assetgraph/lib/transforms/setAsyncOrDeferOnHtmlScripts.js

An auto discovery dependency graph based optimization framework for web pages and applications

module.exports = (queryObj, setAsyncAttribute, setDeferAttribute) => {
  return function setAsyncOrDeferOnHtmlScripts(assetGraph) {
    if (setAsyncAttribute || setDeferAttribute) {
      for (const htmlScript of assetGraph.findRelations(
        Object.assign({ type: 'HtmlScript' }, queryObj)
      )) {
        if (setAsyncAttribute) {
          htmlScript.node.setAttribute('async', 'async');
        }
        if (setDeferAttribute) {
          htmlScript.node.setAttribute('defer', 'defer');
        }
      }
    }
  };
};