anchor/ts/src/utils/token.ts

import { PublicKey } from "@solana/web3.js";

const TOKEN_PROGRAM_ID = new PublicKey(
  "TokenkegQfeZyiNwAJbNbGKPFXCWuBvf9Ss623VQ5DA"
);
const ASSOCIATED_PROGRAM_ID = new PublicKey(
  "ATokenGPvbdGVxr1b2hvZbsiqW5xWH25efTNsLJA8knL"
);

export async function associatedAddress({
  mint,
  owner,
}: {
  mint: PublicKey;
  owner: PublicKey;
}): Promise<PublicKey> {
  return (
    await PublicKey.findProgramAddress(
      [owner.toBuffer(), TOKEN_PROGRAM_ID.toBuffer(), mint.toBuffer()],
      ASSOCIATED_PROGRAM_ID
    )
  )[0];
}