guardia-messenger/node_modules/json-schema-deref-sync/lib/loaders/file.js

const fs = require('fs')
const path = require('path')
const { getRefFilePath } = require('../utils')

var cwd = process.cwd()

/**
 * Resolves a file link of a json schema to the actual value it references
 * @param refValue the value. String. Ex. `/some/path/schema.json#/definitions/foo`
 * @param options
 *              baseFolder - the base folder to get relative path files from. Default is `process.cwd()`
 * @returns {*}
 * @private
 */
module.exports = function (refValue, options) {
  let refPath = refValue
  const baseFolder = options.baseFolder ? path.resolve(cwd, options.baseFolder) : cwd

  if (refPath.indexOf('file:') === 0) {
    refPath = refPath.substring(5)
  } else {
    refPath = path.resolve(baseFolder, refPath)
  }

  const filePath = getRefFilePath(refPath)

  let newValue
  try {
    var data = fs.readFileSync(filePath)
    newValue = JSON.parse(data)
  } catch (e) {}

  return newValue
};