Implement errors module

lib/errors/errors.coffee

@@ -0,0 +1,14 @@
+TypedError = require('typed-error')
+log = require('../log/log')
+
+exports.NotFound = class NotFound extends TypedError
+	contructor: (name) ->
+		@message = "Couldn't find #{name}"
+
+exports.handle = (error, exit = true) ->
+	return if not error? or error not instanceof Error
+
+	if error.message?
+		log.error(error.message)
+
+	process.exit(1) if exit

lib/errors/errors.spec.coffee

@@ -0,0 +1,49 @@
+expect = require('chai').expect
+sinon = require('sinon')
+log = require('../log/log')
+errors = require('./errors')
+
+MESSAGES =
+	helloWorld: 'Hello World'
+
+describe 'Errors:', ->
+
+	describe '#handle()', ->
+
+		it 'should log the error message to stderr', ->
+			logErrorStub = sinon.stub(log, 'error')
+			error = new Error(MESSAGES.helloWorld)
+			errors.handle(error, false)
+			expect(logErrorStub).to.have.been.calledWith(MESSAGES.helloWorld)
+			logErrorStub.restore()
+
+		it 'should do nothing if error is not an instance of Error', ->
+			logErrorStub = sinon.stub(log, 'error')
+
+			for item in [
+				undefined
+				null
+				[ 1, 2, 3 ]
+				'Hello'
+				{ message: 'foo bar' }
+			]
+				errors.handle(item, false)
+
+			expect(logErrorStub).to.not.have.been.called
+			logErrorStub.restore()
+
+		checkProcessExitOption = (value, expectations) ->
+			processExitStub = sinon.stub(process, 'exit')
+			logErrorStub = sinon.stub(log, 'error')
+			errors.handle(new Error(MESSAGES.helloWorld), value)
+			expectations(processExitStub)
+			processExitStub.restore()
+			logErrorStub.restore()
+
+		it 'should exit if the last parameter is true', ->
+			checkProcessExitOption true, (processExitStub) ->
+				expect(processExitStub).to.have.been.called
+
+		it 'should not exit if the last parameter is false', ->
+			checkProcessExitOption false, (processExitStub) ->
+				expect(processExitStub).to.not.have.been.called

package.json

@@ -43,6 +43,7 @@
     "open": "0.0.5",
     "inquirer": "~0.8.0",
     "cliff": "~0.1.9",
-    "underscore.string": "~2.4.0"
+    "underscore.string": "~2.4.0",
+    "typed-error": "~0.1.0"
   }
 }