migrations - introduce promise-based migrator

1 files changed, 120 insertions, 92 deletions

diff --git a/app/scripts/background.js b/app/scripts/background.js
index 8aa886594..697417fd2 100644
--- a/app/scripts/background.js
+++ b/app/scripts/background.js
@@ -1,7 +1,8 @@
 const urlUtil = require('url')
 const Dnode = require('dnode')
 const eos = require('end-of-stream')
-const Migrator = require('pojo-migrator')
+const asyncQ = require('async-q')
+const Migrator = require('./lib/migrator/')
 const migrations = require('./lib/migrations')
 const LocalStorageStore = require('./lib/observable/local-storage')
 const PortStream = require('./lib/port-stream.js')
@@ -16,101 +17,143 @@ const STORAGE_KEY = 'metamask-config'
 const METAMASK_DEBUG = 'GULP_METAMASK_DEBUG'
 let popupIsOpen = false
 
+// state persistence
+const diskStore = new LocalStorageStore({ storageKey: STORAGE_KEY })
+
+// initialization flow
+asyncQ.waterfall([
+  () => loadStateFromPersistence(),
+  (initState) => setupController(initState),
+])
+.then(() => console.log('MetaMask initialization complete.'))
+.catch((err) => { console.error(err) })
 
 //
 // State and Persistence
 //
 
-// state persistence
-
-let dataStore = new LocalStorageStore({ storageKey: STORAGE_KEY })
-// initial state for first time users
-if (!dataStore.get()) {
-  dataStore.put({ meta: { version: 0 }, data: firstTimeState })
+function loadStateFromPersistence() {
+  // migrations
+  let migrator = new Migrator({ migrations })
+  let initialState = {
+    meta: { version: migrator.defaultVersion },
+    data: firstTimeState,
+  }
+  return asyncQ.waterfall([
+    // read from disk
+    () => Promise.resolve(diskStore.get() || initialState),
+    // migrate data
+    (versionedData) => migrator.migrateData(versionedData),
+    // write to disk
+    (versionedData) => {
+      diskStore.put(versionedData)
+      return Promise.resolve(versionedData)
+    },
+    // resolve to just data
+    (versionedData) => Promise.resolve(versionedData.data),
+  ])
 }
 
-// migrations
+function setupController (initState) {
 
-let migrator = new Migrator({
-  migrations,
-  // Data persistence methods
-  loadData: () => dataStore.get(),
-  setData: (newState) => dataStore.put(newState),
-})
+  //
+  // MetaMask Controller
+  //
 
-//
-// MetaMask Controller
-//
+  const controller = new MetamaskController({
+    // User confirmation callbacks:
+    showUnconfirmedMessage: triggerUi,
+    unlockAccountMessage: triggerUi,
+    showUnapprovedTx: triggerUi,
+    // initial state
+    initState,
+  })
 
-const controller = new MetamaskController({
-  // User confirmation callbacks:
-  showUnconfirmedMessage: triggerUi,
-  unlockAccountMessage: triggerUi,
-  showUnapprovedTx: triggerUi,
-  // initial state
-  initState: migrator.getData(),
-})
-// setup state persistence
-controller.store.subscribe((newState) => migrator.saveData(newState))
+  // setup state persistence
+  controller.store.subscribe((newState) => diskStore)
+
+  //
+  // connect to other contexts
+  //
+
+  extension.runtime.onConnect.addListener(connectRemote)
+  function connectRemote (remotePort) {
+    var isMetaMaskInternalProcess = remotePort.name === 'popup' || remotePort.name === 'notification'
+    var portStream = new PortStream(remotePort)
+    if (isMetaMaskInternalProcess) {
+      // communication with popup
+      popupIsOpen = remotePort.name === 'popup'
+      setupTrustedCommunication(portStream, 'MetaMask', remotePort.name)
+    } else {
+      // communication with page
+      var originDomain = urlUtil.parse(remotePort.sender.url).hostname
+      setupUntrustedCommunication(portStream, originDomain)
+    }
+  }
 
-//
-// connect to other contexts
-//
+  function setupUntrustedCommunication (connectionStream, originDomain) {
+    // setup multiplexing
+    var mx = setupMultiplex(connectionStream)
+    // connect features
+    controller.setupProviderConnection(mx.createStream('provider'), originDomain)
+    controller.setupPublicConfig(mx.createStream('publicConfig'))
+  }
 
-extension.runtime.onConnect.addListener(connectRemote)
-function connectRemote (remotePort) {
-  var isMetaMaskInternalProcess = remotePort.name === 'popup' || remotePort.name === 'notification'
-  var portStream = new PortStream(remotePort)
-  if (isMetaMaskInternalProcess) {
-    // communication with popup
-    popupIsOpen = remotePort.name === 'popup'
-    setupTrustedCommunication(portStream, 'MetaMask', remotePort.name)
-  } else {
-    // communication with page
-    var originDomain = urlUtil.parse(remotePort.sender.url).hostname
-    setupUntrustedCommunication(portStream, originDomain)
+  function setupTrustedCommunication (connectionStream, originDomain) {
+    // setup multiplexing
+    var mx = setupMultiplex(connectionStream)
+    // connect features
+    setupControllerConnection(mx.createStream('controller'))
+    controller.setupProviderConnection(mx.createStream('provider'), originDomain)
   }
-}
 
-function setupUntrustedCommunication (connectionStream, originDomain) {
-  // setup multiplexing
-  var mx = setupMultiplex(connectionStream)
-  // connect features
-  controller.setupProviderConnection(mx.createStream('provider'), originDomain)
-  controller.setupPublicConfig(mx.createStream('publicConfig'))
-}
+  //
+  // remote features
+  //
+
+  function setupControllerConnection (stream) {
+    controller.stream = stream
+    var api = controller.getApi()
+    var dnode = Dnode(api)
+    stream.pipe(dnode).pipe(stream)
+    dnode.on('remote', (remote) => {
+      // push updates to popup
+      var sendUpdate = remote.sendUpdate.bind(remote)
+      controller.on('update', sendUpdate)
+      // teardown on disconnect
+      eos(stream, () => {
+        controller.removeListener('update', sendUpdate)
+        popupIsOpen = false
+      })
+    })
+  }
 
-function setupTrustedCommunication (connectionStream, originDomain) {
-  // setup multiplexing
-  var mx = setupMultiplex(connectionStream)
-  // connect features
-  setupControllerConnection(mx.createStream('controller'))
-  controller.setupProviderConnection(mx.createStream('provider'), originDomain)
-}
+  //
+  // User Interface setup
+  //
+
+  controller.txManager.on('updateBadge', updateBadge)
+
+  // plugin badge text
+  function updateBadge () {
+    var label = ''
+    var unapprovedTxCount = controller.txManager.unapprovedTxCount
+    var unconfMsgs = messageManager.unconfirmedMsgs()
+    var unconfMsgLen = Object.keys(unconfMsgs).length
+    var count = unapprovedTxCount + unconfMsgLen
+    if (count) {
+      label = String(count)
+    }
+    extension.browserAction.setBadgeText({ text: label })
+    extension.browserAction.setBadgeBackgroundColor({ color: '#506F8B' })
+  }
 
-//
-// remote features
-//
+  return Promise.resolve()
 
-function setupControllerConnection (stream) {
-  controller.stream = stream
-  var api = controller.getApi()
-  var dnode = Dnode(api)
-  stream.pipe(dnode).pipe(stream)
-  dnode.on('remote', (remote) => {
-    // push updates to popup
-    var sendUpdate = remote.sendUpdate.bind(remote)
-    controller.on('update', sendUpdate)
-    // teardown on disconnect
-    eos(stream, () => {
-      controller.removeListener('update', sendUpdate)
-      popupIsOpen = false
-    })
-  })
 }
 
 //
-// User Interface setup
+// Etc...
 //
 
 // popup trigger
@@ -123,19 +166,4 @@ extension.runtime.onInstalled.addListener(function (details) {
   if ((details.reason === 'install') && (!METAMASK_DEBUG)) {
     extension.tabs.create({url: 'https://metamask.io/#how-it-works'})
   }
-})
-
-// plugin badge text
-controller.txManager.on('updateBadge', updateBadge)
-function updateBadge () {
-  var label = ''
-  var unapprovedTxCount = controller.txManager.unapprovedTxCount
-  var unconfMsgs = messageManager.unconfirmedMsgs()
-  var unconfMsgLen = Object.keys(unconfMsgs).length
-  var count = unapprovedTxCount + unconfMsgLen
-  if (count) {
-    label = String(count)
-  }
-  extension.browserAction.setBadgeText({ text: label })
-  extension.browserAction.setBadgeBackgroundColor({ color: '#506F8B' })
-}
+})
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