migrations - introduce promise-based migrator

5 files changed, 179 insertions, 112 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' })
-}
+})
\ No newline at end of file
diff --git a/app/scripts/lib/migrator/index.js b/app/scripts/lib/migrator/index.js
new file mode 100644
index 000000000..02d8c2335
--- /dev/null
+++ b/app/scripts/lib/migrator/index.js
@@ -0,0 +1,31 @@
+const asyncQ = require('async-q')
+
+class Migrator {
+
+  constructor (opts = {}) {
+    let migrations = opts.migrations || []
+    this.migrations = migrations.sort((a, b) => a.version - b.version)
+    let lastMigration = this.migrations.slice(-1)[0]
+    // use specified defaultVersion or highest migration version
+    this.defaultVersion = opts.defaultVersion || lastMigration && lastMigration.version || 0
+  }
+
+  // run all pending migrations on meta in place
+  migrateData (meta = { version: this.defaultVersion }) {
+    let remaining = this.migrations.filter(migrationIsPending)
+    
+    return (
+      asyncQ.eachSeries(remaining, (migration) => migration.migrate(meta))
+      .then(() => meta)
+    )
+
+    // migration is "pending" if hit has a higher
+    // version number than currentVersion
+    function migrationIsPending(migration) {
+      return migration.version > meta.version
+    }
+  }
+
+}
+
+module.exports = Migrator
diff --git a/app/scripts/migrations/002.js b/app/scripts/migrations/002.js
index 0b654f825..97f427d3a 100644
--- a/app/scripts/migrations/002.js
+++ b/app/scripts/migrations/002.js
@@ -1,13 +1,16 @@
+const version = 2
+
 module.exports = {
-  version: 2,
+  version,
 
-  migrate: function (data) {
+  migrate: function (meta) {
+    meta.version = version
     try {
-      if (data.config.provider.type === 'etherscan') {
-        data.config.provider.type = 'rpc'
-        data.config.provider.rpcTarget = 'https://rpc.metamask.io/'
+      if (meta.data.config.provider.type === 'etherscan') {
+        meta.data.config.provider.type = 'rpc'
+        meta.data.config.provider.rpcTarget = 'https://rpc.metamask.io/'
       }
     } catch (e) {}
-    return data
+    return Promise.resolve(meta)
   },
 }
diff --git a/app/scripts/migrations/003.js b/app/scripts/migrations/003.js
index 617c55c09..b25e26e01 100644
--- a/app/scripts/migrations/003.js
+++ b/app/scripts/migrations/003.js
@@ -1,15 +1,17 @@
-var oldTestRpc = 'https://rawtestrpc.metamask.io/'
-var newTestRpc = 'https://testrpc.metamask.io/'
+const version = 3
+const oldTestRpc = 'https://rawtestrpc.metamask.io/'
+const newTestRpc = 'https://testrpc.metamask.io/'
 
 module.exports = {
-  version: 3,
+  version,
 
-  migrate: function (data) {
+  migrate: function (meta) {
+    meta.version = version
     try {
-      if (data.config.provider.rpcTarget === oldTestRpc) {
-        data.config.provider.rpcTarget = newTestRpc
+      if (meta.data.config.provider.rpcTarget === oldTestRpc) {
+        meta.data.config.provider.rpcTarget = newTestRpc
       }
     } catch (e) {}
-    return data
+    return Promise.resolve(meta)
   },
 }
diff --git a/app/scripts/migrations/004.js b/app/scripts/migrations/004.js
index 1329a1eed..e72eef2b7 100644
--- a/app/scripts/migrations/004.js
+++ b/app/scripts/migrations/004.js
@@ -1,22 +1,25 @@
+const version = 4
+
 module.exports = {
-  version: 4,
+  version,  
 
-  migrate: function (data) {
+  migrate: function (meta) {
+    meta.version = version
     try {
-      if (data.config.provider.type !== 'rpc') return data
-      switch (data.config.provider.rpcTarget) {
+      if (meta.data.config.provider.type !== 'rpc') return Promise.resolve(meta)
+      switch (meta.data.config.provider.rpcTarget) {
         case 'https://testrpc.metamask.io/':
-          data.config.provider = {
+          meta.data.config.provider = {
             type: 'testnet',
           }
           break
         case 'https://rpc.metamask.io/':
-          data.config.provider = {
+          meta.data.config.provider = {
             type: 'mainnet',
           }
           break
       }
     } catch (_) {}
-    return data
+    return Promise.resolve(meta)
   },
 }