[Fix] .has should not return true on a falsy node

Fixes #20

index.js

@@ -279,6 +279,10 @@ Traverse.prototype.get = function (ps) {
 /** @type {(ps: PropertyKey[]) => boolean} */
 Traverse.prototype.has = function (ps) {
 	var node = this.value;
+	// TODO: remove ps.length check
+	if (!node && ps.length > 0) {
+		return false;
+	}
 	for (var i = 0; node && i < ps.length; i++) {
 		var key = ps[i];
 		if (!hasOwnProperty.call(node, key) || (!this.options.includeSymbols && typeof key === 'symbol')) {

test/has.js

@@ -14,6 +14,10 @@ test('has', function (t) {
 	t.equal(traverse(obj).has(['a']), true);
 	t.equal(traverse(obj).has(['a', 2]), false);
 
+	// TODO: change this to `false`
+	t.equal(traverse(undefined).has([]), true, 'traversing a non-object somehow returns true for no paths');
+	t.equal(traverse(undefined).has(['my', 'path']), false, 'traversing a non-object does not have any paths');
+
 	t.test('symbols', { skip: !v.hasSymbols }, function (st) {
 		/* eslint no-restricted-properties: 1 */
 		var globalSymbol = Symbol.for('d');