重大变化：错误放置的剩余参数

Sass 历来允许剩余参数出现在参数列表的任何位置，即使它们总是在末尾求值。这堵住了这个漏洞，并要求剩余参数出现在参数列表的末尾。

Dart Sass: since 1.91.0
LibSass: ✗
Ruby Sass: ✗

Sass 中的剩余参数（写作 $args...）始终旨在写在参数列表的末尾。它们的求值方式反映了这一点：它们总是被添加到位置参数列表的末尾。

¥Rest arguments in Sass (written $args...) were always intended to be written at the end of argument lists. The way they’re evaluated reflects this: they’re always run after all the other arguments, and they’re always added to the end of the list of positional arguments.

但是，由于 Ruby Sass 和 Dart Sass 实现过程中的疏忽，此规定从未得到执行。之前可以编写类似 rgb([1, 2]..., 3) 的函数调用，将剩余参数放在位置（或命名）参数之前。但这看起来并不适用：它与 rgb(3, [1, 2]...) 的解析方式相同，并生成颜色值 rgb(3, 1, 2)。

¥However, due to an oversight in the implementation of both Ruby Sass and Dart Sass, this was never enforced. It was possible to write a function call like rgb([1, 2]..., 3) with the rest argument before a positional (or named) argument. This didn’t work how it looks, though: it was parsed the same as rgb(3, [1, 2]...) and resulted in the color value rgb(3, 1, 2).

💡 Fun fact:

请注意，@function 和 @mixin 规则中的参数声明始终要求剩余参数出现在末尾。它们不受此弃用的影响。

¥Note that parameter declarations in the @function and @mixin rules have always required rest parameters to appear at the end. They aren’t affected by this deprecation.

为了消除这种混淆，并可能在未来为剩余参数提供更合理的行为支持，我们将分多个阶段进行更改：

¥To eliminate this confusion and potentially open a path towards supporting more sensible behavior for rest arguments in the future, we’re making changes in multiple phases:

阶段 1阶段 1 permalink

¥Phase 1

Dart Sass: since 1.91.0
LibSass: ✗
Ruby Sass: ✗

目前，如果在参数列表末尾以外的任何位置使用剩余参数，Dart Sass 都会发出弃用警告。

¥Currently, Dart Sass emits a deprecation warning if you use a rest argument anywhere other than at the end of an argument list.

要修复任何违规行为并保留现有行为，只需将剩余参数移至参数列表的末尾即可。不过，你可能需要检查一下，确保你最初编写代码时没有预料到它会执行与实际不同的操作！

¥To fix any violations and preserve the existing behavior, just move the rest argument to the end of the argument list. You might want to check to make sure that you weren’t expecting it to do something different than it actually does when you first wrote the code, though!

阶段 2阶段 2 permalink

¥Phase 2

Dart Sass: ✗
LibSass: ✗
Ruby Sass: ✗

在 Dart Sass 2.0.0 中，在参数列表末尾以外的任何位置使用剩余参数将导致语法错误。

¥In Dart Sass 2.0.0, using a rest argument anywhere other than at the end of an argument list will be a syntax error.

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.

⚠️ Heads up!

When running from the JS API, Sass doesn’t share any information across compilations, so by default it’ll print five warnings for each stylesheet that’s compiled. However, you can fix this by writing (or asking the author of your favorite framework’s Sass plugin to write) a custom Logger that only prints five errors per deprecation and can be shared across multiple compilations.

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.