v18.18.2 -> v18.19.0, v20.5.1 -> v20.6.0 regression: pathToFileURL trims whitespace.

[jgerigmeyer]

Version

v18.19.0, v20.6.0

Platform

Darwin Kernel Version 23.2.0: Wed Nov 15 21:53:18 PST 2023; root:xnu-10002.61.3~2/RELEASE_ARM64_T6000 arm64

Subsystem

url

What steps will reproduce the bug?

import {pathToFileURL} from 'url';

const filename = `test-${String.fromCharCode(0)}`;
console.log(pathToFileURL(filename).toString()); // file:///[...]/test-

How often does it reproduce? Is there a required condition?

always

What is the expected behavior? Why is that the expected behavior?

In Node v18.18.2 and v20.5.1:

import {pathToFileURL} from 'url';

const filename = `test-${String.fromCharCode(0)}`;
console.log(pathToFileURL(filename).toString()); // file:///[...]/test-%00

What do you see instead?

Where prior versions retained the trailing whitespace and returned a pathname ending in /test-%00, starting in v18.19.0 and v20.6.0 the trailing whitespace is removed and results in a pathname ending in /test-.

Additional information

This regression was introduced by optimizations in #48709, specifically the switch from:

const outURL = new URL('file://');
outURL.pathname = encodePathChars(resolved);
return outURL;

To:

resolved = encodePathChars(resolved);
return new URL(`file://${resolved}`);

While these seem equivalent, new URL uses parse, which trims leading and trailing whitespace from the path. In contrast, the earlier method of setting pathname directly does not trim whitespace.

I'm not sure which way is actually preferred, but regardless this was an unexpected (and undocumented) breaking change.

[anonrig]

cc @nodejs/url

[EarlyRiser42]

Hello,
I am interested in contributing to Node.js and would like to work on my first issue. However, I am a bit confused because I thought that most file systems and operating systems do not allow null characters in file names. I have configured that this issue still occurs in Node.js version 22.5.1. If this is indeed a problem that needs to be addressed, may I work on it?

[avivkeller]

You can work on any issue you'd like. If you have a suggested improvement to any part of the code base, feel free to submit a PR.