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Fetch local files with Node.js

In a browser environment fetching a local file is quite trivial: one just need to start a server (using MAMP, XAMP, Mac's Python server, etc...), and then doing:
fetch("./foo.txt").then(etc...)
However, in Node.js this simple task has been a challenge. I've tried the same snippet using Node 18 (which comes with an experimental fetch API), but I'm always getting an invalid URL error:
TypeError: Failed to parse URL from foo.bar
[cause]: TypeError [ERR_INVALID_URL]: Invalid URL
I've tried installing node-fetch, but I'm getting the same error. I could start a local server for node like http-server, but it tells me to go to http://localhost:8080 to see the server, that is, using the browser, but the issue is that I can do that without node, using only a node build is the whole point.
My question is: is it possible to fetch a local file in a node build (Sublime Text, VS Code etc...), without using a browser? (note: I can do it with fs, but in my question I'd like to discuss fetch only)

My question is: is it possible to fetch a local file in a node build (Sublime Text, VS Code etc...), without using a browser? (note: I can do it with fs, but in my question I'd like to discuss fetch only)
The Node.js implementation of fetch does not currently support file: scheme URLs…
fetch("file:///tmp/123").then(r => r.text()).then(d => console.log(d));
reports:
Error: not implemented... yet...
…nor (it appears) does it resolve a relative path to a file: scheme URI.
You should use the fs module.

Downloading text file using curl in HTML

I am trying to download text file from server to local directory.
If I execute following curl command it copies myfile.txt from server and saves in same directory as newfile.txt.:
curl -o newfile.txt http://myserverip/myfile.txt
I want to automate this by running the command from javascript while loading the webpage.
For example if I open an html page (which runs a javascript) like http://myserverip/getnewfile.html in the browser the myfile.txt from the server should be copied to newfile.txt in the loacl directory.
Can anyone help me to write javascript to execute the curl command?
Please note that the server in local area network and router is configured to allow connections only from white-listed mac ids of local machines so there is no any authentication required to connect to server.

You can't run local command-line commands from JavaScript, because that would be a massive security vulnerability. The tool you want to use for this is either window.open (to open a tab with the file in order to cause the browser to download it) or the fetch API (to retrieve the file for use in JavaScript).

Why can't I load up a local JSON file with AngularJS $http?

I am trying to load up local file(todo.json) that is in the same folder as my webpage with the following line:
$http.get("todo.json").success( function( data ){ //Do Some logic});
But I get the following error message in the Javascript console:
Error: Failed to execute 'send' on 'XMLHttpRequest': Failed to load 'file:///C:/Users/quickCoder/Desktop/HTML5Apps/todo.json'.
...
As mentioned, the index.html file consisting of this code is in the same HTML5Apps folder as todo.json. Any suggestions ?

I think you need a running webserver that serves your files and the json file have to be in the folder of your server.
You can use a server like node-serve. It's easy to run once installed just type serve in your terminal.
[...] Now the protocol for a local file is not http:// but file://. Therefore, you cannot do a direct AJAX request from a local file. The same applies to many other APIs available through JavaScript, which can only request access through the HTTP protocol. This is because of the Web's security model, which we'll discuss in another article.
source of the quote mdn

How to give relative path in .js on linux platform?

I have Web UI developed in simple HTML and .js with lighttpd as web server and it is on linux based device.
I need to keep my main.html file in root directory and javascript files in js folder.
While running program it reads the javascript from js folder and the javascript accessing config files from other directories (/etc/config/myconfig). While accessing this file application giving error as 403 since I am using XMLHttpRequest, but it works when I keep myconfig file in root directory i.e with the main.html.
Please suggest is there any way to tell javascript to read file from /etc/config directory.

Error 403 :
403 Forbidden
The request was a valid request, but the server is refusing to respond to it.[2] Unlike a 401 Unauthorized response, authenticating will make no difference.[2] On servers where authentication is required, this commonly means that the provided credentials were successfully authenticated but that the credentials still do not grant the client permission to access the resource (e.g., a recognized user attempting to access restricted content).
You need give your script access to read from the directory(/etc/config).
Read about chmod/chown commands.

D3.js: Treemap doesn't load from JSON file

I am trying to run this very example of a treemap on localhost, but I can't load the JSON file (which, by the way, is the same JSON file that the example uses).
The console returns the next error in Google Chrome:
XMLHttpRequest cannot load file:///C:/Users/Usuario/Downloads/d3/flare.json. Cross origin requests are only supported for HTTP.
The JSON file is in the same folder as the html file.
Thanks in advance for your help.

You cannot load local files because of the security policy. To quote the D3 website:
When developing locally, note that your browser may enforce strict permissions for reading files out of the local file system. If you use d3.xhr locally (including d3.json et al.), you must have a local web server. For example, you can run Python's built-in server:
python -m SimpleHTTPServer 8888 &
or for Python 3+
python -m http.server 8888 &
Once this is running, go to http://127.0.0.1:8888/.

If people working d3.js on the xampp or wamp they can run their html file as like php file by starting the server.
I found the same issue then I started the wampp server then the file get loaded successfully without any issue like "XmlHttpRequest Access control allow orgin".
I am working in WAMP. I hope same thing for XAMPP, but I am not sure...