Give transformers access to the full, combined reducer state

src/createPersistoid.js

@@ -10,9 +10,9 @@ export default function createPersistoid(config: PersistConfig): Persistoid {
   const whitelist: ?Array<string> = config.whitelist || null
   const transforms = config.transforms || []
   const throttle = config.throttle || 0
-  const storageKey = `${config.keyPrefix !== undefined
-    ? config.keyPrefix
-    : KEY_PREFIX}${config.key}`
+  const storageKey = `${
+    config.keyPrefix !== undefined ? config.keyPrefix : KEY_PREFIX
+  }${config.key}`
   const storage = config.storage
   const serialize = config.serialize === false ? x => x : defaultSerialize
 
@@ -50,7 +50,7 @@ export default function createPersistoid(config: PersistConfig): Persistoid {
 
     let key = keysToProcess.shift()
     let endState = transforms.reduce((subState, transformer) => {
-      return transformer.in(subState, key)
+      return transformer.in(subState, key, lastState)
     }, lastState[key])
     if (typeof endState !== 'undefined') stagedWrite(key, endState)
   }
@@ -79,7 +79,8 @@ export default function createPersistoid(config: PersistConfig): Persistoid {
   }
 
   function passWhitelistBlacklist(key) {
-    if (whitelist && whitelist.indexOf(key) === -1 && key !== '_persist') return false
+    if (whitelist && whitelist.indexOf(key) === -1 && key !== '_persist')
+      return false
     if (blacklist && blacklist.indexOf(key) !== -1) return false
     return true
   }

src/createTransform.js

@@ -22,9 +22,13 @@ export default function createTransform(
   }
 
   return {
-    in: (state: Object, key: string) =>
-      !whitelistBlacklistCheck(key) && inbound ? inbound(state, key) : state,
-    out: (state: Object, key: string) =>
-      !whitelistBlacklistCheck(key) && outbound ? outbound(state, key) : state,
+    in: (state: Object, key: string, fullState: Object) =>
+      !whitelistBlacklistCheck(key) && inbound
+        ? inbound(state, key, fullState)
+        : state,
+    out: (state: Object, key: string, fullState: Object) =>
+      !whitelistBlacklistCheck(key) && outbound
+        ? outbound(state, key, fullState)
+        : state,
   }
 }

src/getStoredState.js

@@ -8,9 +8,9 @@ export default function getStoredState(
   config: PersistConfig
 ): Promise<Object | void> {
   const transforms = config.transforms || []
-  const storageKey = `${config.keyPrefix !== undefined
-    ? config.keyPrefix
-    : KEY_PREFIX}${config.key}`
+  const storageKey = `${
+    config.keyPrefix !== undefined ? config.keyPrefix : KEY_PREFIX
+  }${config.key}`
   const storage = config.storage
   const debug = config.debug
   const deserialize = config.serialize === false ? x => x : defaultDeserialize
@@ -22,7 +22,7 @@ export default function getStoredState(
         let rawState = deserialize(serialized)
         Object.keys(rawState).forEach(key => {
           state[key] = transforms.reduceRight((subState, transformer) => {
-            return transformer.out(subState, key)
+            return transformer.out(subState, key, rawState)
           }, deserialize(rawState[key]))
         })
         return state

src/types.js

@@ -40,8 +40,8 @@ export type MigrationManifest = {
 }
 
 export type Transform = {
-  in: (Object | string, string) => Object,
-  out: (Object | string, string) => Object,
+  in: (Object | string, string, Object | string) => Object,
+  out: (Object | string, string, Object | string) => Object,
   config?: PersistConfig,
 }