add customizing serializer/deserializer config

Author: scott1028

src/createPersistoid.js

@@ -16,7 +16,10 @@ export default function createPersistoid(config: PersistConfig): Persistoid {
     config.keyPrefix !== undefined ? config.keyPrefix : KEY_PREFIX
   }${config.key}`
   const storage = config.storage
-  const serialize = config.serialize === false ? x => x : defaultSerialize
+  let serialize = config.serialize === false ? x => x : defaultSerialize
+  if (typeof config.serialize === 'function') {
+    serialize = config.serialize
+  }
   const writeFailHandler = config.writeFailHandler || null
 
   // initialize stateful values

src/getStoredState.js

@@ -13,7 +13,10 @@ export default function getStoredState(
   }${config.key}`
   const storage = config.storage
   const debug = config.debug
-  const deserialize = config.serialize === false ? x => x : defaultDeserialize
+  let deserialize = config.serialize === false ? x => x : defaultDeserialize
+  if (typeof config.deserialize === 'function') {
+    deserialize = config.deserialize
+  }
   return storage.getItem(storageKey).then(serialized => {
     if (!serialized) return undefined
     else {

src/types.js

@@ -23,7 +23,8 @@ export type PersistConfig = {
   stateReconciler?: false | Function,
   getStoredState?: PersistConfig => Promise<PersistedState>, // used for migrations
   debug?: boolean,
-  serialize?: boolean,
+  serialize?: boolean | Function,
+  deserialize?: Function | null,
   timeout?: number,
   writeFailHandler?: Function,
 }