this version will run with npm start, but when attempting to run the built version behind nginx, it appears to have issues
regjsgen

Generate regular expressions from regjsparser’s AST.
Installation
npm i regjsgen
API
regjsgen.generate(ast)
This function accepts an abstract syntax tree representing a regular expression (see regjsparser), and returns the generated regular expression string.
const regjsparser = require('regjsparser');
const regjsgen = require('regjsgen');
// Generate an AST with `regjsparser`.
let ast = regjsparser.parse(regex);
// Modify AST
// …
// Generate `RegExp` string with `regjsgen`.
let regex = regjsgen.generate(ast);
Support
Tested in Node.js 0.10, 0.12, 4, 6, 8, 10, 12 and 14.
Compatible with regjsparser v0.6.4’s AST.