more useable fs/promises backtraces on error

[axkibe]

What is the problem this feature will solve?

Take following minimal test case:

import fs from 'node:fs/promises';
async function b( ) { return await fs.readFile( 'inexistent' ); }
async function a( ) { return await b( ); }
await a( );

the output will be:

      internalBinding('errors').triggerUncaughtException(
                                ^

[Error: ENOENT: no such file or directory, open 'inexistent'] {
  errno: -2,
  code: 'ENOENT',
  syscall: 'open',
  path: 'inexistent'
}

Node.js v20.8.0

so no hint where.

What is the feature you are proposing to solve the problem?

I used to wrap all fs call to something like this:

import fs from 'node:fs/promises';
async function myread( filename )
{
    try { return await fs.readFile( filename ); }
    catch( e ) { throw new Error( 'cannot read "' + filename + '"' ); }
}
async function b( ) { return await myread( 'inexistent' ); }
async function a( ) { return await b( ); }
await a( );

So the error stack becomes:

file:///home/axel/xtest2/x2.mjs:6
	catch( e ) { throw new Error( 'cannot read "' + filename + '"' ); }
	                   ^

Error: cannot read "inexistent"
    at myread (file:///home/axel/xtest2/x2.mjs:6:21)
    at async b (file:///home/axel/xtest2/x2.mjs:8:30)
    at async a (file:///home/axel/xtest2/x2.mjs:9:30)
    at async file:///home/axel/xtest2/x2.mjs:10:1

Suggestion: IMO it would be beneficial for node to make these more userfriendly/useful backtraces by default without having to wrap all fs calls by the user?

What alternatives have you considered?

explained above, wrap the fs calls with try/catch blocks all myself, it's very possible, likely someone wrote a npm package anyway, likely several, but IMO this is one of the things the core should come with making the entry easier for new people.

[sapphi-red]

I guess my PR (#49849) implements this.