initial commit

- just the source code itself

localStorageAdaptor.js

@@ -0,0 +1,23 @@
+export function clear () {
+  return callWithPromise(window.localStorage.clear)
+}
+
+export function getItem (key) {
+  return callWithPromise(window.localStorage.getItem, key)
+}
+
+export function removeItem (key) {
+  return callWithPromise(window.localStorage.removeItem, key)
+}
+
+export function setItem (key, value) {
+  return callWithPromise(window.localStorage.setItem, key, value)
+}
+
+function callWithPromise (func, ...args) {
+  try {
+    return Promise.resolve(func(...args))
+  } catch (err) {
+    return Promise.reject(err)
+  }
+}

persist.js

@@ -0,0 +1,43 @@
+import { onSnapshot, applySnapshot } from 'mobx-state-tree'
+
+import * as LocalStorage from './localStorageAdaptor.js'
+
+export const persist = (name, store, options = {}) => {
+  let {storage, whitelist, blacklist, jsonify} = options
+
+  if (typeof window.localStorage !== 'undefined' && window.localStorage === storage) {
+    storage = LocalStorage
+  }
+  const whitelistDict = arrToDict(whitelist)
+  const blacklistDict = arrToDict(blacklist)
+  if (!jsonify) { jsonify = true } // default to true like mobx-persist
+
+  onSnapshot(store, (_snapshot) => {
+    const snapshot = { ..._snapshot }
+    Object.keys(snapshot).forEach((key) => {
+      if (whitelist && !whitelistDict[key]) {
+        delete snapshot[key]
+      }
+      if (blacklist && blacklistDict[key]) {
+        delete snapshot[key]
+      }
+    })
+
+    const data = !jsonify ? snapshot : JSON.stringify(snapshot)
+    storage.setItem(name, data)
+  })
+
+  return storage.getItem(name)
+    .then((data) => {
+      const snapshot = !jsonify ? data : JSON.parse(data)
+      applySnapshot(store, snapshot)
+    })
+}
+
+function arrToDict (arr) {
+  if (!arr) { return {} }
+  return arr.reduce((dict, elem) => {
+    dict[elem] = true
+    return dict
+  }, {})
+}