Correct and simplify channel validation. Closes tesselgh-10

examples/relay.js

@@ -10,7 +10,7 @@ values to the console upon latching.
 var tessel = require('tessel');
 var relaylib = require('../'); // Replace '../' with 'relay-mono' in your own code
 
-var relay = relaylib.use(tessel.port['A']);  
+var relay = relaylib.use(tessel.port['A']);
 
 // Wait for the module to connect
 relay.on('ready', function relayReady () {

index.js

@@ -10,10 +10,16 @@
 var util = require('util');
 var events = require('events');
 
+var invalidChannel = 'Invalid relay channel. Expected 1 or 2.';
+
+function isInvalidChannel(channel) {
+	return channel !== 1 && channel !== 2;
+}
+
 function Relay(hardware, callback) {
 	// Save the port
 	this.hardware = hardware;
-	
+
 	// Set the gpios as output
 	this.hardware.digital[0].output(false);
 	this.hardware.digital[1].output(false);
@@ -32,9 +38,9 @@ function Relay(hardware, callback) {
 util.inherits(Relay, events.EventEmitter);
 
 Relay.prototype._setValue = function(channel, value, callback) {
-	var err;
-	if ((err = this._validChannel(channel))) {
-		return callback && callback(err);
+
+	if (isInvalidChannel(channel)) {
+		return callback && callback(new Error(invalidChannel));
 	}
 	else {
 		// Get the relay
@@ -56,21 +62,10 @@ Relay.prototype._setValue = function(channel, value, callback) {
 	}
 };
 
-Relay.prototype._validChannel = function(channel) {
-	var self = this;
-	if (!(channel > 0 || channel <= this.currentStates.length)) {
-		var err = new Error("Invalid relay channel. Must be 1 or 2.");
-		self.emit('error', err);
-		return err;
-	}
-	return null;
-};
-
 // Gets the state of the specified relay channel
 Relay.prototype.getState = function(channel, callback) {
-	var err;
-	if ((err = this._validChannel(channel))) {
-		return callback && callback(err);
+	if (isInvalidChannel(channel)) {
+		return callback && callback(new Error(invalidChannel));
 	}
 	else {
 		callback && callback(null, this.currentStates[channel - 1]);

test/test.js

@@ -1,32 +1,58 @@
 var tessel = require('tessel');
 var relayDriver = require('../');
 var relayPort = tessel.port.A;
-var testPort = tessel.port['B'];
+var testPort = tessel.port.B;
 
 var pinout = testPort.digital[0];
 var pinin = testPort.digital[1];
 
 var relay = relayDriver.use(relayPort);
 
-console.log('1..5');
+console.log('1..11');
 
 relay.on('ready', function () {
   console.log('# ready');
   console.log('ok');
 
   var channel = 1;
+  var boundOff = relay.turnOff.bind(relay);
+  var boundOn = relay.turnOn.bind(relay);
 
   setup(function() {
-    testHelper(relay.turnOff.bind(relay), channel, 1, function() {
-      testHelper(relay.turnOn.bind(relay), channel, 0, function() {
-        testHelper(relay.turnOff.bind(relay), channel, 1, function() {
+    testHelper(boundOff, channel, 1, function() {
+      testHelper(boundOn, channel, 0, function() {
+        testHelper(boundOff, channel, 1, function() {
           pinout.write(1, function() {
-            testHelper(relay.turnOn.bind(relay), channel, 1);
+            testHelper(boundOn, channel, 1);
           });
         });
       });
     });
   });
+
+  relay._setValue(0, 1, function(error) {
+    console.log(error !== null ? 'ok' : 'not ok');
+  });
+
+  relay._setValue(3, 1, function(error) {
+    console.log(error !== null ? 'ok' : 'not ok');
+  });
+
+  relay.getState(0, function(error) {
+    console.log(error !== null ? 'ok' : 'not ok');
+  });
+
+  relay.getState(3, function(error) {
+    console.log(error !== null ? 'ok' : 'not ok');
+  });
+
+  relay.getState(1, function(error) {
+    console.log(error === null ? 'ok' : 'not ok');
+  });
+
+  relay.getState(2, function(error) {
+    console.log(error === null ? 'ok' : 'not ok');
+  });
 });
 
 function setup(cb) {
@@ -61,4 +87,4 @@ function testHelper(relayFunc, channel, expectedValue, cb) {
 
 relay.on('latch', function(channel, value) {
   console.log('# latch on channel ' + channel + ' switched to', value);
-});
+});