From 3be9418902b43df2cf681f2ed84f630f9b6d9b7b Mon Sep 17 00:00:00 2001
From: Michael Jackson <mjackson@overstock.com>
Date: Sun, 31 Jul 2016 22:49:37 -0600
Subject: [PATCH] Convert flash to return a promise

---
 lib/flash.js          | 76 +++++++++++++++++++++++--------------------
 lib/tessel/restore.js | 14 ++++----
 2 files changed, 46 insertions(+), 44 deletions(-)

diff --git a/lib/flash.js b/lib/flash.js
index 73e57651..40624c3a 100644
--- a/lib/flash.js
+++ b/lib/flash.js
@@ -25,7 +25,7 @@ function factoryPartition(mac1, mac2) {
   );
 }
 
-function transaction(usbConnection, write, read, status_poll, wren, next) {
+function transaction (usbConnection, write, read, status_poll, wren, next) {
   read = read || 0;
   status_poll = status_poll || false;
   wren = wren || false;
@@ -69,8 +69,8 @@ function eraseChip(usbConnection, next) {
 }
 
 // Poll for the WIP bit in the status register to go low
-function waitTransactionComplete(usbConnection, next) {
-  setTimeout(function onWait() {
+function waitTransactionComplete (usbConnection, next) {
+  setTimeout(function onWait () {
     getStatus(usbConnection, (err, status) => {
       if (err) {
         return next(err);
@@ -138,39 +138,43 @@ function randbyte() {
   return randint(0, 255);
 }
 
-function asyncLog(msg, next) {
-  log.info(msg);
-  next();
+function asyncLog(msg) {
+  return function onAsyncLog(next) {
+    log.info(msg);
+    next();
+  }
 }
 
-module.exports = function flashDevice(usbConnection, ubootBuffer, squashfsBuffer, next) {
-  var uid = [randbyte(), randbyte(), randbyte(), randbyte()];
-  var mac1 = [0x02, 0xa3].concat(uid);
-  var mac2 = [0x02, 0xa4].concat(uid);
-
-  async.waterfall([
-    asyncLog.bind(null, 'Checking the chip id...'),
-    readChipId.bind(null, usbConnection),
-    checkChipId,
-
-    asyncLog.bind(null, 'Erasing the chip...'),
-    setWriteEnabled.bind(null, usbConnection),
-    eraseChip.bind(null, usbConnection),
-    waitTransactionComplete.bind(null, usbConnection),
-
-    asyncLog.bind(null, 'Writing uboot...'),
-    write.bind(null, usbConnection, 0, ubootBuffer),
-    waitTransactionComplete.bind(null, usbConnection),
-
-    asyncLog.bind(null, 'Writing mediatek factory partition...'),
-    write.bind(null, usbConnection, 0x40000, factoryPartition(mac1, mac2)),
-    waitTransactionComplete.bind(null, usbConnection),
-
-    asyncLog.bind(null, 'Writing squashfs...'),
-    write.bind(null, usbConnection, 0x50000, squashfsBuffer),
-    waitTransactionComplete.bind(null, usbConnection),
-    asyncLog.bind(null, 'The update was successful.'),
-    asyncLog.bind(null, 'Please power cycle your Tessel.')
-
-  ], next);
+module.exports = function flashDevice(usbConnection, ubootBuffer, squashfsBuffer) {
+  return new Promise((resolve, reject)=> {
+    var uid = [randbyte(), randbyte(), randbyte(), randbyte()];
+    var mac1 = [0x02, 0xa3].concat(uid);
+    var mac2 = [0x02, 0xa4].concat(uid);
+
+    async.waterfall([
+      asyncLog('Checking the chip id...'),
+      readChipId.bind(null, usbConnection),
+      checkChipId,
+
+      asyncLog('Erasing the chip...'),
+      setWriteEnabled.bind(null, usbConnection),
+      eraseChip.bind(null, usbConnection),
+      waitTransactionComplete.bind(null, usbConnection),
+
+      asyncLog('Writing uboot...'),
+      write.bind(null, usbConnection, 0, ubootBuffer),
+      waitTransactionComplete.bind(null, usbConnection),
+
+      asyncLog('Writing mediatek factory partition...'),
+      write.bind(null, usbConnection, 0x40000, factoryPartition(mac1, mac2)),
+      waitTransactionComplete.bind(null, usbConnection),
+
+      asyncLog('Writing squashfs...'),
+      write.bind(null, usbConnection, 0x50000, squashfsBuffer),
+      waitTransactionComplete.bind(null, usbConnection),
+      asyncLog('The update was successful.'),
+      asyncLog('Please power cycle your Tessel.')
+
+    ], (err) => err ? reject(err) : resolve());
+  })
 };
diff --git a/lib/tessel/restore.js b/lib/tessel/restore.js
index 715c6e64..8aea9954 100644
--- a/lib/tessel/restore.js
+++ b/lib/tessel/restore.js
@@ -10,21 +10,19 @@ var update = require('../update-fetch');
 var log = require('../log');
 var flash = require('../flash');
 
-Tessel.prototype.restore = function restore() {
+Tessel.prototype.restore = function restore () {
   var usbConnection = this.connection;
   return new Promise((resolve, reject) => {
 
     log.info('Proceeding with updating OpenWrt...');
 
     // download images
-    return update.fetchRestore()
+    return update
+      .fetchRestore()
       .then((result) => {
-        flash(usbConnection, result.uboot, result.squashfs, (err) => {
-          if (err) {
-            return reject(err);
-          }
-          resolve();
-        });
+        flash(usbConnection, result.uboot, result.squashfs)
+          .then(resolve)
+          .catch(reject)
       });
   });
 };