I'm practicing with typescript and I want to write a file using fs module but I don't know if is this a noob question or I'm doing something wrong but my project look like this:
root
-> dir (here are the js result from tsc)
-> src
--> data
---> data.json
--> service
---> service.ts
--> index.ts
-> package.json
-> tsconfig.json
And at service.ts apparently the path is:
let filePath = path.join('./','src','data','data.json') // this works
fs.writeFile(filePath, JSON.stringify(data,null,2), 'utf8', (err)=>{ if(err){ return console.log(err);}})
So I don't know why the path is positioned at the root level
If I try "../data/data.json" I get ENOENT ERROR no such file or directory
Is it ok?
Filesystem operations with relative paths always use the Current Working Directory - a concept explained here: https://en.m.wikipedia.org/wiki/Working_directory
When you run Node.js, you do so while being in a particular directory. For example, scripts such as npm start are usually executed in the root-level directory of a repository/project - this causes all relative paths to resolve starting from there. Note, however, that this may be different in production - it is possible for Docker, PM2, systemd, or any other tool to run your script while being in a different working directory (this can often be configured).
To inspect your current working directory in Node.js, use https://nodejs.org/api/process.html#processcwd
It is also possible to build paths relative to the directory of the JS file. This tutorial shows various examples on how to do that: https://www.digitalocean.com/community/tutorials/nodejs-how-to-use__dirname
It is important to remember that require() uses paths relative to __dirname, but fs resolves relative to CWD.