path: reduce type checking on some methods

a465840 added strict type
checking for the methods in the path module. However, dirname(),
basename(), and extname() actually had some undocumented uses
in the wild. This commit loosens the type checking on those
methods.

Fixes: #1215
PR-URL: #1216
Reviewed-By: Rod Vagg <rod@vagg.org>

lib/path.js

@@ -302,8 +302,6 @@ win32._makeLong = function(path) {
 
 
 win32.dirname = function(path) {
-  assertPath(path);
-
   var result = win32SplitPath(path),
       root = result[0],
       dir = result[1];
@@ -323,8 +321,6 @@ win32.dirname = function(path) {
 
 
 win32.basename = function(path, ext) {
-  assertPath(path);
-
   if (ext !== undefined && typeof ext !== 'string')
     throw new TypeError('ext must be a string');
 
@@ -338,7 +334,6 @@ win32.basename = function(path, ext) {
 
 
 win32.extname = function(path) {
-  assertPath(path);
   return win32SplitPath(path)[3];
 };
 
@@ -536,8 +531,6 @@ posix._makeLong = function(path) {
 
 
 posix.dirname = function(path) {
-  assertPath(path);
-
   var result = posixSplitPath(path),
       root = result[0],
       dir = result[1];
@@ -557,8 +550,6 @@ posix.dirname = function(path) {
 
 
 posix.basename = function(path, ext) {
-  assertPath(path);
-
   if (ext !== undefined && typeof ext !== 'string')
     throw new TypeError('ext must be a string');
 
@@ -572,7 +563,6 @@ posix.basename = function(path, ext) {
 
 
 posix.extname = function(path) {
-  assertPath(path);
   return posixSplitPath(path)[3];
 };
 

test/parallel/test-path.js

@@ -270,13 +270,16 @@ typeErrorTests.forEach(function(test) {
   fail(path.resolve, test);
   fail(path.normalize, test);
   fail(path.isAbsolute, test);
-  fail(path.dirname, test);
   fail(path.relative, test, 'foo');
   fail(path.relative, 'foo', test);
-  fail(path.basename, test);
-  fail(path.extname, test);
   fail(path.parse, test);
 
+  // These methods should throw a TypeError, but do not for backwards
+  // compatibility. Uncommenting these lines in the future should be a goal.
+  // fail(path.dirname, test);
+  // fail(path.basename, test);
+  // fail(path.extname, test);
+
   // undefined is a valid value as the second argument to basename
   if (test !== undefined) {
     fail(path.basename, 'foo', test);