Content

Clarity of Mind Foreword Introduction

Unit tests

The tiny-market contract is more sizeable than what we have built before. We will make an effort to structure the unit tests to avoid repetition. Common actions are turned into helper functions so that we can call them when needed. These include:

  • Turning an Account and contract name into a contract principal string.
  • Minting a new token for testing, both for NFTs and payment assets.
  • Asserting that an NFT token transfer has happened. (Clarinet does not support this yet.)
  • Creating an order tuple.
  • Creating a transaction for common actions like whitelisting an asset contract or listing an NFT.

Token minting helpers

To prevent hard-coding contract names in our tests, we define a constant for each. The helper functions will construct the contract call to the mint function and mine a block to include it. The chain and deployer parameters will be passed in by the tests themselves. The functions then return some helpful information like the NFT asset contract principal, the token ID or amount, and the block data itself.

const contractName = 'tiny-market';

const defaultNftAssetContract = 'sip009-nft';
const defaultPaymentAssetContract = 'sip010-token';

const contractPrincipal = (deployer: Account) => `${deployer.address}.${contractName}`;

function mintNft({ chain, deployer, recipient, nftAssetContract = defaultNftAssetContract }: { chain: Chain, deployer: Account, recipient: Account, nftAssetContract?: string }) {
    const block = chain.mineBlock([
        Tx.contractCall(nftAssetContract, 'mint', [types.principal(recipient.address)], deployer.address),
    ]);
    block.receipts[0].result.expectOk();
    const nftMintEvent = block.receipts[0].events[0].nft_mint_event;
    const [nftAssetContractPrincipal, nftAssetId] = nftMintEvent.asset_identifier.split('::');
    return { nftAssetContract: nftAssetContractPrincipal, nftAssetId, tokenId: nftMintEvent.value.substr(1), block };
}

function mintFt({ chain, deployer, amount, recipient, paymentAssetContract = defaultPaymentAssetContract }: { chain: Chain, deployer: Account, amount: number, recipient: Account, paymentAssetContract?: string }) {
    const block = chain.mineBlock([
        Tx.contractCall(paymentAssetContract, 'mint', [types.uint(amount), types.principal(recipient.address)], deployer.address),
    ]);
    block.receipts[0].result.expectOk();
    const ftMintEvent = block.receipts[0].events[0].ft_mint_event;
    const [paymentAssetContractPrincipal, paymentAssetId] = ftMintEvent.asset_identifier.split('::');
    return { paymentAssetContract: paymentAssetContractPrincipal, paymentAssetId, block };
}

Asserting NFT transfers

NFT transfer events are emitted by Clarinet but no function exists to assert their existence. We therefore make our own and define a basic interface that describes the transfer event. It will check that an event with the expected properties exists: the right NFT asset contract, token ID, and principal.

interface Sip009NftTransferEvent {
    type: string,
    nft_transfer_event: {
        asset_identifier: string,
        sender: string,
        recipient: string,
        value: string
    }
}

function assertNftTransfer(event: Sip009NftTransferEvent, nftAssetContract: string, tokenId: number, sender: string, recipient: string) {
    assertEquals(typeof event, 'object');
    assertEquals(event.type, 'nft_transfer_event');
    assertEquals(event.nft_transfer_event.asset_identifier.substr(0, nftAssetContract.length), nftAssetContract);
    event.nft_transfer_event.sender.expectPrincipal(sender);
    event.nft_transfer_event.recipient.expectPrincipal(recipient);
    event.nft_transfer_event.value.expectUint(tokenId);
}

Order tuple helper

Since listing assets by calling into list-asset is something that we will do quite often, we will also create a helper function that constructs the net-asset order tuple. The function takes an object with properties equal to that of the tuple, just camel-cased instead of with dashes.

interface Order {
    taker?: string,
    tokenId: number,
    expiry: number,
    price: number,
    paymentAssetContract?: string
}

const makeOrder = (order: Order) =>
    types.tuple({
        'taker': order.taker ? types.some(types.principal(order.taker)) : types.none(),
        'token-id': types.uint(order.tokenId),
        'expiry': types.uint(order.expiry),
        'price': types.uint(order.price),
        'payment-asset-contract': order.paymentAssetContract ? types.some(types.principal(order.paymentAssetContract)) : types.none(),
    });

Whitelisting transaction

The helper to create a whitelisting transaction is a one-liner. It takes the asset contract to whitelist and whether it should be whitelisted, finally the the contract owner that should send the transaction, as it is a guarded function.

const whitelistAssetTx = (assetContract: string, whitelisted: boolean, contractOwner: Account) =>
    Tx.contractCall(contractName, 'set-whitelisted', [types.principal(assetContract), types.bool(whitelisted)], contractOwner.address);

Listing an NFT

Listing a new order is likewise a one-liner. We will also make it so that you can pass in both an Order object or an order tuple (which is represented as a string by Clarinet). If an Order is passed, all we have to do is call the makeOrder helper.

const listOrderTx = (nftAssetContract: string, maker: Account, order: Order | string) =>
    Tx.contractCall(contractName, 'list-asset', [types.principal(nftAssetContract), typeof order === 'string' ? order : makeOrder(order)], maker.address);

Listing tests

We can then use the helpers to construct our first tests: listing an NFT for sale for STX and for SIP010 fungible tokens.

Clarinet.test({
    name: "Can list an NFT for sale for STX",
    async fn(chain: Chain, accounts: Map<string, Account>) {
        const [deployer, maker] = ['deployer', 'wallet_1'].map(name => accounts.get(name)!);
        const { nftAssetContract, tokenId } = mintNft({ chain, deployer, recipient: maker });
        const order: Order = { tokenId, expiry: 10, price: 10 };
        const block = chain.mineBlock([
            whitelistAssetTx(nftAssetContract, true, deployer),
            listOrderTx(nftAssetContract, maker, order)
        ]);
        block.receipts[1].result.expectOk().expectUint(0);
        assertNftTransfer(block.receipts[1].events[0], nftAssetContract, tokenId, maker.address, contractPrincipal(deployer));
    }
});

Clarinet.test({
    name: "Can list an NFT for sale for any SIP010 fungible token",
    async fn(chain: Chain, accounts: Map<string, Account>) {
        const [deployer, maker] = ['deployer', 'wallet_1'].map(name => accounts.get(name)!);
        const { nftAssetContract, tokenId } = mintNft({ chain, deployer, recipient: maker });
        const { paymentAssetContract } = mintFt({ chain, deployer, recipient: maker, amount: 1 });
        const order: Order = { tokenId, expiry: 10, price: 10, paymentAssetContract };
        const block = chain.mineBlock([
            whitelistAssetTx(nftAssetContract, true, deployer),
            whitelistAssetTx(paymentAssetContract, true, deployer),
            listOrderTx(nftAssetContract, maker, order)
        ]);
        block.receipts[2].result.expectOk().expectUint(0);
        assertNftTransfer(block.receipts[2].events[0], nftAssetContract, tokenId, maker.address, contractPrincipal(deployer));
    }
});

Invalid listings

A listing call should fail under the following circumstances:

  • The expiry block height of the order is in the past.
  • The NFT is being listed for nothing. (A price of zero.)
  • Someone is trying to list an NFT for sale that the sender does not own.
Clarinet.test({
    name: "Cannot list an NFT for sale if the expiry is in the past",
    async fn(chain: Chain, accounts: Map<string, Account>) {
        const [deployer, maker] = ['deployer', 'wallet_1'].map(name => accounts.get(name)!);
        const { nftAssetContract, tokenId } = mintNft({ chain, deployer, recipient: maker });
        const expiry = 10;
        const order: Order = { tokenId, expiry, price: 10 };
        chain.mineEmptyBlockUntil(expiry + 1);
        const block = chain.mineBlock([
            whitelistAssetTx(nftAssetContract, true, deployer),
            listOrderTx(nftAssetContract, maker, order)
        ]);
        block.receipts[1].result.expectErr().expectUint(1000);
        assertEquals(block.receipts[1].events.length, 0);
    }
});

Clarinet.test({
    name: "Cannot list an NFT for sale for nothing",
    async fn(chain: Chain, accounts: Map<string, Account>) {
        const [deployer, maker] = ['deployer', 'wallet_1'].map(name => accounts.get(name)!);
        const { nftAssetContract, tokenId } = mintNft({ chain, deployer, recipient: maker });
        const order: Order = { tokenId, expiry: 10, price: 0 };
        const block = chain.mineBlock([
            whitelistAssetTx(nftAssetContract, true, deployer),
            listOrderTx(nftAssetContract, maker, order)
        ]);
        block.receipts[1].result.expectErr().expectUint(1001);
        assertEquals(block.receipts[1].events.length, 0);
    }
});

Clarinet.test({
    name: "Cannot list an NFT for sale that the sender does not own",
    async fn(chain: Chain, accounts: Map<string, Account>) {
        const [deployer, maker, taker] = ['deployer', 'wallet_1', 'wallet_2'].map(name => accounts.get(name)!);
        const { nftAssetContract, tokenId } = mintNft({ chain, deployer, recipient: taker });
        const order: Order = { tokenId, expiry: 10, price: 10 };
        const block = chain.mineBlock([
            whitelistAssetTx(nftAssetContract, true, deployer),
            listOrderTx(nftAssetContract, maker, order)
        ]);
        block.receipts[1].result.expectErr().expectUint(1);
        assertEquals(block.receipts[1].events.length, 0);
    }
});

Cancelling listings

Only the maker can cancel an active listing, we will cover this with two tests.

Clarinet.test({
    name: "Maker can cancel a listing",
    async fn(chain: Chain, accounts: Map<string, Account>) {
        const [deployer, maker] = ['deployer', 'wallet_1'].map(name => accounts.get(name)!);
        const { nftAssetContract, tokenId } = mintNft({ chain, deployer, recipient: maker });
        const order: Order = { tokenId, expiry: 10, price: 10 };
        const block = chain.mineBlock([
            whitelistAssetTx(nftAssetContract, true, deployer),
            listOrderTx(nftAssetContract, maker, order),
            Tx.contractCall(contractName, 'cancel-listing', [types.uint(0), types.principal(nftAssetContract)], maker.address)
        ]);
        block.receipts[2].result.expectOk().expectBool(true);
        assertNftTransfer(block.receipts[2].events[0], nftAssetContract, tokenId, contractPrincipal(deployer), maker.address);
    }
});

Clarinet.test({
    name: "Non-maker cannot cancel listing",
    async fn(chain: Chain, accounts: Map<string, Account>) {
        const [deployer, maker, otherAccount] = ['deployer', 'wallet_1', 'wallet_2'].map(name => accounts.get(name)!);
        const { nftAssetContract, tokenId } = mintNft({ chain, deployer, recipient: maker });
        const order: Order = { tokenId, expiry: 10, price: 10 };
        const block = chain.mineBlock([
            whitelistAssetTx(nftAssetContract, true, deployer),
            listOrderTx(nftAssetContract, maker, order),
            Tx.contractCall(contractName, 'cancel-listing', [types.uint(0), types.principal(nftAssetContract)], otherAccount.address)
        ]);
        block.receipts[2].result.expectErr().expectUint(2001);
        assertEquals(block.receipts[2].events.length, 0);
    }
});

Retrieving listings

Listings can be retrieved until they are cancelled. We will add a test that retrieves an active listing and make sure that the returned tuple contains the information we expect. The next test verifies that retrieving a listing that is cancelled or does not exist returns none.

Clarinet.test({
    name: "Can get listings that have not been cancelled",
    async fn(chain: Chain, accounts: Map<string, Account>) {
        const [deployer, maker] = ['deployer', 'wallet_1'].map(name => accounts.get(name)!);
        const { nftAssetContract, tokenId } = mintNft({ chain, deployer, recipient: maker });
        const order: Order = { tokenId, expiry: 10, price: 10 };
        const block = chain.mineBlock([
            whitelistAssetTx(nftAssetContract, true, deployer),
            listOrderTx(nftAssetContract, maker, order)
        ]);
        const listingIdUint = block.receipts[1].result.expectOk();
        const receipt = chain.callReadOnlyFn(contractName, 'get-listing', [listingIdUint], deployer.address);
        const listing: { [key: string]: string } = receipt.result.expectSome().expectTuple() as any;

        listing['expiry'].expectUint(order.expiry);
        listing['maker'].expectPrincipal(maker.address);
        listing['payment-asset-contract'].expectNone();
        listing['price'].expectUint(order.price);
        listing['taker'].expectNone();
        listing['nft-asset-contract'].expectPrincipal(nftAssetContract);
        listing['token-id'].expectUint(tokenId);
    }
});

Clarinet.test({
    name: "Cannot get listings that have been cancelled or do not exist",
    async fn(chain: Chain, accounts: Map<string, Account>) {
        const [deployer, maker] = ['deployer', 'wallet_1'].map(name => accounts.get(name)!);
        const { nftAssetContract, tokenId } = mintNft({ chain, deployer, recipient: maker });
        const order: Order = { tokenId, expiry: 10, price: 10 };
        chain.mineBlock([
            listOrderTx(nftAssetContract, maker, order),
            Tx.contractCall(contractName, 'cancel-listing', [types.uint(0), types.principal(nftAssetContract)], maker.address)
        ]);
        const receipts = [types.uint(0), types.uint(999)].map(listingId => chain.callReadOnlyFn(contractName, 'get-listing', [listingId], deployer.address));
        receipts.map(receipt => receipt.result.expectNone());
    }
});

Fulfilling listings

And here are the ones we have been waiting for: the tests for order fulfilment. Since a seller can list an NFT for sale for either STX or SIP010 tokens, we write a separate test for both.

Clarinet.test({
    name: "Can fulfil an active listing with STX",
    async fn(chain: Chain, accounts: Map<string, Account>) {
        const [deployer, maker, taker] = ['deployer', 'wallet_1', 'wallet_2'].map(name => accounts.get(name)!);
        const { nftAssetContract, tokenId } = mintNft({ chain, deployer, recipient: maker });
        const order: Order = { tokenId, expiry: 10, price: 10 };
        const block = chain.mineBlock([
            whitelistAssetTx(nftAssetContract, true, deployer),
            listOrderTx(nftAssetContract, maker, order),
            Tx.contractCall(contractName, 'fulfil-listing-stx', [types.uint(0), types.principal(nftAssetContract)], taker.address)
        ]);
        block.receipts[2].result.expectOk().expectUint(0);
        assertNftTransfer(block.receipts[2].events[0], nftAssetContract, tokenId, contractPrincipal(deployer), taker.address);
        block.receipts[2].events.expectSTXTransferEvent(order.price, taker.address, maker.address);
    }
});

Clarinet.test({
    name: "Can fulfil an active listing with SIP010 fungible tokens",
    async fn(chain: Chain, accounts: Map<string, Account>) {
        const [deployer, maker, taker] = ['deployer', 'wallet_1', 'wallet_2'].map(name => accounts.get(name)!);
        const price = 50;
        const { nftAssetContract, tokenId } = mintNft({ chain, deployer, recipient: maker });
        const { paymentAssetContract, paymentAssetId } = mintFt({ chain, deployer, recipient: taker, amount: price });
        const order: Order = { tokenId, expiry: 10, price, paymentAssetContract };
        const block = chain.mineBlock([
            whitelistAssetTx(nftAssetContract, true, deployer),
            whitelistAssetTx(paymentAssetContract, true, deployer),
            listOrderTx(nftAssetContract, maker, order),
            Tx.contractCall(contractName, 'fulfil-listing-ft', [types.uint(0), types.principal(nftAssetContract), types.principal(paymentAssetContract)], taker.address)
        ]);
        block.receipts[3].result.expectOk().expectUint(0);
        assertNftTransfer(block.receipts[3].events[0], nftAssetContract, tokenId, contractPrincipal(deployer), taker.address);
        block.receipts[3].events.expectFungibleTokenTransferEvent(price, taker.address, maker.address, paymentAssetId);
    }
});

Basic fulfilment errors

There are some basic situations in which fulfilment fails, these are:

  • The seller is trying to buy its own NFT,
  • A buyer is trying to fulfil a listing that does not exist; and,
  • A buyer is trying to fulfil a listing that has expired.
Clarinet.test({
    name: "Cannot fulfil own listing",
    async fn(chain: Chain, accounts: Map<string, Account>) {
        const [deployer, maker] = ['deployer', 'wallet_1'].map(name => accounts.get(name)!);
        const { nftAssetContract, tokenId } = mintNft({ chain, deployer, recipient: maker });
        const order: Order = { tokenId, expiry: 10, price: 10 };
        const block = chain.mineBlock([
            whitelistAssetTx(nftAssetContract, true, deployer),
            listOrderTx(nftAssetContract, maker, order),
            Tx.contractCall(contractName, 'fulfil-listing-stx', [types.uint(0), types.principal(nftAssetContract)], maker.address)
        ]);
        block.receipts[2].result.expectErr().expectUint(2005);
        assertEquals(block.receipts[2].events.length, 0);
    }
});

Clarinet.test({
    name: "Cannot fulfil an unknown listing",
    async fn(chain: Chain, accounts: Map<string, Account>) {
        const [deployer, maker, taker] = ['deployer', 'wallet_1', 'wallet_2'].map(name => accounts.get(name)!);
        const { nftAssetContract } = mintNft({ chain, deployer, recipient: maker });
        const block = chain.mineBlock([
            whitelistAssetTx(nftAssetContract, true, deployer),
            Tx.contractCall(contractName, 'fulfil-listing-stx', [types.uint(0), types.principal(nftAssetContract)], taker.address)
        ])
        block.receipts[1].result.expectErr().expectUint(2000);
        assertEquals(block.receipts[1].events.length, 0);
    }
});

Clarinet.test({
    name: "Cannot fulfil an expired listing",
    async fn(chain: Chain, accounts: Map<string, Account>) {
        const [deployer, maker, taker] = ['deployer', 'wallet_1', 'wallet_2'].map(name => accounts.get(name)!);
        const expiry = 10;
        const { nftAssetContract, tokenId } = mintNft({ chain, deployer, recipient: maker });
        const order: Order = { tokenId, expiry, price: 10 };
        chain.mineBlock([
            whitelistAssetTx(nftAssetContract, true, deployer),
            listOrderTx(nftAssetContract, maker, order),
        ]);
        chain.mineEmptyBlockUntil(expiry + 1);
        const block = chain.mineBlock([
            Tx.contractCall(contractName, 'fulfil-listing-stx', [types.uint(0), types.principal(nftAssetContract)], taker.address)
        ])
        block.receipts[0].result.expectErr().expectUint(2002);
        assertEquals(block.receipts[0].events.length, 0);
    }
});

Wrong payment asset or trait reference

We now add tests that confirm that a listing cannot be fulfilled with the wrong payment asset. We test both STX and SIP010 tokens, as well as the situation where the transaction sender passes in the wrong asset trait reference.

Since we have to test our listings against different assets we need to instantiate a bogus NFT and payment asset contract. We could copy and paste our test asset contracts but that seems tedious. Clarinet actually allows you to instantiate the same contract file under a different name. Open Clarinet.toml and add an entry for our bogus-nft by coping the entry for sip009-nf.

[contracts.sip009-nft]
path = "contracts/sip009-nft.clar"
depends_on = ["sip009-nft-trait"]

[contracts.bogus-nft]
path = "contracts/sip009-nft.clar"
depends_on = ["sip009-nft-trait"]

Then we do the same for the payment asset. We will call the new entry bogus-ft.

[contracts.sip010-token]
path = "contracts/sip010-token.clar"
depends_on = ["sip010-ft-trait"]

[contracts.bogus-ft]
path = "contracts/sip010-token.clar"
depends_on = ["sip010-ft-trait"]

From this point on, sip009-nft.clar and sip010-token.clar will be instantiated twice under different names. Quite useful for our tests.

Clarinet.test({
    name: "Cannot fulfil a listing with a different NFT contract reference",
    async fn(chain: Chain, accounts: Map<string, Account>) {
        const [deployer, maker, taker] = ['deployer', 'wallet_1', 'wallet_2'].map(name => accounts.get(name)!);
        const expiry = 10;
        const { nftAssetContract, tokenId } = mintNft({ chain, deployer, recipient: maker });
        const order: Order = { tokenId, expiry: 10, price: 10 };
        const bogusNftAssetContract = `${deployer.address}.bogus-nft`;
        const block = chain.mineBlock([
            whitelistAssetTx(nftAssetContract, true, deployer),
            listOrderTx(nftAssetContract, maker, order),
            Tx.contractCall(contractName, 'fulfil-listing-stx', [types.uint(0), types.principal(bogusNftAssetContract)], taker.address)
        ]);
        block.receipts[2].result.expectErr().expectUint(2003);
        assertEquals(block.receipts[2].events.length, 0);
    }
});

Clarinet.test({
    name: "Cannot fulfil an active STX listing with SIP010 fungible tokens",
    async fn(chain: Chain, accounts: Map<string, Account>) {
        const [deployer, maker, taker] = ['deployer', 'wallet_1', 'wallet_2'].map(name => accounts.get(name)!);
        const price = 50;
        const { nftAssetContract, tokenId } = mintNft({ chain, deployer, recipient: maker });
        const { paymentAssetContract } = mintFt({ chain, deployer, recipient: taker, amount: price });
        const order: Order = { tokenId, expiry: 10, price };
        const block = chain.mineBlock([
            whitelistAssetTx(nftAssetContract, true, deployer),
            whitelistAssetTx(paymentAssetContract, true, deployer),
            listOrderTx(nftAssetContract, maker, order),
            Tx.contractCall(contractName, 'fulfil-listing-ft', [types.uint(0), types.principal(nftAssetContract), types.principal(paymentAssetContract)], taker.address)
        ]);
        block.receipts[3].result.expectErr().expectUint(2004);
        assertEquals(block.receipts[3].events.length, 0);
    }
});

Clarinet.test({
    name: "Cannot fulfil an active SIP010 fungible token listing with STX",
    async fn(chain: Chain, accounts: Map<string, Account>) {
        const [deployer, maker, taker] = ['deployer', 'wallet_1', 'wallet_2'].map(name => accounts.get(name)!);
        const price = 50;
        const { nftAssetContract, tokenId } = mintNft({ chain, deployer, recipient: maker });
        const { paymentAssetContract } = mintFt({ chain, deployer, recipient: taker, amount: price });
        const order: Order = { tokenId, expiry: 10, price, paymentAssetContract };
        const block = chain.mineBlock([
            whitelistAssetTx(nftAssetContract, true, deployer),
            whitelistAssetTx(paymentAssetContract, true, deployer),
            listOrderTx(nftAssetContract, maker, order),
            Tx.contractCall(contractName, 'fulfil-listing-stx', [types.uint(0), types.principal(nftAssetContract)], taker.address)
        ]);
        block.receipts[3].result.expectErr().expectUint(2004);
        assertEquals(block.receipts[3].events.length, 0);
    }
});

Clarinet.test({
    name: "Cannot fulfil an active SIP010 fungible token listing with a different SIP010 fungible token contract reference",
    async fn(chain: Chain, accounts: Map<string, Account>) {
        const [deployer, maker, taker] = ['deployer', 'wallet_1', 'wallet_2'].map(name => accounts.get(name)!);
        const price = 50;
        const { nftAssetContract, tokenId } = mintNft({ chain, deployer, recipient: maker });
        const { paymentAssetContract } = mintFt({ chain, deployer, recipient: taker, amount: price });
        const bogusPaymentAssetContract = `${deployer.address}.bogus-ft`;
        const order: Order = { tokenId, expiry: 10, price, paymentAssetContract };
        const block = chain.mineBlock([
            whitelistAssetTx(nftAssetContract, true, deployer),
            whitelistAssetTx(paymentAssetContract, true, deployer),
            listOrderTx(nftAssetContract, maker, order),
            Tx.contractCall(contractName, 'fulfil-listing-ft', [types.uint(0), types.principal(nftAssetContract), types.principal(bogusPaymentAssetContract)], taker.address)
        ]);
        block.receipts[3].result.expectErr().expectUint(2004);
        assertEquals(block.receipts[3].events.length, 0);
    }
});

Insufficient balance

It should naturally be impossible to purchase an NFT if the buyer does not have sufficient payment asset balance. There should be no token events in such cases.

Clarinet.test({
    name: "Cannot fulfil an active STX listing with insufficient balance",
    async fn(chain: Chain, accounts: Map<string, Account>) {
        const [deployer, maker, taker] = ['deployer', 'wallet_1', 'wallet_2'].map(name => accounts.get(name)!);
        const { nftAssetContract, tokenId } = mintNft({ chain, deployer, recipient: maker });
        const order: Order = { tokenId, expiry: 10, price: taker.balance + 10 };
        const block = chain.mineBlock([
            whitelistAssetTx(nftAssetContract, true, deployer),
            listOrderTx(nftAssetContract, maker, order),
            Tx.contractCall(contractName, 'fulfil-listing-stx', [types.uint(0), types.principal(nftAssetContract)], taker.address)
        ]);
        block.receipts[2].result.expectErr().expectUint(1);
        assertEquals(block.receipts[2].events.length, 0);
    }
});

Clarinet.test({
    name: "Cannot fulfil an active SIP010 fungible token listing with insufficient balance",
    async fn(chain: Chain, accounts: Map<string, Account>) {
        const [deployer, maker, taker] = ['deployer', 'wallet_1', 'wallet_2'].map(name => accounts.get(name)!);
        const price = 50;
        const { nftAssetContract, tokenId } = mintNft({ chain, deployer, recipient: maker });
        const { paymentAssetContract } = mintFt({ chain, deployer, recipient: taker, amount: price });
        const order: Order = { tokenId, expiry: 10, price: taker.balance + 10, paymentAssetContract };
        const block = chain.mineBlock([
            whitelistAssetTx(nftAssetContract, true, deployer),
            whitelistAssetTx(paymentAssetContract, true, deployer),
            listOrderTx(nftAssetContract, maker, order),
            Tx.contractCall(contractName, 'fulfil-listing-ft', [types.uint(0), types.principal(nftAssetContract), types.principal(paymentAssetContract)], taker.address)
        ]);
        block.receipts[3].result.expectErr().expectUint(1);
        assertEquals(block.receipts[3].events.length, 0);
    }
});

Intended taker

Sellers have the ability to list an NFT for sale that only one specific principal can purchase, by setting the "intended taker" field. Another two tests are in order: one where an intended taker is indeed able to fulfil a listing, and another where an unintended take is not able to fulfil the listing.

Clarinet.test({
    name: "Intended taker can fulfil active listing",
    async fn(chain: Chain, accounts: Map<string, Account>) {
        const [deployer, maker, taker] = ['deployer', 'wallet_1', 'wallet_2'].map(name => accounts.get(name)!);
        const { nftAssetContract, tokenId } = mintNft({ chain, deployer, recipient: maker });
        const order: Order = { tokenId, expiry: 10, price: 10, taker: taker.address };
        const block = chain.mineBlock([
            whitelistAssetTx(nftAssetContract, true, deployer),
            listOrderTx(nftAssetContract, maker, order),
            Tx.contractCall(contractName, 'fulfil-listing-stx', [types.uint(0), types.principal(nftAssetContract)], taker.address)
        ]);
        block.receipts[2].result.expectOk().expectUint(0);
        assertNftTransfer(block.receipts[2].events[0], nftAssetContract, tokenId, contractPrincipal(deployer), taker.address);
        block.receipts[2].events.expectSTXTransferEvent(order.price, taker.address, maker.address);
    }
});

Clarinet.test({
    name: "Unintended taker cannot fulfil active listing",
    async fn(chain: Chain, accounts: Map<string, Account>) {
        const [deployer, maker, taker, unintendedTaker] = ['deployer', 'wallet_1', 'wallet_2', 'wallet_3'].map(name => accounts.get(name)!);
        const { nftAssetContract, tokenId } = mintNft({ chain, deployer, recipient: maker });
        const order: Order = { tokenId, expiry: 10, price: 10, taker: taker.address };
        const block = chain.mineBlock([
            whitelistAssetTx(nftAssetContract, true, deployer),
            listOrderTx(nftAssetContract, maker, order),
            Tx.contractCall(contractName, 'fulfil-listing-stx', [types.uint(0), types.principal(nftAssetContract)], unintendedTaker.address)
        ]);
        block.receipts[2].result.expectErr().expectUint(2006);
        assertEquals(block.receipts[2].events.length, 0);
    }
});

Multiple orders

We add one final bonus test that fulfils a few random listings in a random order. It can be useful to catch bugs that might not arise in a controller state with one listing and one purchase.

Clarinet.test({
    name: "Can fulfil multiple active listings in any order",
    async fn(chain: Chain, accounts: Map<string, Account>) {
        const deployer = accounts.get('deployer')!;
        const expiry = 100;

        const randomSorter = () => Math.random() - .5;

        // Take some makers and takers in random order.
        const makers = ['wallet_1', 'wallet_2', 'wallet_3', 'wallet_4'].sort(randomSorter).map(name => accounts.get(name)!);
        const takers = ['wallet_5', 'wallet_6', 'wallet_7', 'wallet_8'].sort(randomSorter).map(name => accounts.get(name)!);

        // Mint some NFTs so the IDs do not always start at zero.
        const mints = [...Array(1 + ~~(Math.random() * 10))].map(() => mintNft({ chain, deployer, recipient: deployer }));

        // Mint an NFT for all makers and generate orders.
        const nfts = makers.map(recipient => mintNft({ chain, deployer, recipient }));
        const orders: Order[] = makers.map((maker, i) => ({ tokenId: nfts[i].tokenId, expiry, price: 1 + ~~(Math.random() * 10) }));

        // Whitelist asset contract
        chain.mineBlock([whitelistAssetTx(mints[0].nftAssetContract, true, deployer)]);

        // List all NFTs.
        const block = chain.mineBlock(
            makers.map((maker, i) => listOrderTx(nfts[i].nftAssetContract, maker, makeOrder(orders[i])))
        );
        const orderIdUints = block.receipts.map(receipt => receipt.result.expectOk().toString());

        // Attempt to fulfil all listings.
        const block2 = chain.mineBlock(
            takers.map((taker, i) => Tx.contractCall(contractName, 'fulfil-listing-stx', [orderIdUints[i], types.principal(nfts[i].nftAssetContract)], taker.address))
        );

        const contractAddress = contractPrincipal(deployer);

        // Assert that all orders were fulfilled and that the NFTs and STX have been tranferred to the appropriate principals.
        block2.receipts.map((receipt, i) => {
            assertEquals(receipt.result.expectOk(), orderIdUints[i]);
            assertNftTransfer(receipt.events[0], nfts[i].nftAssetContract, nfts[i].tokenId, contractAddress, takers[i].address);
            receipt.events.expectSTXTransferEvent(orders[i].price, takers[i].address, makers[i].address);
        });
    }
});

That was quite a lot, but there we are!