src/config/resolve-config.js/mergeOverrides
function mergeOverrides(configResult, filePath) {
  const options = Object.assign({}, configResult.config);
  if (filePath && options.overrides) {
    const relativeFilePath = path.relative(
      path.dirname(configResult.filepath),
      filePath
    );
    for (const override of options.overrides) {
      if (
        pathMatchesGlobs(
          relativeFilePath,
          override.files,
          override.excludeFiles
        )
      ) {
        Object.assign(options, override.options);
      }
    }
  }

  delete options.overrides;
  return options;
}