move to recommended async test style, minor tweaks

src/cmd/serial.js

@@ -921,12 +921,11 @@ module.exports = class SerialCommand {
 	}
 
 	/**
-	 * This is a wrapper function created so _serialWifiConfig can return the
-	 * true promise state, but the wrapper can still act like it handled any
-	 * failures gracefully as it acted before testing was attempted.
+	 * This is a wrapper function so _serialWifiConfig can return the
+	 * true promise state for testing.
 	 */
 	serialWifiConfig(...args) {
-		return this._serialWifiConfig.apply(this, args)
+		return this._serialWifiConfig(...args)
 			.then(() => {
 				console.log('Done! Your device should now restart.');
 			}, (err) => {
@@ -1221,16 +1220,16 @@ module.exports = class SerialCommand {
 				serialPort.drain();
 
 				// In case device is not in listening mode.
-				startTimeout(5000, 'Serial timed out while initially listening to device, please ensure device is in listening mode with particle usb start-listening');
+				startTimeout(5000, 'Serial timed out while initially listening to device, please ensure device is in listening mode with particle usb start-listening', 'InitialTimeoutError');
 			});
 
 			function serialClosedEarly(){
 				reject('Serial port closed early');
 			}
 
-			function startTimeout(to, message = timeoutError){
+			function startTimeout(to, message = timeoutError, name = 'TimeoutError'){
 				self._serialTimeout = setTimeout(() => {
-					reject(message);
+					reject(VError({name}, message));
 				}, to);
 			}
 

src/cmd/serial.test.js

@@ -62,19 +62,34 @@ describe('Serial Command', () => {
 		});
 	});
 
-	describe('serialWifiConfig', () => {
-		it('can reject with timeout after 5000ms if not getting any serial data', () => {
+	describe('serialWifiConfig', async () => {
+		it('can reject with timeout after 5000ms if not getting any serial data', async () => {
 			clock = sinon.useFakeTimers();
 			const device = { port: 'baltimore' };
 			const mockSerial = new MockSerial();
+
+			mockSerial.write = function write(data) {
+				if (data === 'w') {
+					// This next tick allows _serialWifiConfig to set the timeout before we move the clock foward.
+					process.nextTick(() => {
+						clock.tick(5010);
+					});
+				}
+			};
+
 			serial.serialPort = mockSerial;
-			const wifiPromise = serial._serialWifiConfig(device);
-			// This allows _serialWifiConfig's internal promises to run and try to
-			// connect to the serial device before moving time forward.
-			process.nextTick(() => {
-				clock.tick(5010);
-			});
-			return expect(wifiPromise).to.be.rejected;
+
+
+			let error;
+
+			try {
+				await serial._serialWifiConfig(device);
+			} catch (e) {
+				error = e;
+			}
+
+			expect(error).to.be.an.instanceOf(Error);
+			expect(error).to.have.property('name', 'InitialTimeoutError');
 		});
 	});
 });