path.join() changes casing of drive letter starting with 0.11.0

[AlexZeitler]

Running this piece of code on Windows and Node.js 0.10.25 results as shown below.

Code:

var path = require('path');
var join = path.join;
var root = __dirname;
var relativePath = '/relativepath'
var joinedPath = join(root, relativePath);
console.log("root:",__dirname);
console.log("relative path:",relativePath);
console.log("joined path:", joinedPath);

Result (Node.js 0.10.25 on Windows 7 Pro x64):

root: D:\Code\PDMLab\nodetests
relative path: /relativepath
joined path: D:\Code\PDMLab\nodetests\relativepath

Result running the same code on Node.js 0.11.0 and later on Windows 7 Pro x64:

root: D:\Code\PDMLab\nodetests
relative path: /relativepath
joined path: d:\Code\PDMLab\nodetests\relativepath

As you can see, the drive letter now is lower case.

This behavior breaks modules like koa-send when it comes to using joined path instances.

[larryb82]

a05f973

Changed the behaviour of normalize which is used by join: https://github.com/joyent/node/blob/b9bec2031e5f44f47cf01c3ec466ab8cddfa94f6/lib/path.js#L243

[dougwilson]

Modules should be using path.normalize on both strings before trying to directly compare them. koa already fixed this in version 1.2.3 release yesterday.

[create-renegr]

I crushed into the same problem with another plugin I used.

Can you explain why the result of path.join is normalized by default, but the result of path.resolve is not?

I know nothing of the implementation details of the path library, so from a users perspective it seems to me kinda odd, to handle the results (within one library) differently.

Thanks for clarification!

[obastemur]

I have tried a similar .NET Framework methods to see whether they are updating the drive letter to a lower cap on Windows, but they didn't. I don't see a technical necessity behind this update.
notes on #5073

[create-renegr]

Thanks for your effort, but if this is an answer to my question, I did not grasp it. Sorry.

Why are the results handled differently?
Why does one function apply normalize to the result, whereas the other does not?
Is there anything wrong if every return value is being normalized by default to ensure consistency inside the library?

[obastemur]

Is there anything wrong if every return value is being normalized by default to ensure consistency inside the library?

I agree with you on consistency. IMHO I don't see the reason for a normalization that way, especially forcing drive letters to lowercase on Windows. Perhaps, there is a historical reason for that patch or simply not well considered on the bigger picture.

[fluidsonic]

This change also broke our code which _require_s some files using their full path:

require(path.join(__dirname, 'other.js'));

It works fine as long as the _require_d module wasn't already loaded using a relative path. But as soon as the newly loaded module _require_s other modules it loads all of them using a different case for the drive letter and thus all of them are loaded twice.

Simple test case:

console.log('Executing:', __filename);

var path = require('path');

require(__filename);
require(path.join(__filename));

The module _require_s itself which shouldn't do much. The first require uses the full path untouched and the second one uses path.join on the full path.

Expected output:

Executing: C:\some\long\path\test.js

Actual output:

Executing: C:\some\long\path\test.js
Executing: c:\some\long\path\test.js

The module is loaded twice. D'oh.

[migounette]

There is also a side effect with VM functions, in this case as you said you will obtain multiple copies in Module._cache, once you have joined or normalize the path via vm.runInNewContext(fs.readFileSync(... path.normalize(...), ..))

You will have multiple entries in Modules._cache for the same modules if you use relative paths, because the __dirname of the parent has now the drive letter in lowercase

My 2 cents

[zxc122333]

same issue. Some modules are loaded twice.

[pspaulding]

I also ran into an issue with some modules loading more than once, leading to all sorts of issues.

[zxc122333]

@tjfontaine ?