function transformCode(code, url, options) {
  try {
    var transformed = transformReact(code, options);
  } catch(e) {
    e.message += '\n    at ';
    if (url) {
      if ('fileName' in e) {
        // We set `fileName` if it's supported by this error object and
        // a `url` was provided.
        // The error will correctly point to `url` in Firefox.
        e.fileName = url;
      }
      e.message += url + ':' + e.lineNumber + ':' + e.columnNumber;
    } else {
      e.message += location.href;
    }
    e.message += createSourceCodeErrorMessage(code, e);
    throw e;
  }

  if (!transformed.sourceMap) {
    return transformed.code;
  }

  var source;
  if (url == null) {
    source = 'Inline JSX script';
    inlineScriptCount++;
    if (inlineScriptCount > 1) {
      source += ' (' + inlineScriptCount + ')';
    }
  } else if (dummyAnchor) {
    // Firefox has problems when the sourcemap source is a proper URL with a
    // protocol and hostname, so use the pathname. We could use just the
    // filename, but hopefully using the full path will prevent potential
    // issues where the same filename exists in multiple directories.
    dummyAnchor.href = url;
    source = dummyAnchor.pathname.substr(1);
  }

  return (
    transformed.code +
    '\n' +
    inlineSourceMap(transformed.sourceMap, code, source)
  );
}
Actually transform the code.

@param {string} code
@param {string?} url
@param {object?} options
@return {string} The transformed code.
@internal