src/language-js/index.js/locStart
const locStart = function(node) {
  // Handle nodes with decorators. They should start at the first decorator
  if (
    node.declaration &&
    node.declaration.decorators &&
    node.declaration.decorators.length > 0
  ) {
    return locStart(node.declaration.decorators[0]);
  }
  if (node.decorators && node.decorators.length > 0) {
    return locStart(node.decorators[0]);
  }

  if (node.__location) {
    return node.__location.startOffset;
  }
  if (node.range) {
    return node.range[0];
  }
  if (typeof node.start === "number") {
    return node.start;
  }
  if (node.loc) {
    return node.loc.start;
  }
  return null;
};