path.resolve 与 Node.js 中的相对路径？

Question

I often see examples in node like:

process.env.GOOGLE_APPLICATION_CREDENTIALS = path.resolve(__dirname, 'credentials.json')

I understand that path is a useful module when dealing with more complex situations, but in this case, why not just use

process.env.GOOGLE_APPLICATION_CREDENTIALS = './credentials.json'

?

Answer 1

From the Documentation :

The directory name of the current module. This is the same as the path.dirname() of the __filename.

This means when using this:

process.env.GOOGLE_APPLICATION_CREDENTIALS = './credentials.json'

NodeJS will look for credentials.json in the current working directory

While when using this:

process.env.GOOGLE_APPLICATION_CREDENTIALS = path.resolve(__dirname, 'credentials.json')

NodeJS will look for credentials.json in the same directory where this module is

Lets say you have a directory structure like this:

/
+-- home
|   +-- USERNAME
|       +-- project
|           +-- index.js
|           +-- credentials.json

if you run the following commands (from the root directory / ):

cd home/USERNAME/project
node index.js

The code will work just fine in both cases.

But if you run it like this

node home/USERNAME/project/index.js

With path.resolve you'll get: home/USERNAME/project/credentials.json which is correct

and without it you'll get: ./credentials.json , which is wrong as your current directory is / .