solana-program-examples/tokens/escrow/anchor/tests/escrow.ts

import { randomBytes } from 'node:crypto';
import * as anchor from '@coral-xyz/anchor';
import { BN, type Program } from '@coral-xyz/anchor';
import {
  MINT_SIZE,
  TOKEN_2022_PROGRAM_ID,
  type TOKEN_PROGRAM_ID,
  createAssociatedTokenAccountIdempotentInstruction,
  createInitializeMint2Instruction,
  createMintToInstruction,
  getAssociatedTokenAddressSync,
  getMinimumBalanceForRentExemptMint,
} from '@solana/spl-token';
import { LAMPORTS_PER_SOL, PublicKey, SystemProgram, Transaction, type TransactionInstruction } from '@solana/web3.js';
import { assert } from 'chai';
import type { Escrow } from '../target/types/escrow';

import { confirmTransaction, makeKeypairs } from '@solana-developers/helpers';

const TOKEN_PROGRAM: typeof TOKEN_2022_PROGRAM_ID | typeof TOKEN_PROGRAM_ID = TOKEN_2022_PROGRAM_ID;

const getRandomBigNumber = (size = 8) => {
  return new BN(randomBytes(size));
};

describe('escrow', async () => {
  anchor.setProvider(anchor.AnchorProvider.env());

  const provider = anchor.getProvider();

  const connection = provider.connection;

  const program = anchor.workspace.Escrow as Program<Escrow>;

  // We're going to reuse these accounts across multiple tests
  const accounts: Record<string, PublicKey> = {
    tokenProgram: TOKEN_PROGRAM,
  };

  const [alice, bob, tokenMintA, tokenMintB] = makeKeypairs(4);

  before('Creates Alice and Bob accounts, 2 token mints, and associated token accounts for both tokens for both users', async () => {
    const [aliceTokenAccountA, aliceTokenAccountB, bobTokenAccountA, bobTokenAccountB] = [alice, bob].flatMap((keypair) =>
      [tokenMintA, tokenMintB].map((mint) => getAssociatedTokenAddressSync(mint.publicKey, keypair.publicKey, false, TOKEN_PROGRAM)),
    );

    // Airdrops to users, and creates two tokens mints 'A' and 'B'"
    const minimumLamports = await getMinimumBalanceForRentExemptMint(connection);

    const sendSolInstructions: Array<TransactionInstruction> = [alice, bob].map((account) =>
      SystemProgram.transfer({
        fromPubkey: provider.publicKey,
        toPubkey: account.publicKey,
        lamports: 10 * LAMPORTS_PER_SOL,
      }),
    );

    const createMintInstructions: Array<TransactionInstruction> = [tokenMintA, tokenMintB].map((mint) =>
      SystemProgram.createAccount({
        fromPubkey: provider.publicKey,
        newAccountPubkey: mint.publicKey,
        lamports: minimumLamports,
        space: MINT_SIZE,
        programId: TOKEN_PROGRAM,
      }),
    );

    // Make tokenA and tokenB mints, mint tokens and create ATAs
    const mintTokensInstructions: Array<TransactionInstruction> = [
      {
        mint: tokenMintA.publicKey,
        authority: alice.publicKey,
        ata: aliceTokenAccountA,
      },
      {
        mint: tokenMintB.publicKey,
        authority: bob.publicKey,
        ata: bobTokenAccountB,
      },
    ].flatMap((mintDetails) => [
      createInitializeMint2Instruction(mintDetails.mint, 6, mintDetails.authority, null, TOKEN_PROGRAM),
      createAssociatedTokenAccountIdempotentInstruction(provider.publicKey, mintDetails.ata, mintDetails.authority, mintDetails.mint, TOKEN_PROGRAM),
      createMintToInstruction(mintDetails.mint, mintDetails.ata, mintDetails.authority, 1_000_000_000, [], TOKEN_PROGRAM),
    ]);

    // Add all these instructions to our transaction
    const tx = new Transaction();
    tx.instructions = [...sendSolInstructions, ...createMintInstructions, ...mintTokensInstructions];

    const transactionSignature = await provider.sendAndConfirm(tx, [tokenMintA, tokenMintB, alice, bob]);

    // Save the accounts for later use
    accounts.maker = alice.publicKey;
    accounts.taker = bob.publicKey;
    accounts.tokenMintA = tokenMintA.publicKey;
    accounts.makerTokenAccountA = aliceTokenAccountA;
    accounts.takerTokenAccountA = bobTokenAccountA;
    accounts.tokenMintB = tokenMintB.publicKey;
    accounts.makerTokenAccountB = aliceTokenAccountB;
    accounts.takerTokenAccountB = bobTokenAccountB;
  });

  const tokenAOfferedAmount = new BN(1_000_000);
  const tokenBWantedAmount = new BN(1_000_000);

  // We'll call this function from multiple tests, so let's seperate it out
  const make = async () => {
    // Pick a random ID for the offer we'll make
    const offerId = getRandomBigNumber();

    // Then determine the account addresses we'll use for the offer and the vault
    const offer = PublicKey.findProgramAddressSync(
      [Buffer.from('offer'), accounts.maker.toBuffer(), offerId.toArrayLike(Buffer, 'le', 8)],
      program.programId,
    )[0];

    const vault = getAssociatedTokenAddressSync(accounts.tokenMintA, offer, true, TOKEN_PROGRAM);

    accounts.offer = offer;
    accounts.vault = vault;

    const transactionSignature = await program.methods
      .makeOffer(offerId, tokenAOfferedAmount, tokenBWantedAmount)
      .accounts({ ...accounts })
      .signers([alice])
      .rpc();

    await confirmTransaction(connection, transactionSignature);

    // Check our vault contains the tokens offered
    const vaultBalanceResponse = await connection.getTokenAccountBalance(vault);
    const vaultBalance = new BN(vaultBalanceResponse.value.amount);
    assert(vaultBalance.eq(tokenAOfferedAmount));

    // Check our Offer account contains the correct data
    const offerAccount = await program.account.offer.fetch(offer);

    assert(offerAccount.maker.equals(alice.publicKey));
    assert(offerAccount.tokenMintA.equals(accounts.tokenMintA));
    assert(offerAccount.tokenMintB.equals(accounts.tokenMintB));
    assert(offerAccount.tokenBWantedAmount.eq(tokenBWantedAmount));
  };

  // We'll call this function from multiple tests, so let's seperate it out
  const take = async () => {
    const transactionSignature = await program.methods
      .takeOffer()
      .accounts({ ...accounts })
      .signers([bob])
      .rpc();

    await confirmTransaction(connection, transactionSignature);

    // Check the offered tokens are now in Bob's account
    // (note: there is no before balance as Bob didn't have any offered tokens before the transaction)
    const bobTokenAccountBalanceAfterResponse = await connection.getTokenAccountBalance(accounts.takerTokenAccountA);
    const bobTokenAccountBalanceAfter = new BN(bobTokenAccountBalanceAfterResponse.value.amount);
    assert(bobTokenAccountBalanceAfter.eq(tokenAOfferedAmount));

    // Check the wanted tokens are now in Alice's account
    // (note: there is no before balance as Alice didn't have any wanted tokens before the transaction)
    const aliceTokenAccountBalanceAfterResponse = await connection.getTokenAccountBalance(accounts.makerTokenAccountB);
    const aliceTokenAccountBalanceAfter = new BN(aliceTokenAccountBalanceAfterResponse.value.amount);
    assert(aliceTokenAccountBalanceAfter.eq(tokenBWantedAmount));
  };

  it('Puts the tokens Alice offers into the vault when Alice makes an offer', async () => {
    await make();
  });

  it("Puts the tokens from the vault into Bob's account, and gives Alice Bob's tokens, when Bob takes an offer", async () => {
    await take();
  });
});