calculateMultilocationDerivative.ts

import { ApiPromise, WsProvider } from '@polkadot/api';
import { u8aToHex } from '@polkadot/util';
import { decodeAddress } from '@polkadot/util-crypto';
import yargs from 'yargs';
import { MultiLocation } from '@polkadot/types/interfaces';

const args = yargs.options({
  'parachain-ws-provider': { type: 'string', demandOption: true, alias: 'w' }, //Target WS Provider
  address: { type: 'string', demandOption: true, alias: 'a' },
  'para-id': { type: 'string', demandOption: false, alias: 'p' }, //Origin Parachain ID,
  named: { type: 'string', demandOption: false, alias: 'n' }, // Named optional
}).argv;

// Construct
const wsProvider = new WsProvider(args['parachain-ws-provider']);

async function main() {
  // Create Provider and Type
  const api = await ApiPromise.create({
    provider: wsProvider,
    noInitWarn: true,
  });

  // Check Ethereum Address and/or Decode
  let address = args['address'];
  let account;
  const ethAddress = address.length === 42;

  // Handle name
  let named;
  if (args['named']) {
    named = { Named: args['named'] };
  } else {
    named = 'Any';
  }

  // Handle address
  if (!ethAddress) {
    address = decodeAddress(address);
    account = { AccountId32: { network: named, id: u8aToHex(address) } };
  } else {
    account = { AccountKey20: { network: named, key: address } };
  }

  // Handle para-id
  let interior;
  if (args['para-id']) {
    interior = {
      X2: [{ Parachain: JSON.parse(args['para-id']) }, account],
    };
  } else {
    interior = {
      X1: account,
    };
  }

  const multilocation: MultiLocation = api.createType(
    'XcmV1MultiLocation',
    JSON.parse(
      JSON.stringify({
        parents: 1,
        interior: interior,
      })
    )
  );

  console.log(multilocation.toString());

  const toHash = new Uint8Array([
    ...new Uint8Array([32]),
    ...new TextEncoder().encode('multiloc'),
    ...multilocation.toU8a(),
  ]);

  const DescendOriginAddress32 = u8aToHex(
    api.registry.hash(toHash).slice(0, 32)
  );
  const DescendOriginAddress20 = u8aToHex(
    api.registry.hash(toHash).slice(0, 20)
  );

  console.log('32 byte address is %s', DescendOriginAddress32);
  console.log('20 byte address is %s', DescendOriginAddress20);
}

main()
  .catch(console.error)
  .finally(() => process.exit());