Node: OSX "working directory" mismatch

[evantahler]

• node v5.9.1:
• OSX:
• El Capitan:

On OSX, if you are a temporary directory, as generated via require('os').tmpDir() (like /var/folders/ry/c05q3yxs1q98yps6h2_g3gn00000gn/T) It's possoble that the various ways of determining your path do not match:

• __dirname => /private/var/folders/ry/c05q3yxs1q98yps6h2_g3gn00000gn/T
• process.env.PWD => /var/folders/ry/c05q3yxs1q98yps6h2_g3gn00000gn/T
• process.cwd() => /private/var/folders/ry/c05q3yxs1q98yps6h2_g3gn00000gn/T

[evantahler]

I've only seen this behavior when working inside a temporary directory, and only on OSX. process.env.PWD seems to be the odd-man out.

[evanlucas]

process.cwd() is using the realpath here so, since on OS X, /var is a symlink to /private/var, it is technically correct. Although, I'm not sure why __dirname is not resolving the real path

[jasnell]

Looking at the example, __dirname and process.cwd() show the same value, which looks correct. process.env.PWD is not going to resolve the symlink, so these values are correct.

[evantahler]

The interesting thing here is that the path I CD'd into via bash _only_ agrees with process.env.PWD, and it looks like the node internal commands (__dirname and process.cwd()) agree internally, but disagree with the actual shell.

This is certainly a strange edge case, as the OSX /tmp directory is a confusing mess of symlinks.

[evanlucas]

@evantahler do you have a reproducible test case that exhibits this behavior? (and preferably does not depend on any external modules)

[evantahler]

Hi other Evan, sure thing!

In a console:

 node -e "console.log( require('os').tmpDir() )"

You'll get back something like /var/folders/ry/c05q3yxs1q98yps6h2_g3gn00000gn/T

cd /var/folders/ry/c05q3yxs1q98yps6h2_g3gn00000gn/T 

In that temp directory run the following file:

// test.js
console.log('__dirname => ' + __dirname);
console.log('process.env.PWD => ' + process.env.PWD);
console.log('process.cwd() =>' + process.cwd());

Your output will indicate that you don't have a match, IE:

> node test.js
__dirname => /private/var/folders/ry/c05q3yxs1q98yps6h2_g3gn00000gn/T
process.env.PWD => /var/folders/ry/c05q3yxs1q98yps6h2_g3gn00000gn/T
process.cwd() =>/private/var/folders/ry/c05q3yxs1q98yps6h2_g3gn00000gn/T

[evanlucas]

Thanks @evantahler. I could reproduce using bash, but not with fish. It looks like bash isn't resolving the symlink for $PWD. As a workaround, one could simply run process.env.PWD through fs.realpath or fs.realpathSync and you should be in business.

I am going to go ahead and close as it doesn't appear to be an issue in core. Thanks!