[WIP] Enable syncing of vault/preferences between multiple browsers

app/scripts/background.js

@@ -4,6 +4,7 @@ const pump = require('pump')
 const log = require('loglevel')
 const extension = require('extensionizer')
 const LocalStorageStore = require('obs-store/lib/localStorage')
+const ExtensionStore = require('./lib/extension-store')
 const storeTransform = require('obs-store/lib/transform')
 const asStream = require('obs-store/lib/asStream')
 const ExtensionPlatform = require('./platforms/extension')
@@ -28,6 +29,7 @@ let popupIsOpen = false
 
 // state persistence
 const diskStore = new LocalStorageStore({ storageKey: STORAGE_KEY })
+const extensionStore = new ExtensionStore()
 
 // initialization flow
 initialize().catch(log.error)
@@ -47,6 +49,13 @@ async function loadStateFromPersistence () {
   const migrator = new Migrator({ migrations })
   // read from disk
   let versionedData = diskStore.getState() || migrator.generateInitialState(firstTimeState)
+  // fetch from extension store and merge in data
+
+  if (extensionStore.isSupported && extensionStore.isEnabled) {
+    const extensionData = await extensionStore.fetch() // TODO: handle possible exceptions (https://developer.chrome.com/apps/runtime#property-lastError)
+    versionedData = { ...versionedData, ...extensionData }
+  }
+
   // migrate data
   versionedData = await migrator.migrateData(versionedData)
   // write to disk
@@ -76,6 +85,7 @@ function setupController (initState) {
   pump(
     asStream(controller.store),
     storeTransform(versionifyData),
+    storeTransform(syncDataWithExtension),
     asStream(diskStore)
   )
 
@@ -85,6 +95,13 @@ function setupController (initState) {
     return versionedData
   }
 
+  function syncDataWithExtension(state) {
+    if (extensionStore.isSupported && extensionStore.isEnabled) {
+      extensionStore.sync(state) // TODO: handle possible exceptions (https://developer.chrome.com/apps/runtime#property-lastError)
+    }
+    return state
+  }
+
   //
   // connect to other contexts
   //

app/scripts/lib/extension-store.js

@@ -0,0 +1,39 @@
+const extension = require('extensionizer')
+
+const KEYS_TO_SYNC = ['KeyringController', 'PreferencesController']
+const FIREFOX_SYNC_DISABLED_MESSAGE = 'Please set webextensions.storage.sync.enabled to true in about:config'
+
+const handleDisabledSyncAndResolve = (resolve, toResolve) => {
+  // Firefox 52 has sync available on extension.storage, but it is disabled by default
+  const lastError = extension.runtime.lastError
+  if (lastError && lastError.message.includes(FIREFOX_SYNC_DISABLED_MESSAGE)) {
+    resolve({})
+  } else {
+    resolve(toResolve)
+  }
+}
+
+module.exports = class ExtensionStore {
+  constructor() {
+    this.isSupported = !!(extension.storage.sync)
+    this.isEnabled = true // TODO: get value from user settings
+  }
+  async fetch() {
+    return new Promise((resolve) => {
+      extension.storage.sync.get(KEYS_TO_SYNC, (data) => {
+        handleDisabledSyncAndResolve(resolve, data)
+      })
+    })
+  }
+  async sync(state) {
+    const dataToSync = KEYS_TO_SYNC.reduce((result, key) => {
+      result[key] = state.data[key]
+      return result
+    }, {})
+    return new Promise((resolve) => {
+      extension.storage.sync.set(dataToSync, () => {
+        handleDisabledSyncAndResolve(resolve)
+      })
+    })
+  }
+}

test/unit/extension-store-test.js

@@ -0,0 +1,29 @@
+const assert = require('assert')
+
+const ExtensionStore = require('../../app/scripts/lib/extension-store')
+
+describe('Extension Store', function () {
+  let extensionStore
+
+  beforeEach(function () {
+    extensionStore = new ExtensionStore()
+  })
+
+  describe('#fetch', function () {
+    it('should return a promise', function () {
+
+    })
+    it('after promise resolution, should have loaded the proper data from the extension', function () {
+
+    })
+  })
+
+  describe('#sync', function () {
+    it('should return a promise', function () {
+
+    })
+    it('after promise resolution, should have synced the proper data from the extension', function () {
+
+    })
+  })
+})