svelte-preprocess-sass

Svelte preprocessor for sass

Installation

npm install --save-dev svelte-preprocess-sass sass

Usage

Using rollup-plugin-svelte

// rollup.config.js
import svelte from 'rollup-plugin-svelte';
import { sass } from 'svelte-preprocess-sass';
...

export default {
  ...
  plugins: [
    ...
    svelte({
      preprocess: {
        style: sass(),
      },
    }),
  ],
};

Now all <style> elements in your components that have a type="text/sass" or lang="sass" attribute will be preprocessed by sass.

<style type="text/sass">
  $primary: red

  button
    color: $primary
</style>

<button on:click>Click me</button>

Using SCSS

...just use type="text/scss" or lang="scss" in your components:

<style type="text/scss">
  $primary: red;

  button {
    color: $primary;
  }
</style>

<button on:click>Click me</button>

// rollup.config.js
import svelte from 'rollup-plugin-svelte';
import { sass } from 'svelte-preprocess-sass';
...

export default {
  ...
  plugins: [
    ...
    svelte({
      preprocess: {
        style: sass({}, { name: 'scss' }),
      },
    }),
  ],
};

Passing options to sass

The sass function passes the first argument to the sass compiler, e.g.:

...
sass({
  plugins: [
    ...
  ]
})

Common options:

• Allow imports from node_modules via the includePaths option:

  import { join } from 'path';
  import svelte from 'rollup-plugin-svelte';
  import { sass } from 'svelte-preprocess-sass';
  
  export default {
    ...
    plugins: [
      ...
      svelte({
        preprocess: {
          style: sass({
            includePaths: [
              // Allow imports from 'node_modules'
              join(__dirname, 'node_modules'),
            ]
          }),
        },
      }),
    ],
  };

For available options visit the sass and dart-sass docs.

Filtering styles

The sass function passes the second argument to svelte-preprocess-filter, e.g.:

...
sass(
  {}, // Empty sass options
  { all: true } // Preprocess all styles
)

Creating component libraries

Take a look at the LukasHechenberger/sample-svelte-scss-lib repository for an example of how to create component libraries with extendable styles. (Discussed in #95)