Fails to parse port 80 only

[thekashifmalik]

When port 80 is in the passed in &str the resulting Url object shows a port value of None.

[SimonSapin]

The idea is to do like browsers’s URLUtils.port which is the empty string when the port number is the same as the scheme’s default (80 for HTTP).

There’s a .port_or_default() convenience method, which may be what you’re looking for.

I’ve considered changing "port" to be the current "port or default", and have a "port is default" boolean or something. What do you think?

[thekashifmalik]

I would defer to the 'Principle of least astonishment' and say that a URL library in isolation should parse all ports equally.

Behaviour like URLUtils.port makes sense to me in a certain environment (like an HTTP browser that has certain common cases), but not in a general URL library. I would certainly encourage the change.

If anything, I would say maybe there should be a method .is_default() -> bool / is_default_for_scheme() -> bool instead of a method that returns an Option<u16> to check for default port values.

[SimonSapin]

I’m very skeptical of this so-called "principle of least astonishment". What’s astonishing to someone might be obvious and make perfect sense to someone else. Everyone has different experience and makes different assumptions.

Regardless, a more important concern for this library is interoperability. Any deviation like this is a potential number of sites that work fine in other browsers but are broken in Servo.

[banool]

6 years later and just reporting that I'm finding myself quite astonished here.

Program:

use url::Url;

fn main() {
    let url1 = Url::parse("http://localhost:5000").unwrap();
    println!("Port: {:?}", url1.port());
    let url2 = Url::parse("http://localhost:80").unwrap();
    println!("Port: {:?}", url2.port());
}

Output:

Port: Some(5000)
Port: None

I think is very unintuitive, I clearly set the port and expect it to be there. Erasing it for 80 is magic.

[banool]

For people coming along later and looking for a better option, use url.port_or_known_default(), it behaves how you'd actually expect it to behave.