重大变更：混合声明
CSS 正在改变处理混合嵌套规则和声明的方式，我们希望确保 Sass 与其行为相匹配。
目前的情况目前的情况 permalink
历史上，如果在 Sass 中混合嵌套规则和声明，它会将所有声明移到规则的开头，以避免不必要地重复外部选择器。例如：
Playground
SCSS Syntax
.example {
color: red;
&--serious {
font-weight: bold;
}
font-weight: normal;
}
CSS Output
.example {
color: red;
font-weight: normal;
}
.example--serious {
font-weight: bold;
}
当最初引入纯 CSS 嵌套时，它的行为相同。然而，经过深思熟虑后，CSS 工作组决定让声明按照它们在文档中出现的顺序应用更有意义，如下所示：
Playground
SCSS Syntax
.example {
color: red;
&--serious {
font-weight: bold;
}
font-weight: normal;
}
CSS Output
.example {
color: red;
}
.example--serious {
font-weight: bold;
}
.example {
font-weight: normal;
}
弃用旧方式弃用旧方式 permalink
- Dart Sass
- since 1.77.7
- LibSass
- ✗
- Ruby Sass
- ✗
目前在 Sass 中，在嵌套规则之后使用声明已被弃用，以便通知用户即将到来的变更并给他们时间使其样式表兼容。在未来的版本中，Dart Sass 将更改为匹配纯 CSS 嵌套产生的排序。
如果你想提前选择新的 CSS 语义，可以将嵌套声明包装在 & {} 中：
Playground
SCSS Syntax
.example {
color: red;
&--serious {
font-weight: bold;
}
& {
font-weight: normal;
}
}
CSS Output
.example {
color: red;
}
.example--serious {
font-weight: bold;
}
.example {
font-weight: normal;
}
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.