Bitcoin BIP39 mnemonic seed to extended MPK (watch-only public key)

derive.js

/**
 * Converts mnemonic recovery seed
 * into xpub for watch-only services
 *
 * Dependencies:
 * npm install bitcore bitcore-mnemonic
 */

var bitcore = require('bitcore');
var bitcoreMnemonic = require('bitcore-mnemonic');

var mnemonic = '<ENTER 12-word or 24-word mnemonic seed>';

var seed = new bitcoreMnemonic(mnemonic);
var hdnode = seed.toHDPrivateKey();

// BREAD WALLET and others
// BIP32 (m/0')
var parent = hdnode.derive("m/0'");

console.log(parent.xpubkey);

// TREZOR and others
// BIP44 (m/44'/0'/0')
// var parent = hdnode.derive("m/44'/0'/0'");

// Confirm correct derivation by checking first address
// compare with first receive address generated by your app
var first = parent.derive('m/0/0').publicKey;
console.log(new bitcore.Address(first).toString());

ReferenceError: bitcoreMnemonic is not defined