From e6501112210d8fb84f075a3df8d6db4ca4d093ef Mon Sep 17 00:00:00 2001
From: Erin Peach <erin@code.org>
Date: Wed, 11 Dec 2019 17:04:17 -0800
Subject: [PATCH 1/3] Allow serialport to be overridden

---
 client/MBFirmataClient.js | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/client/MBFirmataClient.js b/client/MBFirmataClient.js
index 8c20668..f038d02 100644
--- a/client/MBFirmataClient.js
+++ b/client/MBFirmataClient.js
@@ -32,11 +32,12 @@ SOFTWARE.
  * Clients can listen for DAL events, digital pin changes, or analog channel updates.
  */
 
-const serialport = require('serialport');
+let serialport;
 const {TextEncoder, TextDecoder} = require('util');
 
 class MicrobitFirmataClient {
-	constructor() {
+	constructor(port) {
+    serialport = port ? port : require('serialport');
 		this.addConstants();
 		this.myPort = null;
 		this.inbuf = new Uint8Array(1000);

From f8dffd61aa5d3fe918559727e41b47f1572c68f8 Mon Sep 17 00:00:00 2001
From: Erin Peach <erin@code.org>
Date: Wed, 11 Dec 2019 17:07:24 -0800
Subject: [PATCH 2/3] Allow the TextEncoder, TextDecoder to work in node and
 browser

---
 client/MBFirmataClient.js | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/client/MBFirmataClient.js b/client/MBFirmataClient.js
index f038d02..7ab9a30 100644
--- a/client/MBFirmataClient.js
+++ b/client/MBFirmataClient.js
@@ -33,7 +33,16 @@ SOFTWARE.
  */
 
 let serialport;
-const {TextEncoder, TextDecoder} = require('util');
+let TextEncoder, TextDecoder;
+
+// If running outside of the browser, create the TextEncoder/TextDecoder
+if (typeof window === 'undefined' || !window.TextEncoder) {
+  TextEncoder = require('util').TextEncoder;
+  TextDecoder = require('util').TextDecoder;
+} else {
+  TextEncoder = window.TextEncoder;
+  TextDecoder = window.TextDecoder;
+}
 
 class MicrobitFirmataClient {
 	constructor(port) {

From 119d2e149620c76da6af3033222cbd9e600baba5 Mon Sep 17 00:00:00 2001
From: Erin Peach <erin@code.org>
Date: Wed, 11 Dec 2019 17:14:51 -0800
Subject: [PATCH 3/3] Connecting to port return promises

---
 client/MBFirmataClient.js | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/client/MBFirmataClient.js b/client/MBFirmataClient.js
index 7ab9a30..44faef9 100644
--- a/client/MBFirmataClient.js
+++ b/client/MBFirmataClient.js
@@ -119,10 +119,13 @@ class MicrobitFirmataClient {
 
 	// Connecting/Disconnecting
 
+  /**
+   * @returns {Promise} when port has been opened or if no port found
+   */
 	connect() {
 		// Search serial port list for a connected micro:bit and, if found, open that port.
 
-		serialport.list()
+		return serialport.list()
 		.then((ports) => {
 			for (var i = 0; i < ports.length; i++) {
 				var p = ports[i];
@@ -137,13 +140,17 @@ class MicrobitFirmataClient {
 				// Attempt to open the serial port on the given port name.
 				// If this fails it will fail with an UnhandledPromiseRejectionWarning.
 				console.log("Opening", portName);
-				this.setSerialPort(new serialport(portName, { baudRate: 57600 }));
+				return this.setSerialPort(new serialport(portName, { baudRate: 57600 }));
 			} else {
 				console.log("No micro:bit found; is your board plugged in?");
+				return null;
 			}
 		});
 	}
 
+  /**
+   * @returns {Promise} when board version is set
+   */
 	setSerialPort(port) {
 		// Use the given port. Assume the port has been opened by the caller.
 
@@ -161,7 +168,7 @@ class MicrobitFirmataClient {
 
 		// get the board serial number (used to determine board version)
 		this.boardVersion = '';
-		serialport.list()
+		return serialport.list()
 		.then((ports) => {
 			for (var i = 0; i < ports.length; i++) {
 				var p = ports[i];