node-jsx-loader.js

import babel from "@babel/core";

const babelOptions = {
  babelrc: false,
  ignore: [/\/(build|node_modules)\//],
  plugins: [["@babel/plugin-transform-react-jsx", { runtime: "automatic" }]],
};

export async function load(url, context, defaultLoad) {
  const result = await defaultLoad(url, context, defaultLoad);
  if (result.format === "module") {
    const opt = Object.assign({ filename: url }, babelOptions);
    const newResult = await babel.transformAsync(result.source, opt);
    if (!newResult) {
      if (typeof result.source === "string") {
        return result;
      }
      return {
        source: Buffer.from(result.source).toString("utf8"),
        format: "module",
      };
    }
    return { source: newResult.code, format: "module" };
  }
  return defaultLoad(url, context, defaultLoad);
}