src/language-js/loc.js/locStart
function locStart(node, opts) {
  const { ignoreDecorators } = opts || {};

  // Handle nodes with decorators. They should start at the first decorator
  if (!ignoreDecorators) {
    const decorators =
      (node.declaration && node.declaration.decorators) || node.decorators;

    if (isNonEmptyArray(decorators)) {
      return locStart(decorators[0]);
    }
  }

  return node.range ? node.range[0] : node.start;
}