code: function decodeDataUrlFromQueryParam(value) {
    if (typeof value !== 'string') {
      return undefined
    }
    const maybeDataUrl = prependPrefix(value, 'data:')
      .replace(/ /g, '+')
      .replace(/\s/g, '')
    return isDataUrl(maybeDataUrl) ? maybeDataUrl : undefined
  }
docs: +'s are replaced with spaces when used in query params, this returns them to +'s, then removes remaining whitespace. https://github.com/badges/shields/pull/1546