node-sass

Compiling SCSS to CSS

This feature allows you to compile .scss files into .css files. The 'render' method takes an options object and a callback function. The options object specifies the input and output paths for the SCSS and CSS files, respectively. The callback is invoked after the compilation process, and you can handle the result or error accordingly.

const sass = require('node-sass');
sass.render({
  file: 'path/to/input.scss',
  outFile: 'path/to/output.css'
}, function(error, result) { // Node-style callback from v3.0.0 onwards
  if(!error){
    // No errors during the compilation, write this result on the disk
    fs.writeFile('path/to/output.css', result.css, function(err){
      if(!err){
        //file written on disk
      }
    });
  }
});

Watching files or directories

This feature allows you to watch .scss files or directories for changes and automatically recompile them to CSS when a change is detected. The example uses 'chokidar', an external library for watching files, to listen for changes on the specified SCSS file and then uses node-sass to compile the file to CSS.

const sass = require('node-sass');
const chokidar = require('chokidar');

chokidar.watch('path/to/input.scss').on('change', () => {
  sass.render({
    file: 'path/to/input.scss',
    outFile: 'path/to/output.css'
  }, function(error, result) {
    if (!error) {
      fs.writeFile('path/to/output.css', result.css, function(err){
        if(!err){
          console.log('SCSS file updated.');
        }
      });
    }
  });
});

Command Line Interface (CLI) usage

node-sass provides a CLI for compiling SCSS files to CSS directly from the command line. In this example, the '--output-style' option is used to specify the CSS output format (compressed in this case), '-o' is used to define the output directory for the compiled CSS, and the last argument is the input directory containing the SCSS files.

node-sass --output-style compressed -o dist/css src/scss