validate-response-body.js

const Ajv = require('ajv')
const ajv = Ajv()

module.exports = function (schema) {
  const validate = ajv.compile(schema)
  return (req, res, next) => {
    const isValid = validate(res.body)
    if (!isValid) {
      console.log('invalid list response', validate.errors)
      res.status(500)
    } else {
      res.status(res.statusCode || 200).json(res.body)
    }
  }
}