How to use the kcd-scripts/config.jest.moduleFileExtensions function in kcd-scripts

const {jest: jestConfig} = require('kcd-scripts/config')

const config = Object.assign(jestConfig, {
  roots: ['tests'],
  testMatch: ['/**/*.spec.js'],
  transform: {
    ...jestConfig.transform,
    '^.+\\.svelte$': 'jest-transform-svelte',
    '^.+\\.html$': 'svelte-test/transform',
  },
  transformIgnorePatterns: [
    ...jestConfig.transformIgnorePatterns,
    '/node_modules/(?!svelte).+\\.js$',
  ],
  moduleFileExtensions: [...jestConfig.moduleFileExtensions, 'svelte'],
})
module.exports = config