added GpioPlugin with basic functionality (execute/listenEvents)

 + tests

src/plugins/GpioPlugin/GpioPlugin.js

@@ -0,0 +1,97 @@
+/**
+* This module is used to handle tasks and events directly with GPIO Ports on Raspberry Pi.
+* It is used within pi@home.
+*
+* @class GpioPlugin
+*/
+
+var onOff;
+
+/**
+* The constructor can be used to change settings of GpioPlugin by using options.
+*
+* @method GpioPlugin
+* @param {opts} opts The options:
+*	- 'gpioPlugin' = Plugin for using onOff functionality (can be set for testing i.e.)
+*/
+function GpioPlugin(opts) {
+	if(opts==='undefined') {
+		onOff = require('onoff').Gpio;		
+	}
+
+	if(opts.gpioPlugin) {
+		onOff = opts.gpioPlugin;
+	} else {
+		onOff = require('onoff').Gpio;
+	}
+	return this;
+}
+
+/**
+* This method is used to execute a pi@home command concerning GPIO Ports.
+*
+* @method execute
+* @param {opts} opts The options:
+*	- 'direction' = 'in' or 'out'
+*	- 'pin' = the pin number on RPi GPIOs
+*	- 'value' = the value for direction 'out'
+*/
+function execute(opts) {
+	if(opts==='undefined') {
+		throw new Error("arguments for execute missing");
+	}
+	if(!opts.direction) {
+		throw new Error("option 'direction' is missing");
+	}
+	if(!opts.pin) {
+		throw new Error("option 'pin' is missing");
+	}
+
+	if(opts.direction === 'out') {
+		if(!opts.value) {
+			throw new Error("option 'value' is missing for pin output");
+		}
+		this.sendOutput(opts.pin, opts.value);
+	}
+}
+
+/**
+* This method is used to send a output to a GPIO pin.
+*
+* @method sendOutput
+* @param {int} pin The pin on which the signal/value should be send.
+* @param {int} value The value which should be send (1 = HIGH, 0 = LOW).
+*/
+function sendOutput(pin, value) {
+		var gpioPin = onOff.Gpio(pin, 'out');
+		gpioPin.writeSync(value);
+		gpioPin.unexport();
+}
+
+/**
+* This method listens on a GPIO pin and throws events with eventId when value of pin changes.
+*
+* @method listenEvents
+* @param {int} eventId The eventId like configured in event config.
+* @param {opts} opts The opts must contain 'pin' on which should be listened.
+*/
+function listenEvents(eventId, opts) {
+	if(!opts.pin) {
+		throw new Error("option 'pin' is missing");
+	}
+	//TODO check eventId = valid int
+	var listenPort = new onOff.Gpio(opts.pin, 'in', 'both', {persistentWatch: true});
+	var eventIdString = eventId + '';
+
+	listenPort.watch(function(err, value) {
+		process.emit(eventId+'', value);
+	});
+}
+
+// If we're running under Node, 
+if(typeof exports !== 'undefined') {
+	exports.execute = execute;
+	exports.GpioPlugin = GpioPlugin;
+	exports.sendOutput = sendOutput;
+	exports.listenEvents = listenEvents;
+}

test/plugins/Gpio/GpioPlugin-test.js

@@ -0,0 +1,124 @@
+var gpioPlugin = require('./../../../src/plugins/GpioPlugin/GpioPlugin');
+var assert = require('chai').assert;
+var sinon = require('sinon');
+
+describe('GPIO-tests', function(){
+
+	it("should throw error because one or more options are missing", function() {
+		var gpio = gpioPlugin.GpioPlugin({'GpioPlugin':null});
+		var error;
+		//without arguments
+		try {
+			gpio.execute();
+		} catch (err) {
+			error = err;
+		}
+		assert.include(error.message, "Cannot read property 'direction' of undefined");
+
+		//empty arguments
+		error = null;
+		try {
+			gpio.execute({});
+		} catch (err) {
+			error = err;
+		}
+		assert.include(error.message, "option 'direction' is missing");
+
+		//missing pin
+		error = null;
+		try {
+			gpio.execute({'direction':'in'});
+		} catch (err) {
+			error = err;
+		}
+		assert.include(error.message, "option 'pin' is missing");
+
+		//value missing
+		error = null;
+		try {
+			gpio.execute({'direction':'out','pin':17});
+		} catch (err) {
+			error = err;
+		}
+		assert.include(error.message, "option 'value' is missing");
+	});
+
+	it("should execute function 'sendOutput' with correct values", function() {
+		//Preparation
+		var onOff = require('onoff').Gpio;
+
+		var gpioMock = {
+			writeSync:function(value) {
+				assert.equal(value,1);
+			},
+			unexport:function() {
+			}
+		};
+
+		var onOffMock = {
+			Gpio:function(pin,direction) {
+				assert.equal(pin,18);
+				assert.equal(direction,'out');
+				return gpioMock;
+			}
+		};
+
+		gpio = gpioPlugin.GpioPlugin({'gpioPlugin':onOffMock});
+
+		var spy1 = sinon.spy(onOffMock, "Gpio");
+		var spy2 = sinon.spy(gpioMock, "writeSync");
+		var spy3 = sinon.spy(gpioMock, "unexport");
+
+		//execution
+		gpio.execute({'direction':'out','pin':18,'value':1});
+
+		//assertion
+		assert(spy1.calledOnce, "method Gpio should be called");
+		assert(spy2.calledOnce, "method writeSync should be called");
+		assert(spy3.calledOnce, "method unexport should be called");
+	});
+
+	it("should check functionality of method 'listenEvents'", function() {
+		//Preparation
+		var eventId = 1234;
+		var onOff = require('onoff').Gpio;
+		var success = false;
+
+		process.on("1234", function(value) {
+			if(value===1) {
+				success = true;
+			}
+		});
+
+		var gpioMock = {
+			watch:function(callback) {
+				callback(false, 1);
+			}
+		};
+
+		var onOffMock = {
+			Gpio:function(pin,direction,edge,options) {
+				assert.equal(pin,18);
+				assert.equal(direction,'in');
+				assert.equal(edge,'both');
+				assert.equal(options.persistentWatch,true);
+				return gpioMock;
+			}
+		};
+
+		gpio = gpioPlugin.GpioPlugin({'gpioPlugin':onOffMock});
+
+		var spy1 = sinon.spy(onOffMock, "Gpio");
+		var spy2 = sinon.spy(gpioMock, "watch");
+
+
+		//execution
+		gpio.listenEvents(eventId, {'pin':18});
+
+		//assertion
+		assert.equal(success, true, "should return correct event with correct value");
+
+		//after test
+		process.removeAllListeners("1234");
+	});
+});