babel-transformer.js

const { createTransformer } = require('babel-jest');

const config = {
  presets: [
    [
      '@babel/preset-env',
      {
        targets: { node: 'current' },
      },
    ],
    '@babel/preset-typescript',
  ],
  plugins: [
    '@babel/plugin-proposal-object-rest-spread',
    '@babel/plugin-proposal-class-properties',
    '@babel/plugin-proposal-export-default-from',
    '@babel/plugin-proposal-export-namespace-from',
    '@babel/plugin-transform-async-to-generator',
    '@babel/plugin-proposal-async-generator-functions',
    '@babel/plugin-proposal-nullish-coalescing-operator',
    '@babel/plugin-proposal-optional-chaining',
  ],
};

module.exports = createTransformer(config);