Merge branch 'master' of https://github.com/MetaMask/metamask-extension into cb-254

1 files changed, 23 insertions, 4 deletions

diff --git a/app/scripts/lib/migrator/index.js b/app/scripts/lib/migrator/index.js
index 4fd2cae92..85c2717ea 100644
--- a/app/scripts/lib/migrator/index.js
+++ b/app/scripts/lib/migrator/index.js
@@ -1,6 +1,9 @@
-class Migrator {
+const EventEmitter = require('events')
+
+class Migrator extends EventEmitter {
 
   constructor (opts = {}) {
+    super()
     const migrations = opts.migrations || []
     // sort migrations by version
     this.migrations = migrations.sort((a, b) => a.version - b.version)
@@ -12,13 +15,29 @@ class Migrator {
 
   // run all pending migrations on meta in place
   async migrateData (versionedData = this.generateInitialState()) {
+    // get all migrations that have not yet been run
     const pendingMigrations = this.migrations.filter(migrationIsPending)
 
+    // perform each migration
     for (const index in pendingMigrations) {
       const migration = pendingMigrations[index]
-      versionedData = await migration.migrate(versionedData)
-      if (!versionedData.data) throw new Error('Migrator - migration returned empty data')
-      if (versionedData.version !== undefined && versionedData.meta.version !== migration.version) throw new Error('Migrator - Migration did not update version number correctly')
+      try {
+        // attempt migration and validate
+        const migratedData = await migration.migrate(versionedData)
+        if (!migratedData.data) throw new Error('Migrator - migration returned empty data')
+        if (migratedData.version !== undefined && migratedData.meta.version !== migration.version) throw new Error('Migrator - Migration did not update version number correctly')
+        // accept the migration as good
+        versionedData = migratedData
+      } catch (err) {
+        // rewrite error message to add context without clobbering stack
+        const originalErrorMessage = err.message
+        err.message = `MetaMask Migration Error #${migration.version}: ${originalErrorMessage}`
+        console.warn(err.stack)
+        // emit error instead of throw so as to not break the run (gracefully fail)
+        this.emit('error', err)
+        // stop migrating and use state as is
+        return versionedData
+      }
     }
 
     return versionedData