From 1c2ef49f8ebcaffc37ee3a8f01a76259b727adb8 Mon Sep 17 00:00:00 2001
From: Ari Porad <ari@ariporad.com>
Date: Sat, 20 Feb 2016 15:13:46 -0800
Subject: [PATCH 1/2] perf(cd): only run `stat` once

---
 src/cd.js | 22 ++++++++++++++--------
 1 file changed, 14 insertions(+), 8 deletions(-)

diff --git a/src/cd.js b/src/cd.js
index b7b9931..e70e37d 100644
--- a/src/cd.js
+++ b/src/cd.js
@@ -16,13 +16,19 @@ function _cd(options, dir) {
       dir = common.state.previousDir;
   }
 
-  if (!fs.existsSync(dir))
-    common.error('no such file or directory: ' + dir);
-
-  if (!fs.statSync(dir).isDirectory())
-    common.error('not a directory: ' + dir);
-
-  common.state.previousDir = process.cwd();
-  process.chdir(dir);
+  // This complexity is so that we only stat once.
+  var error = null;
+  try {
+    var stat = fs.statSync(dir);
+    if(stat.isDirectory()) {
+      common.state.previousDir = process.cwd();
+      process.chdir(dir);
+    } else {
+      error = 'not a directory: ' + dir;
+    }
+  } catch (e) {
+    error = 'no such file or directory: ' + dir;
+  }
+  if (error) common.error(error);
 }
 module.exports = _cd;

From 48a3aade2e64f1b1f2cf0e4d3613ce52dca45c19 Mon Sep 17 00:00:00 2001
From: Nate Fischer <ntfschr@gmail.com>
Date: Sun, 28 Feb 2016 22:00:22 -0800
Subject: [PATCH 2/2] Improved cd performance and fix error messages

---
 src/cd.js | 23 ++++++++++++-----------
 1 file changed, 12 insertions(+), 11 deletions(-)

diff --git a/src/cd.js b/src/cd.js
index e70e37d..51bc057 100644
--- a/src/cd.js
+++ b/src/cd.js
@@ -16,19 +16,20 @@ function _cd(options, dir) {
       dir = common.state.previousDir;
   }
 
-  // This complexity is so that we only stat once.
-  var error = null;
   try {
-    var stat = fs.statSync(dir);
-    if(stat.isDirectory()) {
-      common.state.previousDir = process.cwd();
-      process.chdir(dir);
-    } else {
-      error = 'not a directory: ' + dir;
-    }
+    var curDir = process.cwd();
+    process.chdir(dir);
+    common.state.previousDir = curDir;
   } catch (e) {
-    error = 'no such file or directory: ' + dir;
+    // something went wrong, let's figure out the error
+    var err;
+    try {
+      fs.statSync(dir); // if this succeeds, it must be some sort of file
+      err = 'not a directory: ' + dir;
+    } catch (e) {
+      err = 'no such file or directory: ' + dir;
+    }
+    if (err) common.error(err);
   }
-  if (error) common.error(error);
 }
 module.exports = _cd;