.

这将允许 Sass 将纯 CSS 函数和混合与以 -- 开头的函数和混合区分开来。但为了使其正常工作，我们首先必须禁止 Sass 函数和 mixin 使用该前缀。

¥This will allow Sass to distinguish plain-CSS functions and mixins as those that begin with --. But in order for this to work, we first have to disallow Sass functions and mixins from using that prefix.

过渡期过渡期 permalink

¥Transition Period

兼容性:

Dart Sass

since 1.76.0

LibSass

✗

Ruby Sass

✗

在 Dart Sass 1.76.0 和 Dart Sass 2.0.0 之间，Dart Sass 将继续允许名称以 -- 开头的函数和 mixin。但是，它会发出一个名为 css-function-mixin 的弃用警告。

¥Between Dart Sass 1.76.0 and Dart Sass 2.0.0, Dart Sass will continue to allow functions and mixins whose names begin with --. However, it will emit a deprecation warning named css-function-mixin.

在 Dart Sass 2.0.0 和 Dart Sass 对纯 CSS 函数和 mixin 的支持发布之间，函数和 mixin 将不允许使用以 -- 开头的名称。

¥Between Dart Sass 2.0.0 and the release of Dart Sass’s support for plain CSS functions and mixins, functions and mixins will not be allowed to have names that begin with --.

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.