@adraffy/ens-normalize

What is @adraffy/ens-normalize?

@adraffy/ens-normalize is an npm package designed to normalize Ethereum Name Service (ENS) names. It ensures that ENS names are in a consistent format, which is crucial for avoiding ambiguities and ensuring compatibility across different systems.

What are @adraffy/ens-normalize's main functionalities?

Normalization

This feature allows you to normalize an ENS name to ensure it is in a consistent format. The code sample demonstrates how to normalize the ENS name 'example.eth'.

const { normalize } = require('@adraffy/ens-normalize');
const normalized = normalize('example.eth');
console.log(normalized);

Validation

This feature allows you to validate an ENS name to check if it conforms to the expected format. The code sample demonstrates how to validate the ENS name 'example.eth'.

const { validate } = require('@adraffy/ens-normalize');
const isValid = validate('example.eth');
console.log(isValid);

Unicode Handling

This feature allows you to convert Punycode-encoded ENS names to their Unicode equivalents. The code sample demonstrates how to convert the Punycode-encoded ENS name 'xn--exmple-cua.eth' to its Unicode equivalent.

const { toUnicode } = require('@adraffy/ens-normalize');
const unicodeName = toUnicode('xn--exmple-cua.eth');
console.log(unicodeName);

Other packages similar to @adraffy/ens-normalize

eth-ens-namehash

The eth-ens-namehash package is another tool for generating ENS namehashes. It includes some basic normalization features but is primarily focused on the namehashing process. It is less comprehensive in normalization compared to @adraffy/ens-normalize.

punycode

The punycode package provides utilities for converting between Unicode and Punycode, which is useful for handling internationalized domain names (IDNs). While it does not specifically target ENS names, it can be used in conjunction with other packages to handle Unicode normalization.

README

ens-normalize.js

0-dependency Ethereum Name Service (ENS) Name Normalizer.

npm i @adraffy/ens-normalize ✓

• 🏛️ Follows ENSIP-15: ENS Name Normalization Standard
  • Unicode: 16.0.0 • CLDR: 45
  • Other implementations:
    • Python — namehash/ens-normalize-python
    • C# — adraffy/ENSNormalize.cs
    • Java — adraffy/ENSNormalize.java
    • Go — adraffy/go-ens-normalize
    • Javascript — ensdomains/eth-ens-namehash
  • Breakdown Reports from ENSIP-1
• ✅️ Passes 100% ENSIP-15 Validation Tests
• ✅️ Passes 100% Unicode Normalization Tests
• Minified File Sizes:
  • 29KB — native NFC via nf-native.js using String.normalize() ⚠️
  • 38KB Default — custom NFC via nf.js
  • 44KB Everything! — custom NFC + sub-libraries: parts.js, utils.js
• Included Apps:
  • Resolver Demo ⭐
  • Supported Emoji
  • Character Viewer
  • Confused Explainer
• Related Projects:
  • Recent .eth Registrations • .eth Renews
  • .eth Expirations
  • Emoji Frequency Explorer
  • Label Database • Labelhash⁻¹
  • adraffy/punycode.js • Punycode Coder
  • adraffy/keccak.js • Keccak Hasher
  • adraffy/emoji.js • Emoji Parser
  • More links at bottom of Resolver Demo

import {ens_normalize} from '@adraffy/ens-normalize'; // or require()
// browser: https://cdn.jsdelivr.net/npm/@adraffy/ens-normalize@latest/dist/index.min.mjs (or .cjs)

// *** ALL errors thrown by this library are safe to print ***
// - characters are shown as {HEX} if should_escape()
// - potentially different bidi directions inside "quotes"
// - 200E is used near "quotes" to prevent spillover
// - an "error type" can be extracted by slicing up to the first (:)
// - labels are middle-truncated with ellipsis (…) at 63 cps

// string -> string
// throws on invalid names
// output ready for namehash
let normalized = ens_normalize('RaFFY🚴‍♂️.eTh');
// => "raffy🚴‍♂.eth"

// note: does not enforce .eth registrar 3-character minimum

Format names with fully-qualified emoji:

// works like ens_normalize()
// output ready for display
let pretty = ens_beautify('1⃣2⃣.eth'); 
// => "1️⃣2️⃣.eth"

// note: normalization is unchanged:
// ens_normalize(ens_beautify(x)) == ens_normalize(x)

Normalize name fragments for substring search:

// these fragments fail ens_normalize() 
// but will normalize fine as fragments
let frag1 = ens_normalize_fragment('AB--');    // expected error: label ext
let frag2 = ens_normalize_fragment('\u{303}'); // expected error: leading cm
let frag3 = ens_normalize_fragment('οо');      // expected error: mixture

Input-based tokenization:

// string -> Token[]
// never throws
let tokens = ens_tokenize('_R💩\u{FE0F}a\u{FE0F}\u{304}\u{AD}./');
// [
//     { type: 'valid', cp: [ 95 ] }, // valid (as-is)
//     {
//         type: 'mapped', 
//         cp: 82,         // input
//         cps: [ 114 ]    // output
//     }, 
//     { 
//         type: 'emoji',
//         input: Emoji(2) [ 128169, 65039 ],  // input 
//         emoji: [ 128169, 65039 ],           // fully-qualified
//         cps: Emoji(1) [ 128169 ]            // output (normalized)
//     },
//     {
//         type: 'nfc',
//         input: [ 97, 772 ],  // input  (before nfc)
//         tokens0: [           // tokens (before nfc)
//             { type: 'valid', cps: [ 97 ] },
//             { type: 'ignored', cp: 65039 },
//             { type: 'valid', cps: [ 772 ] }
//         ],
//         cps: [ 257 ],        // output (after nfc)
//         tokens: [            // tokens (after nfc)
//             { type: 'valid', cps: [ 257 ] }
//         ]
//     },
//     { type: 'ignored', cp: 173 },
//     { type: 'stop', cp: 46 },
//     { type: 'disallowed', cp: 47 }
// ]

// note: if name is normalizable, then:
// ens_normalize(ens_tokenize(name).map(token => {
//     ** convert valid/mapped/nfc/stop to string **
// }).join('')) == ens_normalize(name)

Output-based tokenization:

// string -> Label[]
// never throws
let labels = ens_split('💩Raffy.eth_');
// [
//   {
//     input: [ 128169, 82, 97, 102, 102, 121 ],  
//     offset: 0, // index of codepoint, not substring index!
//                // (corresponding length can be inferred from input)
//     tokens: [
//       Emoji(2) [ 128169, 65039 ],   // emoji
//       [ 114, 97, 102, 102, 121 ]    // nfc-text
//     ],
//     output: [ 128169, 114, 97, 102, 102, 121 ],
//     emoji: true,
//     type: 'Latin'
//   },
//   {
//     input: [ 101, 116, 104, 95 ],
//     offset: 7,
//     tokens: [ [ 101, 116, 104, 95 ] ],
//     output: [ 101, 116, 104, 95 ],
//     error: Error('underscore allowed only at start')
//   }
// ]

Generate a sorted array of (beautified) supported emoji codepoints:

// () -> number[][]
let emojis = ens_emoji();
// [
//     [ 2764 ],
//     [ 128169, 65039 ],
//     [ 128105, 127997, 8205, 9877, 65039 ],
//     ...
// ]

Determine if a character shouldn't be printed directly:

// number -> bool
should_escape(0x202E); // eg. RIGHT-TO-LEFT OVERRIDE => true

Determine if a character is a combining mark:

// number -> bool
is_combining_mark(0x20E3); // eg. COMBINING ENCLOSING KEYCAP => true

Format codepoints as print-safe string:

// number[] -> string
safe_str_from_cps([0x300, 0, 32, 97]); // "◌̀{00} a"
safe_str_from_cps(Array(100).fill(97), 4); // "aa…aa" => middle-truncated

Build

• git clone this repo, then npm install
• Follow instructions in /derive/ to generate data files
  • npm run derive
    • spec.json
    • nf.json
    • nf-tests.json
• npm run make — compress data files from /derive/output/
  • include-ens.js
  • include-nf.js
  • include-versions.js
• Follow instructions in /validate/ to generate validation tests
  • npm run validate
    • tests.json
• npm run test — perform validation tests
• npm run build — create /dist/
• npm run rebuild — run all the commands above
• npm run order — create optimal group ordering and rebuild again

Security

• Build and compare against include-versions.js
  • spec_hash — SHA-256 of spec.json bytes
  • ens_hash_base64 — SHA-256 of include-ens.js base64 literal
  • nf_hash_base64 — SHA-256 of include-nf.js base64 literal