const regex = /<(script)([^\/>]*?)>((\s|.)*?)<\/script\s?>/gim;
// Alternative syntax using RegExp constructor
// const regex = new RegExp('<(script)([^\\\/>]*?)>((\\s|.)*?)<\\\/script\\s?>', 'gim')
const str = `<script type=3D"text/javascript">hsjQuery =3D window['jQuery']</script>
<script type=3D"textjavascript">hsjQuery = 1 / 2</script>
<script type=3D"text/javascript"/>hsjQuery = 1 / 2</script>
<script type="textjavascript">asdgsdgs</script>
<script />
<script>lala</script>`;
const subst = `<ff-$1 style='display: none;'$2>$3</ff-$1>`;
// The substituted value will be contained in the result variable
const result = str.replace(regex, subst);
console.log('Substitution result: ', result);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for JavaScript, please visit: https://developer.mozilla.org/en/docs/Web/JavaScript/Guide/Regular_Expressions