A non-failable initialiser extension for URL that accepts StaticString

URL+StaticString.swift

import Foundation

extension URL {
    /// Initialize with a static string.
    ///
    /// If the `URL` cannot be formed with the string (for example, if the string contains characters that are illegal in a URL, or is an empty string), a precondition failure will trigger at runtime.
    init(staticString: StaticString) {
        guard let url = Self.init(string: String(describing: staticString)) else {
            preconditionFailure("'\(staticString)' does not represent a legal URL")
        }
        self = url
    }
}

Another safe(good?) practice is to have some kind of URLs repository type that is backed up by unit tests in case a wrong URL goes unnoticed.