path: assert inputs are strings

This commit makes input type checking consistent across all path
functions.

PR-URL: https://github.com/nodejs/node/pull/5348
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Roman Reiss <me@silverwind.io>

1 files changed, 6 insertions, 12 deletions

diff --git a/lib/path.js b/lib/path.js
index b42889ebfc7..000dd2359d6 100644
--- a/lib/path.js
+++ b/lib/path.js
@@ -734,8 +734,7 @@ const win32 = {
 
 
   dirname: function dirname(path) {
-    if (typeof path !== 'string')
-      path = '' + path;
+    assertPath(path);
     const len = path.length;
     if (len === 0)
       return '.';
@@ -839,8 +838,7 @@ const win32 = {
   basename: function basename(path, ext) {
     if (ext !== undefined && typeof ext !== 'string')
       throw new TypeError('"ext" argument must be a string');
-    if (typeof path !== 'string')
-      path = '' + path;
+    assertPath(path);
     var start = 0;
     var end = -1;
     var matchedSlash = true;
@@ -926,8 +924,7 @@ const win32 = {
 
 
   extname: function extname(path) {
-    if (typeof path !== 'string')
-      path = '' + path;
+    assertPath(path);
     var startDot = -1;
     var startPart = 0;
     var end = -1;
@@ -1364,8 +1361,7 @@ const posix = {
 
 
   dirname: function dirname(path) {
-    if (typeof path !== 'string')
-      path = '' + path;
+    assertPath(path);
     if (path.length === 0)
       return '.';
     var code = path.charCodeAt(0);
@@ -1396,8 +1392,7 @@ const posix = {
   basename: function basename(path, ext) {
     if (ext !== undefined && typeof ext !== 'string')
       throw new TypeError('"ext" argument must be a string');
-    if (typeof path !== 'string')
-      path = '' + path;
+    assertPath(path);
 
     var start = 0;
     var end = -1;
@@ -1471,8 +1466,7 @@ const posix = {
 
 
   extname: function extname(path) {
-    if (typeof path !== 'string')
-      path = '' + path;
+    assertPath(path);
     var startDot = -1;
     var startPart = 0;
     var end = -1;