publicsuffix - Public Suffix Checking Maven Central

A "public suffix" is one under which Internet users can (or historically could) directly register names. Some examples of public suffixes are .com, .co.uk and pvt.k12.ma.us. The Public Suffix List is a list of all known public suffixes. The Public Suffix List is an initiative of Mozilla, but is maintained as a community resource. It is available for use in any software, but was originally created to meet the needs of browser manufacturers. It allows browsers to, for example:

  • Avoid privacy-damaging "supercookies" being set for high-level domain name suffixes
  • Highlight the most important part of a domain name in the user interface
  • Accurately sort history entries by site

More complete documentation of the larger initiative can be found at publicsuffix.org

Quick Start

To use publicsuffix in an existing SBT project with Scala 2.13 or a later version, add the following dependencies to your build.sbt depending on your needs:

libraryDependencies ++= Seq(
  "io.chrisdavenport" %% "publicsuffix" % "<version>"
)

How to use

import io.chrisdavenport.publicsuffix.PublicSuffix

// On the jvm you have a global
val ps = PublicSuffix.global
// ps: PublicSuffix = io.chrisdavenport.publicsuffix.PublicSuffix$PublicSuffixFromRules@71ec2553

ps.publicSuffix("com") // tld
// res0: String = "com"
ps.publicSuffix("christopherdavenport.github.io") // registrableDomain from a hard rule
// res1: String = "github.io"
ps.publicSuffix("foo.ck") // Wildcard
// res2: String = "foo.ck"
ps.publicSuffix("www.ck") // Exception
// res3: String = "ck"
ps.publicSuffix("baz.blah.foo.r.appspot.com") // Extra domain segments
// res4: String = "foo.r.appspot.com"

A note on using it from different targets. If you are using node/jvm you can get a current version of public suffix via io.chrisdavenport.publicsuffix.retrieval.client.PublicSuffixRetrieval.getPublicSuffix if you are in the browser, you will need to use http4s-dom and then load the rules via io.chrisdavenport.publicsuffix.retrieval.Rules.retrieval.getRules(yourClient).map(PublicSuffix.fromRules)