fixing issue with empty strings not being a valid option value

Makefile

@@ -11,8 +11,11 @@ test:
 	./node_modules/.bin/jshint lib/* --config test/jshint/config.json
 	@NODE_ENV=test ./node_modules/.bin/mocha --recursive --reporter spec --timeout 3000 test
 
-test-cov:
+test-lcov:
 	@NODE_ENV=test ./node_modules/.bin/mocha --require blanket --recursive --timeout 3000 -R mocha-lcov-reporter test
+
+test-cov:
+	@NODE_ENV=test ./node_modules/.bin/mocha --require blanket --recursive --timeout 3000 -R travis-cov test
 
 test-cov-html:
 	@NODE_ENV=test ./node_modules/.bin/mocha --require blanket --recursive --timeout 3000 -R html-cov test > test/coverage.html

lib/opter.js

@@ -160,7 +160,16 @@ module.exports = function (options, appVersion) {
 	for (optName in options) {
 		if (options.hasOwnProperty(optName)) {
 			option = options[optName];
-			var value = commander[optName] || process.env[optName.replace(/\./g, '_')] || path.get(configFile, optName) || option.defaultValue;
+			var value = commander[optName];
+			if (value === undefined) {
+				value = process.env[optName.replace(/\./g, '_')];
+				if (value === undefined) {
+					value = path.get(configFile, optName);
+					if (value === undefined) {
+						value = option.defaultValue;
+					}
+				}
+			}
 			if (option.hasOwnProperty('type')) {
 				switch (option.type) {
 

package.json

@@ -4,7 +4,7 @@
 	"contributors": [
 		"Mac Angell <mac.ang311@gmail.com>"
 	],
-	"version": "0.6.0",
+	"version": "0.6.1",
 	"dependencies": {
 		"commander": "2.x.x",
 		"underscore": "1.x.x",
@@ -14,6 +14,7 @@
 		"mocha": "1.x.x",
 		"jshint": "0.x.x",
 		"blanket": "1.0.x",
+		"travis-cov": "0.2.x",
 		"rewire": "2.x.x",
 		"coveralls": "2.x.x",
 		"mocha-lcov-reporter": "0.x.x"
@@ -30,7 +31,7 @@
 		"url": "https://github.com/mac-/opter"
 	},
 	"scripts": {
-		"test": "make test && make test-cov | ./node_modules/coveralls/bin/coveralls.js",
+		"test": "make test && make test-cov && make test-lcov | ./node_modules/coveralls/bin/coveralls.js",
 		"blanket": {
 			"pattern": "//^((?!\/node_modules\/)(?!\/test\/).)*$/ig",
 			"onlyCwd": true,

test/opter.test.js

@@ -78,6 +78,23 @@ describe('Opter Unit Tests', function() {
 		done();
 	});
 
+	it('should read empty string values from args', function(done) {
+
+		setCommandLineArgsAndEnvVars([
+			'node', './test/opter.test.js',
+			'--my-option-from-args1', ''
+		]);
+
+		var cfg = opter({
+			myOptionFromArgs1: {
+				defaultValue: 'default1',
+				argument: 'string'
+			}
+		}, '0.1.0');
+		assert.strictEqual(cfg.myOptionFromArgs1, '', 'myOptionFromArgs1 is an empty string');
+		done();
+	});
+
 	it('should read boolean values from args', function(done) {
 
 		setCommandLineArgsAndEnvVars([