clean-css-batch-promise

let CleanCSS = require('clean-css'); (async () => { try { let cleanCSS = new CleanCSS({ batch: true, returnPromise: true, }); let outputs = await cleanCSS.minify([ {'path/to/file/one': {styles: 'html { color: #000000; }'}}, {'path/to/file/two': {styles: 'body { background: #ffffff; }'}} ]); console.log("OK", outputs); } catch (e) { console.log("error", e); } })();