[patch] include aliases when setting defaults for booleans

Fixes #29

index.js

@@ -135,10 +135,14 @@ module.exports = function (args, opts) {
 		});
 	}
 
+	// Set booleans to false by default.
 	Object.keys(flags.bools).forEach(function (key) {
-		setArg(key, defaults[key] === undefined ? false : defaults[key]);
+		setArg(key, false);
+	});
+	// Set booleans to user defined default if supplied.
+	Object.keys(defaults).filter(isBooleanKey).forEach(function (key) {
+		setArg(key, defaults[key]);
 	});
-
 	var notFlags = [];
 
 	if (args.indexOf('--') !== -1) {

test/bool.js

@@ -154,3 +154,19 @@ test('boolean using something similar to true', function (t) {
 	t.same(result, expected);
 	t.end();
 });
+
+test('supplied default for boolean using alias', function (t) {
+	var argv = parse(['moo'], {
+		boolean: ['bool'],
+		alias: { bool: 'b' },
+		default: { b: true },
+	});
+
+	t.deepEqual(argv, {
+		bool: true,
+		b: true,
+		_: ['moo'],
+	});
+
+	t.end();
+});