ng commands always return "This: not found" on Windows WSL 2 - node.js

Question

I'm new on Angular, and I'm not able to run ng commands on WSL version 2.
I installed Angular CLI running:
npm install -g #angular/cli
After that I created a new npm project folder and a package.json running:
npm init
But every ng command returns:
/mnt/c/Users/xxxxxx/AppData/Roaming/npm/node_modules/node/bin/node: 1: This: not found`
I installed Node.js on Windows with an executable (so under PowerShell, everything works as expected). Am I wrong with this?

Answer 1

I installed Node.js on Windows with an executable before (so on PowerShell works), am I wrong with this?
Not, necessarily "wrong", but it's likely part of the problem. But you are certainly correct to question it and provide it as a critical detail in your post!
While WSL can launch Windows executables, keep in mind that those Windows executables (npm in this case) typically only understand Windows paths, processes, environment variables, etc.
npm on the Windows version of Node is a bit unusual, thought. It provides a Bash shell script, which is actually what is being called when you run npm under WSL. That shell script was originally designed for Cygwin and Git Bash, but I see that Node recently added checks in it for WSL as well. Before that, even (the Windows version of) npm itself would have issues under WSL.
But regardless of whether they've fixed npm to work under WSL, then you run into the next level of issues since Angular hasn't modified ng to detect when it is running under WSL.
Without having dug into the source code, ng is going to see that it is running under the Windows version of Node and try to use Windows tools and paths. In my test under WSL (using the Windows version of Node/npm), what seems to happen is that ng new project tries to start CMD.exe. Since it is running under the Windows version of Node, it naturally assumes that CMD.exe is available.
And it is, but starting CMD.exe from inside WSL will attempt to start in a UNC path (\\wsl$\<distroname>\path\to\current\project\dir or \\wsl.localhost\...). CMD doesn't support UNC paths, so it defaults to the Windows directory itself, and I get:
EPERM: operation not permitted, mkdir 'C:\Windows\project'
While you are getting a different error, to be sure, it's almost certainly related to this root issue.
To make a long story longer, see my advice in the question, How to organize programming languages and libraries in WSL and Windows 10.
To summarize it, when using development tools, either:
Use the Windows version of the toolchain (editor, commandline, SDK, tools, etc.)
Or use all-Linux versions of the toolchain.
Also, though, be careful with Node specifically. You can install:
The Windows version of Node for when you are using Windows tools
The Linux version of Node for when you are using WSL tools
But when you are running in WSL/Linux, make sure that the Linux version of npm and node appear first in the path, before the Windows version. This is, again, because of the fact that the Windows version provides that shell script. If the Windows version comes before the Linux version in your Linux PATH, then you will continue to have issues since the Windows npm will get called under WSL (as it is now).