migrations - fix migration #9 and add safety checks to migrator

app/scripts/lib/migrator/index.js

@@ -15,7 +15,7 @@ class Migrator {
     let remaining = this.migrations.filter(migrationIsPending)
     
     return (
-      asyncQ.eachSeries(remaining, (migration) => migration.migrate(versionedData))
+      asyncQ.eachSeries(remaining, (migration) => this.runMigration(versionedData, migration))
       .then(() => versionedData)
     )
 
@@ -26,6 +26,17 @@ class Migrator {
     }
   }
 
+  runMigration(versionedData, migration) {
+    return (
+      migration.migrate(versionedData)
+      .then((versionedData) => {
+        if (!versionedData.data) return Promise.reject(new Error('Migrator - Migration returned empty data'))
+        if (migration.version !== undefined && versionedData.meta.version !== migration.version) return Promise.reject(new Error('Migrator - Migration did not update version number correctly'))
+        return Promise.resolve(versionedData)
+      })
+    )
+  }
+
   generateInitialState (initState) {
     return {
       meta: {

app/scripts/migrations/009.js

@@ -6,7 +6,7 @@ This migration breaks out the CurrencyController substate
 
 */
 
-const merge = require('deep-merge')
+const merge = require('deep-extend')
 
 module.exports = {
   version,  
@@ -25,7 +25,7 @@ module.exports = {
 }
 
 function transformState (state) {
-  const newState = merge(state, {
+  const newState = merge({}, state, {
     CurrencyController: {
       currentCurrency: state.currentFiat || 'USD',
       conversionRate: state.conversionRate,

package.json

@@ -45,7 +45,7 @@
     "clone": "^1.0.2",
     "copy-to-clipboard": "^2.0.0",
     "debounce": "^1.0.0",
-    "deep-merge": "^1.0.0",
+    "deep-extend": "^0.4.1",
     "denodeify": "^1.2.1",
     "disc": "^1.3.2",
     "dnode": "^1.2.2",