Add a utility to convert file URL or path to one of them?

[fisker]

What is the problem this feature will solve?

It's a nice way to accept both URL and path string in API, but we need covert it to either string or URL, it would be nice to have a built-in method to do this.

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

For converting to string:

Maybe add path.from(URL | string)? @sindresorhus proposed here.

For converting to URL:

url.from(URL | string)

I'm not sure, since URL is a standard, I guess adding method URL object won't be acceptable, maybe to node:url module?

What alternatives have you considered?

No response

[aduh95]

We have a toPathIfFileURL internal API already, maybe we could expose it in the node:url module

node/lib/internal/url.js

Lines 1558 to 1562 in 38b7961

	function toPathIfFileURL(fileURLOrPath) {
	if (!isURLInstance(fileURLOrPath))
	return fileURLOrPath;
	return fileURLToPath(fileURLOrPath);
	}

For converting to URL:

url.from(URL | string)

I don't think there is any reliable way to check if a string is a path or a file URL... I'm afraid the best option here is to assume that a string is a path and call pathToFileURL(string) (which is what is doing Node.js internally as well) – or if you prefer to assume strings are URLs in your application, call new URL(string).

[sindresorhus]

We have a toPathIfFileURL internal API already, maybe we could expose it in the node:url module

Wouldn't it be more natural to have it in node:path, since we want to convert it to a path? My proposal for path.from() was inspired by Array.from and Buffer.from type methods.

[sindresorhus]

I don't think there is any reliable way to check if a string is a path or a file URL...

To be clear, the string in that example is meant to be a file path, not a string file URL.

Example usage:

import path from 'node:path';

// Passthrough
path.from('/Users/sindresorhus/dev');
//=> '/Users/sindresorhus/dev'

path.from(new URL('file:///Users/sindresorhus/dev'));
//=> '/Users/sindresorhus/dev'

[benjamingr]

Is this what you had in mind in terms of semantics? benjamingr@0704851#diff-6610c8d452ba38a0db8c591e06af555bc7755ace17065a066c853ffcc5271559R7-R20

[fisker]

Yes, that's what I want.

[benjamingr]

@aduh95 wdyt about an implementation that does that? ( #41521 (comment) )

[aduh95]

@aduh95 wdyt about an implementation that does that? ( #41521 (comment) )

I don't think we'll get consensus landing in core something that treats differently a string depending on if it starts with file: or not – what if the user meant ./file:/ (i.e. they really have a local directory named file:)?

The workarounds that come to mind are:

• only support absolute paths – or require relative paths to start with a . (like in require calls).
• always treat a string as a path.
• publish this as an npm module instead (I think npm module would get away with not supporting having directory named file:).

Any combination of the above would address my concern, but I'm open to other ideas if someone thinks of something else.

[benjamingr]

@aduh95 I think it's safe to say "if this can be an npm module, sindre has already probably published one" :D Making small useful modules kind of their thing.

Edit: lol found it https://www.npmjs.com/package/file-url
Edit2: actually that's the other side of conversion