A pure JavaScript implementation of Sasssass. Sass makes CSS fun again.
This package is a distribution of Dart Sass, compiled to pure JavaScript with no native code or external dependencies. It provides a command-line
See the Sass websitejs api for full API documentation.
Sass's support for the legacy JavaScript API has the following limitations:
of Sass. Node Sass supports the same API as this package and is also faster (although it's usually a little slower than Dart Sass). However, it requires a native library which may be difficult to install, and it's generally slower to add features and fix bugs.
This package is a distribution of Dart Sass, compiled to pure JavaScript with no native code or external dependencies. It provides a command-line
sass
executable and a Node.js API.Usage
You can install Sass globally usingnpm install -g sass
which will provide
access to the sass
executable. You can also add it to your project using
npm install --save-dev sass
. This provides the executable as well as a
library:const sass = require('sass');
const result = sass.compile(scssFilename);
// OR
// Note that `compileAsync()` is substantially slower than `compile()`.
const result = await sass.compileAsync(scssFilename);
See the Sass websitejs api for full API documentation.
Legacy API
Dart Sass also supports an older JavaScript API that's fully compatible with Node Sass (with a few exceptions listed below), with support for both therender()
and renderSync()
functions. This API is considered deprecated
and will be removed in Dart Sass 2.0.0, so it should be avoided in new projects.Sass's support for the legacy JavaScript API has the following limitations:
- Only the
"expanded"
and"compressed"
values ofoutputStyle
are
- Dart Sass doesn't support the
precision
option. Dart Sass defaults to a
- Dart Sass doesn't support the
sourceComments
option. Source maps are the
See Also
- Dart Sass, from which this package is compiled, can be used either as a
of Sass. Node Sass supports the same API as this package and is also faster (although it's usually a little slower than Dart Sass). However, it requires a native library which may be difficult to install, and it's generally slower to add features and fix bugs.
Behavioral Differences from Ruby Sass
There are a few intentional behavioral differences between Dart Sass and Ruby Sass. These are generally places where Ruby Sass has an undesired behavior, and it's substantially easier to implement the correct behavior than it would be to implement compatible behavior. These should all have tracking bugs against Ruby Sass to update the reference behavior.@extend
only accepts simple selectors, as does the second argument of
`selector-extend()`. See [issue 1599][].
- Subject selectors are not supported. See issue 1126.
- Pseudo selector arguments are parsed as
<declaration-value>
s rather than
having a more limited custom parsing. See [issue 2120][].
- The numeric precision is set to 10. See issue 1122.
- The indented syntax parser is more flexible: it doesn't require consistent
indentation across the whole document. See [issue 2176][].
- Colors do not support channel-by-channel arithmetic. See issue 2144.
- Unitless numbers aren't
==
to unit numbers with the same value. In
addition, map keys follow the same logic as `==`-equality. See
[issue 1496][].
rgba()
andhsla()
alpha values with percentage units are interpreted as
percentages. Other units are forbidden. See [issue 1525][].
- Too many variable arguments passed to a function is an error. See
[issue 1408][].
- Allow
@extend
to reach outside a media query if there's an identical
`@extend` defined outside that query. This isn't tracked explicitly, because
it'll be irrelevant when [issue 1050][] is fixed.
- Some selector pseudos containing placeholder selectors will be compiled
where they wouldn't be in Ruby Sass. This better matches the semantics of
the selectors in question, and is more efficient. See [issue 2228][].
- The old-style
:property value
syntax is not supported in the indented
syntax. See [issue 2245][].
- The reference combinator is not supported. See issue 303.
- Universal selector unification is symmetrical. See issue 2247.
@extend
doesn't produce an error if it matches but fails to unify. See
[issue 2250][].
- Dart Sass currently only supports UTF-8 documents. We'd like to support
more, but Dart currently doesn't support them. See [dart-lang/sdk#11744][],
for example.
Disclaimer: this is not an official Google product.