Using a library that uses Nullish Coalescing operator (??) breaks Storybook build

[fernandes77]

Storybook doesn't work when we add a library (in this case, react-facade) that uses the Nullish Coalescing operator ?? added in TypeScript 3.7.

Here's a screenshot of the error:

[fernandes77]

Here's a fix: specify a loader on webpack config:

module.exports = async ({ config, mode }) => {
  config.module.rules.push({
    test: /\.(mjs|jsx?)$/,
    loader: 'esbuild-loader'
  });

  return config;
};

We chose esbuild-loader which is faster than babel-loader but either one works.