ethers.js/packages/hash/src.ts/ens-normalize/lib.ts

141 lines
4.4 KiB
TypeScript

/**
* MIT License
*
* Copyright (c) 2021 Andrew Raffensperger
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all
* copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*
* This is a near carbon-copy of the original source (link below) with the
* TypeScript typings added and a few tweaks to make it ES3-compatible.
*
* See: https://github.com/adraffy/ens-normalize.js
*/
import { toUtf8CodePoints } from "@ethersproject/strings";
import { getData } from './include.js';
const r = getData();
import {read_member_array, read_mapped_map, read_emoji_trie} from './decoder.js';
// @TODO: This should be lazily loaded
const VALID = new Set(read_member_array(r));
const IGNORED = new Set(read_member_array(r));
const MAPPED = read_mapped_map(r);
const EMOJI_ROOT = read_emoji_trie(r);
//const NFC_CHECK = new Set(read_member_array(r, Array.from(VALID.values()).sort((a, b) => a - b)));
//const STOP = 0x2E;
const HYPHEN = 0x2D;
const UNDERSCORE = 0x5F;
function explode_cp(name: string): Array<number> {
return toUtf8CodePoints(name);
}
function filter_fe0f(cps: Array<number>): Array<number> {
return cps.filter(cp => cp != 0xFE0F);
}
export function ens_normalize_post_check(name: string): string {
for (let label of name.split('.')) {
let cps = explode_cp(label);
try {
for (let i = cps.lastIndexOf(UNDERSCORE) - 1; i >= 0; i--) {
if (cps[i] !== UNDERSCORE) {
throw new Error(`underscore only allowed at start`);
}
}
if (cps.length >= 4 && cps.every(cp => cp < 0x80) && cps[2] === HYPHEN && cps[3] === HYPHEN) {
throw new Error(`invalid label extension`);
}
} catch (err) {
throw new Error(`Invalid label "${label}": ${err.message}`);
}
}
return name;
}
export function ens_normalize(name: string): string {
return ens_normalize_post_check(normalize(name, filter_fe0f));
}
function normalize(name: string, emoji_filter: (a: Array<number>) => Array<number>): string {
let input = explode_cp(name).reverse(); // flip for pop
let output = [];
while (input.length) {
let emoji = consume_emoji_reversed(input);
if (emoji) {
output.push(...emoji_filter(emoji));
continue;
}
let cp = input.pop();
if (VALID.has(cp)) {
output.push(cp);
continue;
}
if (IGNORED.has(cp)) {
continue;
}
let cps = MAPPED[cp];
if (cps) {
output.push(...cps);
continue;
}
throw new Error(`Disallowed codepoint: 0x${cp.toString(16).toUpperCase()}`);
}
return ens_normalize_post_check(nfc(String.fromCodePoint(...output)));
}
function nfc(s: string): string {
return s.normalize('NFC');
}
function consume_emoji_reversed(cps: Array<number>, eaten?: Array<number>) {
let node = EMOJI_ROOT;
let emoji;
let saved;
let stack = [];
let pos = cps.length;
if (eaten) eaten.length = 0; // clear input buffer (if needed)
while (pos) {
let cp = cps[--pos];
node = node.branches.find(x => x.set.has(cp))?.node;
if (!node) break;
if (node.save) { // remember
saved = cp;
} else if (node.check) { // check exclusion
if (cp === saved) break;
}
stack.push(cp);
if (node.fe0f) {
stack.push(0xFE0F);
if (pos > 0 && cps[pos - 1] == 0xFE0F) pos--; // consume optional FE0F
}
if (node.valid) { // this is a valid emoji (so far)
emoji = stack.slice(); // copy stack
if (node.valid == 2) emoji.splice(1, 1); // delete FE0F at position 1 (RGI ZWJ don't follow spec!)
if (eaten) eaten.push(...cps.slice(pos).reverse()); // copy input (if needed)
cps.length = pos; // truncate
}
}
return emoji;
}