migrations - introduce promise-based migrator

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')
@@ -16,27 +17,44 @@ 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
-
-let migrator = new Migrator({
-  migrations,
-  // Data persistence methods
-  loadData: () => dataStore.get(),
-  setData: (newState) => dataStore.put(newState),
-})
+function setupController (initState) {
 
   //
   // MetaMask Controller
@@ -48,10 +66,11 @@ const controller = new MetamaskController({
     unlockAccountMessage: triggerUi,
     showUnapprovedTx: triggerUi,
     // initial state
-  initState: migrator.getData(),
+    initState,
   })
+
   // setup state persistence
-controller.store.subscribe((newState) => migrator.saveData(newState))
+  controller.store.subscribe((newState) => diskStore)
 
   //
   // connect to other contexts
@@ -113,20 +132,9 @@ function setupControllerConnection (stream) {
   // User Interface setup
   //
 
-// popup trigger
-function triggerUi () {
-  if (!popupIsOpen) notification.show()
-}
-
-// On first install, open a window to MetaMask website to how-it-works.
-extension.runtime.onInstalled.addListener(function (details) {
-  if ((details.reason === 'install') && (!METAMASK_DEBUG)) {
-    extension.tabs.create({url: 'https://metamask.io/#how-it-works'})
-  }
-})
+  controller.txManager.on('updateBadge', updateBadge)
 
   // plugin badge text
-controller.txManager.on('updateBadge', updateBadge)
   function updateBadge () {
     var label = ''
     var unapprovedTxCount = controller.txManager.unapprovedTxCount
@@ -139,3 +147,23 @@ function updateBadge () {
     extension.browserAction.setBadgeText({ text: label })
     extension.browserAction.setBadgeBackgroundColor({ color: '#506F8B' })
   }
+
+  return Promise.resolve()
+
+}
+
+//
+// Etc...
+//
+
+// popup trigger
+function triggerUi () {
+  if (!popupIsOpen) notification.show()
+}
+
+// On first install, open a window to MetaMask website to how-it-works.
+extension.runtime.onInstalled.addListener(function (details) {
+  if ((details.reason === 'install') && (!METAMASK_DEBUG)) {
+    extension.tabs.create({url: 'https://metamask.io/#how-it-works'})
+  }
+})

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

app/scripts/migrations/002.js

@@ -1,13 +1,16 @@
-module.exports = {
-  version: 2,
+const version = 2
 
-  migrate: function (data) {
+module.exports = {
+  version,
+
+  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)
   },
 }

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)
   },
 }

app/scripts/migrations/004.js

@@ -1,22 +1,25 @@
-module.exports = {
-  version: 4,
+const version = 4
 
-  migrate: function (data) {
+module.exports = {
+  version,  
+
+  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)
   },
 }

package.json

@@ -37,6 +37,7 @@
   },
   "dependencies": {
     "async": "^1.5.2",
+    "async-q": "^0.3.1",
     "bip39": "^2.2.0",
     "browser-passworder": "^2.0.3",
     "browserify-derequire": "^0.9.4",

test/unit/migrations-test.js

@@ -1,34 +1,34 @@
-var assert = require('assert')
-var path = require('path')
+const assert = require('assert')
+const path = require('path')
 
-var wallet1 = require(path.join('..', 'lib', 'migrations', '001.json'))
+const wallet1 = require(path.join('..', 'lib', 'migrations', '001.json'))
 
-var migration2 = require(path.join('..', '..', 'app', 'scripts', 'migrations', '002'))
-var migration3 = require(path.join('..', '..', 'app', 'scripts', 'migrations', '003'))
-var migration4 = require(path.join('..', '..', 'app', 'scripts', 'migrations', '004'))
+const migration2 = require(path.join('..', '..', 'app', 'scripts', 'migrations', '002'))
+const migration3 = require(path.join('..', '..', 'app', 'scripts', 'migrations', '003'))
+const migration4 = require(path.join('..', '..', 'app', 'scripts', 'migrations', '004'))
+
+const oldTestRpc = 'https://rawtestrpc.metamask.io/'
+const newTestRpc = 'https://testrpc.metamask.io/'
 
 describe('wallet1 is migrated successfully', function() {
-
-  it('should convert providers', function(done) {
+  it('should convert providers', function() {
 
     wallet1.data.config.provider = { type: 'etherscan', rpcTarget: null }
 
-    var firstResult = migration2.migrate(wallet1.data)
-    assert.equal(firstResult.config.provider.type, 'rpc', 'provider should be rpc')
-    assert.equal(firstResult.config.provider.rpcTarget, 'https://rpc.metamask.io/', 'main provider should be our rpc')
+    return migration2.migrate(wallet1)
+    .then((firstResult) => {
+      assert.equal(firstResult.data.config.provider.type, 'rpc', 'provider should be rpc')
+      assert.equal(firstResult.data.config.provider.rpcTarget, 'https://rpc.metamask.io/', 'main provider should be our rpc')
+      firstResult.data.config.provider.rpcTarget = oldTestRpc
+      return migration3.migrate(firstResult)
+    }).then((secondResult) => {
+      assert.equal(secondResult.data.config.provider.rpcTarget, newTestRpc)
+      return migration4.migrate(secondResult)
+    }).then((thirdResult) => {
+      assert.equal(thirdResult.data.config.provider.rpcTarget, null)
+      assert.equal(thirdResult.data.config.provider.type, 'testnet')
+    })
     
-    var oldTestRpc = 'https://rawtestrpc.metamask.io/'
-    var newTestRpc = 'https://testrpc.metamask.io/'
-    firstResult.config.provider.rpcTarget = oldTestRpc
-
-    var secondResult = migration3.migrate(firstResult)
-    assert.equal(secondResult.config.provider.rpcTarget, newTestRpc)
-
-    var thirdResult = migration4.migrate(secondResult)
-    assert.equal(secondResult.config.provider.rpcTarget, null)
-    assert.equal(secondResult.config.provider.type, 'testnet')
-
-    done()
   })
 })