persistMirageDb.ts

// https://github.com/miragejs/site/blob/master/src/lib/persist.js
// secret stuff in here.

// increase this number to bust all locally stored mirage
// databases
let currentVersion = 1
let initialData: object

function saveDb(server: any) {
  localStorage.setItem('mirage:db:version', String(currentVersion))
  localStorage.setItem('mirage:db:data', JSON.stringify(server.db.dump()))
}

export function addPersist(server: any) {
  if (typeof window !== 'undefined') {
    initialData = server.db.dump()
    let version = localStorage.getItem('mirage:db:version')
    let dataString = localStorage.getItem('mirage:db:data')

    if (dataString && version === currentVersion.toString()) {
      try {
        resetDb(server, JSON.parse(dataString))
      } catch (e) {
        console.log('Error while addPersist: ', e)
      }
    }

    let originalHandled = server.pretender.handledRequest
    server.pretender.handledRequest = function() {
      // eslint-disable-next-line prefer-rest-params
      originalHandled.call(server.pretender, ...arguments)
      saveDb(server)
    }
  }
}

export function resetDb(server: any, data = initialData) {
  server.db.emptyData()
  server.db.loadData(data)
  saveDb(server)
}