isWebsite does not support internal domains or ports

[mdryden]

Expected Behavior

Urls like "http://localhost:8000" or ""http://foo.com:8080" pass isWebsite() validator.

Actual Behavior

Any URL with a port or without a domain suffix will fail the regex matching.

Steps to Reproduce the Problem

1. Create a string validator which uses isWebsite (eg: validate(MyCommand::myUrl).isNotEmpty().isWebsite()
2. Pass it a value with a port or an internal domain name,

Example Code or Link to a Project

data class MyCommand(
    val url1: String,
    val url2: String,
) : BaseCommand() {
    init {
        validate(this) {
            validate(MyCommand::url1).isNotEmpty().isWebsite()
            validate(MyCommand::url2).isNotEmpty().isWebsite()
        }
    }
}

Json Payload

{
    "url1": "http://localhost/",
    "url2": "http://mydomain.com:8000"
}

Environment

• Valiktor version: 0.12.0
• JDK/JRE version: 17
• Platform/OS: Windows

[mdryden]

You might consider trying to use the URL class to do a bit more validation - here's the solution I came up with since I needed something right away:

fun String.isWebsite(): Boolean {
    return try {
        val url = URL(this)
        return url.host.isNotEmpty() && url.protocol.startsWith("http")
    } catch (e: Throwable) {
        false
    }
}

fun <E> Validator<E>.Property<String?>.isWebsite(): Validator<E>.Property<String?> =
    this.validate(Website) {
        it == null || it.isWebsite()
    }

The URL constructor throws an exception for a completely invalid URL, but it accepts some URLs I wouldn't consider valid (eg: http://), and many which we probably wouldn't consider a website (eg: ftp://foo.bar).

For my purposes, I'm considering a website anything which passes the URL parsing, has a host and starts with http.

Test cases:

http://google.com:8000 - pass
http://localhost - pass
http:// - fail
ftp://foo.bar - fail
http://localhost: - pass (should fail - this solution isn't perfect either).

As noted with test case 5 this solution isn't perfect either but it's close enough for my purposes. I'm not sure if it's appropriate for this library, but maybe it's a helpful starting place if you decide to move forward with this report.