config-overrides.js

module.exports = function override(config, env) {
  // NOTE: The current version of react-scripts-ts does not support yarn/lerna workspaces.
  // As we're using TypeScript source code from a different module the TypeScript compilation can't locate source files outside of the current module,
  // due to the fact that webpack is responsible for compiling TypeScript. The webpack config is "protected" as it's a part of the react-scripts-ts package.
  // In short this hack find the ts-loader from the webpack config and removes the "include" property from the webpack ts-loader config.
  // We do this hack to avoid having to eject the project from create-react-app or having to fork the react-script-ts repository and remove one line of code.
  config.module.rules = config.module.rules.map(rule => {
    var isOneOf = Object.keys(rule).findIndex(key => key === "oneOf") === 0;

    if (isOneOf) {
      var oneOf = rule.oneOf;
      var indexOfTs = oneOf.findIndex(function(r) {
        return String(r.test) === String(/\.(ts|tsx)$/);
      });
      var oldTsRule = oneOf[indexOfTs];
      var tsRule = Object.assign(
        {},
        {
          test: oldTsRule.test,
          use: oldTsRule.use
        }
      );

      var newOneOf = [].concat(
        oneOf.slice(0, indexOfTs),
        tsRule,
        oneOf.slice(indexOfTs + 1, oneOf.length)
      );

      rule.oneOf = newOneOf;
    }

    return rule;
  });
  return config;
};