Merge pull request #1417 from MetaMask/fixMigrator2

Fix and simplify migrator with es7

app/scripts/lib/migrator/index.js

@@ -1,42 +1,35 @@
-const asyncQ = require('async-q')
-
 class Migrator {
 
   constructor (opts = {}) {
     const migrations = opts.migrations || []
+    // sort migrations by version
     this.migrations = migrations.sort((a, b) => a.version - b.version)
+    // grab migration with highest version
     const 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 (versionedData = this.generateInitialState()) {
-    const remaining = this.migrations.filter(migrationIsPending)
+  async migrateData (versionedData = this.generateInitialState()) {
+    const pendingMigrations = this.migrations.filter(migrationIsPending)
 
-    return (
-      asyncQ.eachSeries(remaining, (migration) => this.runMigration(versionedData, migration))
-      .then(() => versionedData)
-    )
+    for (let index in pendingMigrations) {
+      let 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')
+    }
 
-    // migration is "pending" if hit has a higher
+    return versionedData
+
+    // migration is "pending" if it has a higher
     // version number than currentVersion
     function migrationIsPending (migration) {
       return migration.version > versionedData.meta.version
     }
   }
 
-  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: {

circle.yml

@@ -1,6 +1,6 @@
 machine:
   node:
-    version: 6.0.0
+    version: 7.6.0
 dependencies:
   pre:
     - "npm i -g testem"

test/unit/migrator-test.js

@@ -0,0 +1,41 @@
+const assert = require('assert')
+const clone = require('clone')
+const Migrator = require('../../app/scripts/lib/migrator/')
+const migrations = [
+  {
+    version: 1,
+    migrate: (data) => {
+      // clone the data just like we do in migrations
+      const clonedData = clone(data)
+      clonedData.meta.version = 1
+      return Promise.resolve(clonedData)
+    },
+  },
+  {
+    version: 2,
+    migrate: (data) => {
+      const clonedData = clone(data)
+      clonedData.meta.version = 2
+      return Promise.resolve(clonedData)
+    },
+  },
+  {
+    version: 3,
+    migrate: (data) => {
+      const clonedData = clone(data)
+      clonedData.meta.version = 3
+      return Promise.resolve(clonedData)
+    },
+  },
+]
+const versionedData = {meta: {version: 0}, data:{hello:'world'}}
+describe('Migrator', () => {
+  const migrator = new Migrator({ migrations })
+  it('migratedData version should be version 3', (done) => {
+    migrator.migrateData(versionedData)
+    .then((migratedData) => {
+      assert.equal(migratedData.meta.version, migrations[2].version)
+      done()
+    }).catch(done)
+  })
+})