preprocessor script for using Jest testing framework on Angular projects

preprocessor.js

const process = require('ts-jest/preprocessor.js').process;
const TEMPLATE_URL_REGEX = /templateUrl:\s*('|")(\.\/){0,}(.*)('|")/g;
const STYLE_URLS_REGEX = /style(Url)?s:\s*\[\s*(require\()?((?:'|").*\s*(?:'|")\)?).*\s*.*\]/g;
const ESCAPE_TEMPLATE_REGEX = /(\${|\`)/g;

module.exports.process = function (src, path, config, transformOptions) {
  
  if (path.endsWith('.html')) {
    console.log('preprocessing ' + path);
    src = src.replace(ESCAPE_TEMPLATE_REGEX, '\\$1');
  }

  if (path.endsWith('.ts')) {
    console.log('preprocessing ' + path);
    src = src
      .replace(TEMPLATE_URL_REGEX, 'template: require($1./$3$4)')
      .replace(STYLE_URLS_REGEX, 'styles: []');
  }

  return process(src, path, config, transformOptions);
};