import * as CleanCSS from 'clean-css' ; /**
 * CSS Transformer
 */ export class CSSTransformer { param cssContent returns public static minify ( cssContent ) { if ( cssContent . trim ( ) === '' ) { return '' ; } else { const minified = new CleanCSS ( < any > { level : 0 } ) . minify ( cssContent ) ; if ( minified . errors . length > 0 ) { throw new Error ( `CSS Minifier: ${ minified . errors . join ( '\n' ) }` ) ; } return minified . styles ; } } }