CashAddress Encoding, Decoding, and Error Correction in Javascript

example.ts

import { instantiateSecp256k1, hexToBin, instantiateRipemd160, encodeCashAddress, CashAddressType, instantiateSha256, encodeCashAddressFormat, attemptCashAddressFormatErrorCorrection, decodeCashAddress, decodeCashAddressFormat, stringify } from 'bitcoin-ts';

(async () => {
  const secp256k1 = await instantiateSecp256k1();
  const sha256 = await instantiateSha256();
  const ripemd160 = await instantiateRipemd160();

  // Create an address from a private key
  const privateKey = hexToBin('f85d4bd8a03ca106c9deb47b791803dac7f0333809e3f1dd04d182e0aba6e553');
  const publicKey = secp256k1.derivePublicKeyCompressed(privateKey);
  const publicKeyHash = ripemd160.hash(sha256.hash(publicKey));

  // Encode a P2PKH CashAddress
  const cashAddress = encodeCashAddress('bchtest', CashAddressType.P2PKH, publicKeyHash);

  // Decode a CashAddress
  const cashAddressDecoded = decodeCashAddress('bchtest:qq2azmyyv6dtgczexyalqar70q036yund53jvfde0x');

  // Encode a P2PKH SLP Address (uses the CashAddress format)
  const slpAddress = encodeCashAddressFormat('slptest', 0, publicKeyHash);

  // Decode an SLP Address (uses the CashAddress format)
  const slpDecoded = decodeCashAddressFormat('slptest:qq2azmyyv6dtgczexyalqar70q036yund52xtjhwam');

  // Fix up to 2 errors in a CashAddress-formatted string
  const broken = 'bitauth:qwtcxp42fcp06phz2xec6t5krau0ftewxefy50j9xyfxwa38df40zp5xz6t5w';
  const result = attemptCashAddressFormatErrorCorrection(broken);

  // Example prompt to correct a Bitauth ID
  const pointToCorrections = (c: number[]) => Array.from({ length: c[c.length - 1] + 1 }, (_, i) => c.includes(i) ? '^' : '-').join('');
  
  console.log('Cash Address:');
  console.log(cashAddress);
  console.log(stringify(cashAddressDecoded), '\n');
  
  console.log('SLP Address:');
  console.log(slpAddress);
  console.log(stringify(slpDecoded), '\n');
  
  console.log('Error Correction:');
  console.log(result);
  console.log(typeof result === 'string' ? '[no correction]' : `
You entered:  ${broken}
              ${pointToCorrections(result.corrections)}
Did you mean: ${result.address}?`);
})();

output

Cash Address:
bchtest:qq2azmyyv6dtgczexyalqar70q036yund53jvfde0x
{
  "hash": "<Uint8Array: 0x15d16c84669ab46059313bf0747e781f1d13936d>",
  "prefix": "bchtest",
  "type": 0
} 

SLP Address:
slptest:qq2azmyyv6dtgczexyalqar70q036yund52xtjhwam
{
  "hash": "<Uint8Array: 0x15d16c84669ab46059313bf0747e781f1d13936d>",
  "prefix": "slptest",
  "version": 0
} 

Error Correction:
{
  address: 'bitauth:qwtcxp42fcp06phz2xec6t5krau0ftew5efy50j9xyfxwa38df40zp58z6t5w',
  corrections: [ 40, 63 ]
}

You entered:  bitauth:qwtcxp42fcp06phz2xec6t5krau0ftewxefy50j9xyfxwa38df40zp5xz6t5w
              ----------------------------------------^----------------------^
Did you mean: bitauth:qwtcxp42fcp06phz2xec6t5krau0ftew5efy50j9xyfxwa38df40zp58z6t5w?