AccountDelete_test.cpp

#include <test/jtx.h>
 
#include <xrpl/protocol/Feature.h>
#include <xrpl/protocol/jss.h>
 
namespace xrpl {
namespace test {
 
class AccountDelete_test : public beast::unit_test::suite
{
private:
    // Helper function that verifies the expected DeliveredAmount is present.
    //
    // NOTE: the function _infers_ the transaction to operate on by calling
    // env.tx(), which returns the result from the most recent transaction.
    void
    verifyDeliveredAmount(jtx::Env& env, STAmount const& amount)
    {
        // Get the hash for the most recent transaction.
        std::string const txHash{env.tx()->getJson(JsonOptions::none)[jss::hash].asString()};
 
        // Verify DeliveredAmount and delivered_amount metadata are correct.
        // We can't use env.meta() here, because meta() doesn't include
        // delivered_amount.
        env.close();
        Json::Value const meta = env.rpc("tx", txHash)[jss::result][jss::meta];
 
        // Expect there to be a DeliveredAmount field.
        if (!BEAST_EXPECT(meta.isMember(sfDeliveredAmount.jsonName)))
            return;
 
        // DeliveredAmount and delivered_amount should both be present and
        // equal amount.
        Json::Value const jsonExpect{amount.getJson(JsonOptions::none)};
        BEAST_EXPECT(meta[sfDeliveredAmount.jsonName] == jsonExpect);
        BEAST_EXPECT(meta[jss::delivered_amount] == jsonExpect);
    }
 
    // Helper function to create a payment channel.
    static Json::Value
    payChanCreate(
        jtx::Account const& account,
        jtx::Account const& to,
        STAmount const& amount,
        NetClock::duration const& settleDelay,
        NetClock::time_point const& cancelAfter,
        PublicKey const& pk)
    {
        Json::Value jv;
        jv[jss::TransactionType] = jss::PaymentChannelCreate;
        jv[jss::Account] = account.human();
        jv[jss::Destination] = to.human();
        jv[jss::Amount] = amount.getJson(JsonOptions::none);
        jv[sfSettleDelay.jsonName] = settleDelay.count();
        jv[sfCancelAfter.jsonName] = cancelAfter.time_since_epoch().count() + 2;
        jv[sfPublicKey.jsonName] = strHex(pk.slice());
        return jv;
    };
 
public:
    void
    testBasics()
    {
        using namespace jtx;
 
        testcase("Basics");
 
        Env env{*this};
        Account const alice("alice");
        Account const becky("becky");
        Account const carol("carol");
        Account const gw("gw");
 
        env.fund(XRP(10000), alice, becky, carol, gw);
        env.close();
 
        // Alice can't delete her account and then give herself the XRP.
        env(acctdelete(alice, alice), ter(temDST_IS_SRC));
 
        // alice can't delete her account with a negative fee.
        env(acctdelete(alice, becky), fee(drops(-1)), ter(temBAD_FEE));
 
        // Invalid flags.
        env(acctdelete(alice, becky), txflags(tfImmediateOrCancel), ter(temINVALID_FLAG));
 
        // Account deletion has a high fee.  Make sure the fee requirement
        // behaves as we expect.
        auto const acctDelFee{drops(env.current()->fees().increment)};
        env(acctdelete(alice, becky), ter(telINSUF_FEE_P));
 
        // Try a fee one drop less than the required amount.
        env(acctdelete(alice, becky), fee(acctDelFee - drops(1)), ter(telINSUF_FEE_P));
 
        // alice's account is created too recently to be deleted.
        env(acctdelete(alice, becky), fee(acctDelFee), ter(tecTOO_SOON));
 
        // Give becky a trustline.  She is no longer deletable.
        env(trust(becky, gw["USD"](1000)));
        env.close();
 
        // Give carol a deposit pre-authorization, an offer, a ticket,
        // a signer list, and a DID.  Even with all that she's still deletable.
        env(deposit::auth(carol, becky));
        std::uint32_t const carolOfferSeq{env.seq(carol)};
        env(offer(carol, gw["USD"](51), XRP(51)));
        std::uint32_t const carolTicketSeq{env.seq(carol) + 1};
        env(ticket::create(carol, 1));
        env(signers(carol, 1, {{alice, 1}, {becky, 1}}));
        env(did::setValid(carol));
 
        // Deleting should fail with TOO_SOON, which is a relatively
        // cheap check compared to validating the contents of her directory.
        env(acctdelete(alice, becky), fee(acctDelFee), ter(tecTOO_SOON));
 
        // Close enough ledgers to almost be able to delete alice's account.
        incLgrSeqForAccDel(env, alice, 1);
 
        // alice's account is still created too recently to be deleted.
        env(acctdelete(alice, becky), fee(acctDelFee), ter(tecTOO_SOON));
 
        // The most recent delete attempt advanced alice's sequence.  So
        // close two ledgers and her account should be deletable.
        env.close();
        env.close();
 
        {
            auto const aliceOldBalance{env.balance(alice)};
            auto const beckyOldBalance{env.balance(becky)};
 
            // Verify that alice's account exists but she has no directory.
            BEAST_EXPECT(env.closed()->exists(keylet::account(alice.id())));
            BEAST_EXPECT(!env.closed()->exists(keylet::ownerDir(alice.id())));
 
            env(acctdelete(alice, becky), fee(acctDelFee));
            verifyDeliveredAmount(env, aliceOldBalance - acctDelFee);
            env.close();
 
            // Verify that alice's account and directory are actually gone.
            BEAST_EXPECT(!env.closed()->exists(keylet::account(alice.id())));
            BEAST_EXPECT(!env.closed()->exists(keylet::ownerDir(alice.id())));
 
            // Verify that alice's XRP, minus the fee, was transferred to becky.
            BEAST_EXPECT(env.balance(becky) == aliceOldBalance + beckyOldBalance - acctDelFee);
        }
 
        // Attempt to delete becky's account but get stopped by the trust line.
        env(acctdelete(becky, carol), fee(acctDelFee), ter(tecHAS_OBLIGATIONS));
        env.close();
 
        // Verify that becky's account is still there by giving her a regular
        // key.  This has the side effect of setting the lsfPasswordSpent bit
        // on her account root.
        Account const beck("beck");
        env(regkey(becky, beck), fee(drops(0)));
        env.close();
 
        // Show that the lsfPasswordSpent bit is set by attempting to change
        // becky's regular key for free again.  That fails.
        Account const reb("reb");
        env(regkey(becky, reb), sig(becky), fee(drops(0)), ter(telINSUF_FEE_P));
 
        // Close enough ledgers that becky's failing regkey transaction is
        // no longer retried.
        for (int i = 0; i < 8; ++i)
            env.close();
 
        {
            auto const beckyOldBalance{env.balance(becky)};
            auto const carolOldBalance{env.balance(carol)};
 
            // Verify that Carol's account, directory, deposit
            // pre-authorization, offer, ticket, and signer list exist.
            BEAST_EXPECT(env.closed()->exists(keylet::account(carol.id())));
            BEAST_EXPECT(env.closed()->exists(keylet::ownerDir(carol.id())));
            BEAST_EXPECT(env.closed()->exists(keylet::depositPreauth(carol.id(), becky.id())));
            BEAST_EXPECT(env.closed()->exists(keylet::offer(carol.id(), carolOfferSeq)));
            BEAST_EXPECT(env.closed()->exists(keylet::ticket(carol.id(), carolTicketSeq)));
            BEAST_EXPECT(env.closed()->exists(keylet::signers(carol.id())));
 
            // Delete carol's account even with stuff in her directory.  Show
            // that multisigning for the delete does not increase carol's fee.
            env(acctdelete(carol, becky), fee(acctDelFee), msig(alice));
            verifyDeliveredAmount(env, carolOldBalance - acctDelFee);
            env.close();
 
            // Verify that Carol's account, directory, and other stuff are gone.
            BEAST_EXPECT(!env.closed()->exists(keylet::account(carol.id())));
            BEAST_EXPECT(!env.closed()->exists(keylet::ownerDir(carol.id())));
            BEAST_EXPECT(!env.closed()->exists(keylet::depositPreauth(carol.id(), becky.id())));
            BEAST_EXPECT(!env.closed()->exists(keylet::offer(carol.id(), carolOfferSeq)));
            BEAST_EXPECT(!env.closed()->exists(keylet::ticket(carol.id(), carolTicketSeq)));
            BEAST_EXPECT(!env.closed()->exists(keylet::signers(carol.id())));
 
            // Verify that Carol's XRP, minus the fee, was transferred to becky.
            BEAST_EXPECT(env.balance(becky) == carolOldBalance + beckyOldBalance - acctDelFee);
 
            // Since becky received an influx of XRP, her lsfPasswordSpent bit
            // is cleared and she can change her regular key for free again.
            env(regkey(becky, reb), sig(becky), fee(drops(0)));
        }
    }
 
    void
    testDirectories()
    {
        // The code that deletes consecutive directory entries uses a
        // peculiarity of the implementation.  Make sure that peculiarity
        // behaves as expected across owner directory pages.
        using namespace jtx;
 
        testcase("Directories");
 
        Env env{*this};
        Account const alice("alice");
        Account const gw("gw");
 
        env.fund(XRP(10000), alice, gw);
        env.close();
 
        // Alice creates enough offers to require two owner directories.
        for (int i{0}; i < 45; ++i)
        {
            env(offer(alice, gw["USD"](1), XRP(1)));
            env.close();
        }
        env.require(offers(alice, 45));
 
        // Close enough ledgers to be able to delete alice's account.
        incLgrSeqForAccDel(env, alice);
 
        // Verify that both directory nodes exist.
        Keylet const aliceRootKey{keylet::ownerDir(alice.id())};
        Keylet const alicePageKey{keylet::page(aliceRootKey, 1)};
        BEAST_EXPECT(env.closed()->exists(aliceRootKey));
        BEAST_EXPECT(env.closed()->exists(alicePageKey));
 
        // Delete alice's account.
        auto const acctDelFee{drops(env.current()->fees().increment)};
        auto const aliceBalance{env.balance(alice)};
        env(acctdelete(alice, gw), fee(acctDelFee));
        verifyDeliveredAmount(env, aliceBalance - acctDelFee);
        env.close();
 
        // Both of alice's directory nodes should be gone.
        BEAST_EXPECT(!env.closed()->exists(aliceRootKey));
        BEAST_EXPECT(!env.closed()->exists(alicePageKey));
    }
 
    void
    testOwnedTypes()
    {
        using namespace jtx;
 
        testcase("Owned types");
 
        // We want to test PayChannels with the backlink.
        Env env{*this, testable_amendments()};
        Account const alice("alice");
        Account const becky("becky");
        Account const gw("gw");
 
        env.fund(XRP(100000), alice, becky, gw);
        env.close();
 
        // Give alice and becky a bunch of offers that we have to search
        // through before we figure out that there's a non-deletable
        // entry in their directory.
        for (int i{0}; i < 200; ++i)
        {
            env(offer(alice, gw["USD"](1), XRP(1)));
            env(offer(becky, gw["USD"](1), XRP(1)));
            env.close();
        }
        env.require(offers(alice, 200));
        env.require(offers(becky, 200));
 
        // Close enough ledgers to be able to delete alice's and becky's
        // accounts.
        incLgrSeqForAccDel(env, alice);
        incLgrSeqForAccDel(env, becky);
 
        // alice writes a check to becky.  Until that check is cashed or
        // canceled it will prevent alice's and becky's accounts from being
        // deleted.
        uint256 const checkId = keylet::check(alice, env.seq(alice)).key;
        env(check::create(alice, becky, XRP(1)));
        env.close();
 
        auto const acctDelFee{drops(env.current()->fees().increment)};
        env(acctdelete(alice, gw), fee(acctDelFee), ter(tecHAS_OBLIGATIONS));
        env(acctdelete(becky, gw), fee(acctDelFee), ter(tecHAS_OBLIGATIONS));
        env.close();
 
        // Cancel the check, but add an escrow.  Again, with the escrow
        // on board, alice and becky should not be able to delete their
        // accounts.
        env(check::cancel(becky, checkId));
        env.close();
 
        using namespace std::chrono_literals;
        std::uint32_t const escrowSeq{env.seq(alice)};
        env(escrow::create(alice, becky, XRP(333)),
            escrow::finish_time(env.now() + 3s),
            escrow::cancel_time(env.now() + 4s));
        env.close();
 
        // alice and becky should be unable to delete their accounts because
        // of the escrow.
        env(acctdelete(alice, gw), fee(acctDelFee), ter(tecHAS_OBLIGATIONS));
        env(acctdelete(becky, gw), fee(acctDelFee), ter(tecHAS_OBLIGATIONS));
        env.close();
 
        // Now cancel the escrow, but create a payment channel between
        // alice and becky.
 
        bool const withTokenEscrow = env.current()->rules().enabled(featureTokenEscrow);
        if (withTokenEscrow)
        {
            Account const gw1("gw1");
            Account const carol("carol");
            auto const USD = gw1["USD"];
            env.fund(XRP(100000), carol, gw1);
            env(fset(gw1, asfAllowTrustLineLocking));
            env.close();
            env.trust(USD(10000), carol);
            env.close();
            env(pay(gw1, carol, USD(100)));
            env.close();
 
            std::uint32_t const escrowSeq{env.seq(carol)};
            env(escrow::create(carol, becky, USD(1)),
                escrow::finish_time(env.now() + 3s),
                escrow::cancel_time(env.now() + 4s));
            env.close();
 
            incLgrSeqForAccDel(env, gw1);
 
            env(acctdelete(gw1, becky), fee(acctDelFee), ter(tecHAS_OBLIGATIONS));
            env.close();
 
            env(escrow::cancel(becky, carol, escrowSeq));
            env.close();
        }
 
        env(escrow::cancel(becky, alice, escrowSeq));
        env.close();
 
        Keylet const alicePayChanKey{keylet::payChan(alice, becky, env.seq(alice))};
 
        env(payChanCreate(alice, becky, XRP(57), 4s, env.now() + 2s, alice.pk()));
        env.close();
 
        // With the PayChannel in place becky and alice should not be
        // able to delete her account
        auto const beckyBalance{env.balance(becky)};
        env(acctdelete(alice, gw), fee(acctDelFee), ter(tecHAS_OBLIGATIONS));
        env(acctdelete(becky, gw), fee(acctDelFee), ter(tecHAS_OBLIGATIONS));
        env.close();
 
        // Alice cancels her PayChannel, which will leave her with only offers
        // in her directory.
 
        // Lambda to close a PayChannel.
        auto payChanClose =
            [](jtx::Account const& account, Keylet const& payChanKeylet, PublicKey const& pk) {
                Json::Value jv;
                jv[jss::TransactionType] = jss::PaymentChannelClaim;
                jv[jss::Flags] = tfClose;
                jv[jss::Account] = account.human();
                jv[sfChannel.jsonName] = to_string(payChanKeylet.key);
                jv[sfPublicKey.jsonName] = strHex(pk.slice());
                return jv;
            };
        env(payChanClose(alice, alicePayChanKey, alice.pk()));
        env.close();
 
        // gw creates a PayChannel with alice as the destination, this should
        // prevent alice from deleting her account.
        Keylet const gwPayChanKey{keylet::payChan(gw, alice, env.seq(gw))};
 
        env(payChanCreate(gw, alice, XRP(68), 4s, env.now() + 2s, alice.pk()));
        env.close();
 
        // alice can't delete her account because of the PayChannel.
        env(acctdelete(alice, gw), fee(acctDelFee), ter(tecHAS_OBLIGATIONS));
        env.close();
 
        // alice closes the PayChannel which should (finally) allow her to
        // delete her account.
        env(payChanClose(alice, gwPayChanKey, alice.pk()));
        env.close();
 
        // Now alice can successfully delete her account.
        auto const aliceBalance{env.balance(alice)};
        env(acctdelete(alice, gw), fee(acctDelFee));
        verifyDeliveredAmount(env, aliceBalance - acctDelFee);
        env.close();
    }
 
    void
    testTooManyOffers()
    {
        // Put enough offers in an account that we refuse to delete the account.
        using namespace jtx;
 
        testcase("Too many offers");
 
        Env env{*this};
        Account const alice("alice");
        Account const gw("gw");
 
        // Fund alice well so she can afford the reserve on the offers.
        env.fund(XRP(10000000), alice, gw);
        env.close();
 
        // To increase the number of Books affected, change the currency of
        // each offer.
        std::string currency{"AAA"};
 
        // Alice creates 1001 offers.  This is one greater than the number of
        // directory entries an AccountDelete will remove.
        std::uint32_t const offerSeq0{env.seq(alice)};
        constexpr int offerCount{1001};
        for (int i{0}; i < offerCount; ++i)
        {
            env(offer(alice, gw[currency](1), XRP(1)));
            env.close();
 
            // Increment to next currency.
            ++currency[0];
            if (currency[0] > 'Z')
            {
                currency[0] = 'A';
                ++currency[1];
            }
            if (currency[1] > 'Z')
            {
                currency[1] = 'A';
                ++currency[2];
            }
            if (currency[2] > 'Z')
            {
                currency[0] = 'A';
                currency[1] = 'A';
                currency[2] = 'A';
            }
        }
 
        // Close enough ledgers to be able to delete alice's account.
        incLgrSeqForAccDel(env, alice);
 
        // Verify the existence of the expected ledger entries.
        Keylet const aliceOwnerDirKey{keylet::ownerDir(alice.id())};
        {
            std::shared_ptr<ReadView const> const closed{env.closed()};
            BEAST_EXPECT(closed->exists(keylet::account(alice.id())));
            BEAST_EXPECT(closed->exists(aliceOwnerDirKey));
 
            // alice's directory nodes.
            for (std::uint32_t i{0}; i < ((offerCount / 32) + 1); ++i)
                BEAST_EXPECT(closed->exists(keylet::page(aliceOwnerDirKey, i)));
 
            // alice's offers.
            for (std::uint32_t i{0}; i < offerCount; ++i)
                BEAST_EXPECT(closed->exists(keylet::offer(alice.id(), offerSeq0 + i)));
        }
 
        // Delete alice's account.  Should fail because she has too many
        // offers in her directory.
        auto const acctDelFee{drops(env.current()->fees().increment)};
 
        env(acctdelete(alice, gw), fee(acctDelFee), ter(tefTOO_BIG));
 
        // Cancel one of alice's offers.  Then the account delete can succeed.
        env.require(offers(alice, offerCount));
        env(offer_cancel(alice, offerSeq0));
        env.close();
        env.require(offers(alice, offerCount - 1));
 
        // alice successfully deletes her account.
        auto const alicePreDelBal{env.balance(alice)};
        env(acctdelete(alice, gw), fee(acctDelFee));
        verifyDeliveredAmount(env, alicePreDelBal - acctDelFee);
        env.close();
 
        // Verify that alice's account root is gone as well as her directory
        // nodes and all of her offers.
        {
            std::shared_ptr<ReadView const> const closed{env.closed()};
            BEAST_EXPECT(!closed->exists(keylet::account(alice.id())));
            BEAST_EXPECT(!closed->exists(aliceOwnerDirKey));
 
            // alice's former directory nodes.
            for (std::uint32_t i{0}; i < ((offerCount / 32) + 1); ++i)
                BEAST_EXPECT(!closed->exists(keylet::page(aliceOwnerDirKey, i)));
 
            // alice's former offers.
            for (std::uint32_t i{0}; i < offerCount; ++i)
                BEAST_EXPECT(!closed->exists(keylet::offer(alice.id(), offerSeq0 + i)));
        }
    }
 
    void
    testImplicitlyCreatedTrustline()
    {
        // Show that a trust line that is implicitly created by offer crossing
        // prevents an account from being deleted.
        using namespace jtx;
 
        testcase("Implicitly created trust line");
 
        Env env{*this};
        Account const alice{"alice"};
        Account const gw{"gw"};
        auto const BUX{gw["BUX"]};
 
        env.fund(XRP(10000), alice, gw);
        env.close();
 
        // alice creates an offer that, if crossed, will implicitly create
        // a trust line.
        env(offer(alice, BUX(30), XRP(30)));
        env.close();
 
        // gw crosses alice's offer.  alice should end up with BUX(30).
        env(offer(gw, XRP(30), BUX(30)));
        env.close();
        env.require(balance(alice, BUX(30)));
 
        // Close enough ledgers to be able to delete alice's account.
        incLgrSeqForAccDel(env, alice);
 
        // alice and gw can't delete their accounts because of the implicitly
        // created trust line.
        auto const acctDelFee{drops(env.current()->fees().increment)};
        env(acctdelete(alice, gw), fee(acctDelFee), ter(tecHAS_OBLIGATIONS));
        env.close();
 
        env(acctdelete(gw, alice), fee(acctDelFee), ter(tecHAS_OBLIGATIONS));
        env.close();
        {
            std::shared_ptr<ReadView const> const closed{env.closed()};
            BEAST_EXPECT(closed->exists(keylet::account(alice.id())));
            BEAST_EXPECT(closed->exists(keylet::account(gw.id())));
        }
    }
 
    void
    testBalanceTooSmallForFee()
    {
        // See what happens when an account with a balance less than the
        // incremental reserve tries to delete itself.
        using namespace jtx;
 
        testcase("Balance too small for fee");
 
        Env env{*this};
        Account const alice("alice");
 
        // Note that the fee structure for unit tests does not match the fees
        // on the production network (October 2019).  Unit tests have a base
        // reserve of 200 XRP.
        env.fund(env.current()->fees().reserve, noripple(alice));
        env.close();
 
        // Burn a chunk of alice's funds so she only has 1 XRP remaining in
        // her account.
        env(noop(alice), fee(env.balance(alice) - XRP(1)));
        env.close();
 
        auto const acctDelFee{drops(env.current()->fees().increment)};
        BEAST_EXPECT(acctDelFee > env.balance(alice));
 
        // alice attempts to delete her account even though she can't pay
        // the full fee.  She specifies a fee that is larger than her balance.
        //
        // The balance of env.master should not change.
        auto const masterBalance{env.balance(env.master)};
        env(acctdelete(alice, env.master), fee(acctDelFee), ter(terINSUF_FEE_B));
        env.close();
        {
            std::shared_ptr<ReadView const> const closed{env.closed()};
            BEAST_EXPECT(closed->exists(keylet::account(alice.id())));
            BEAST_EXPECT(env.balance(env.master) == masterBalance);
        }
 
        // alice again attempts to delete her account.  This time she specifies
        // her current balance in XRP.  Again the transaction fails.
        BEAST_EXPECT(env.balance(alice) == XRP(1));
        env(acctdelete(alice, env.master), fee(XRP(1)), ter(telINSUF_FEE_P));
        env.close();
        {
            std::shared_ptr<ReadView const> const closed{env.closed()};
            BEAST_EXPECT(closed->exists(keylet::account(alice.id())));
            BEAST_EXPECT(env.balance(env.master) == masterBalance);
        }
    }
 
    void
    testWithTickets()
    {
        testcase("With Tickets");
 
        using namespace test::jtx;
 
        Account const alice{"alice"};
        Account const bob{"bob"};
 
        Env env{*this};
        env.fund(XRP(100000), alice, bob);
        env.close();
 
        // bob grabs as many tickets as he is allowed to have.
        std::uint32_t const ticketSeq{env.seq(bob) + 1};
        env(ticket::create(bob, 250));
        env.close();
        env.require(owners(bob, 250));
 
        {
            std::shared_ptr<ReadView const> const closed{env.closed()};
            BEAST_EXPECT(closed->exists(keylet::account(bob.id())));
            for (std::uint32_t i = 0; i < 250; ++i)
            {
                BEAST_EXPECT(closed->exists(keylet::ticket(bob.id(), ticketSeq + i)));
            }
        }
 
        // Close enough ledgers to be able to delete bob's account.
        incLgrSeqForAccDel(env, bob);
 
        // bob deletes his account using a ticket.  bob's account and all
        // of his tickets should be removed from the ledger.
        auto const acctDelFee{drops(env.current()->fees().increment)};
        auto const bobOldBalance{env.balance(bob)};
        env(acctdelete(bob, alice), ticket::use(ticketSeq), fee(acctDelFee));
        verifyDeliveredAmount(env, bobOldBalance - acctDelFee);
        env.close();
        {
            std::shared_ptr<ReadView const> const closed{env.closed()};
            BEAST_EXPECT(!closed->exists(keylet::account(bob.id())));
            for (std::uint32_t i = 0; i < 250; ++i)
            {
                BEAST_EXPECT(!closed->exists(keylet::ticket(bob.id(), ticketSeq + i)));
            }
        }
    }
 
    void
    testDest()
    {
        testcase("Destination Constraints");
 
        using namespace test::jtx;
 
        Account const alice{"alice"};
        Account const becky{"becky"};
        Account const carol{"carol"};
        Account const daria{"daria"};
 
        Env env{*this};
        env.fund(XRP(100000), alice, becky, carol);
        env.close();
 
        // alice sets the lsfDepositAuth flag on her account.  This should
        // prevent becky from deleting her account while using alice as the
        // destination.
        env(fset(alice, asfDepositAuth));
 
        // carol requires a destination tag.
        env(fset(carol, asfRequireDest));
        env.close();
 
        // Close enough ledgers to be able to delete becky's account.
        incLgrSeqForAccDel(env, becky);
 
        // becky attempts to delete her account using daria as the destination.
        // Since daria is not in the ledger the delete attempt fails.
        auto const acctDelFee{drops(env.current()->fees().increment)};
        env(acctdelete(becky, daria), fee(acctDelFee), ter(tecNO_DST));
        env.close();
 
        // becky attempts to delete her account, but carol requires a
        // destination tag which becky has omitted.
        env(acctdelete(becky, carol), fee(acctDelFee), ter(tecDST_TAG_NEEDED));
        env.close();
 
        // becky attempts to delete her account, but alice won't take her XRP,
        // so the delete is blocked.
        env(acctdelete(becky, alice), fee(acctDelFee), ter(tecNO_PERMISSION));
        env.close();
 
        // alice preauthorizes deposits from becky.  Now becky can delete her
        // account and forward the leftovers to alice.
        env(deposit::auth(alice, becky));
        env.close();
 
        auto const beckyOldBalance{env.balance(becky)};
        env(acctdelete(becky, alice), fee(acctDelFee));
        verifyDeliveredAmount(env, beckyOldBalance - acctDelFee);
        env.close();
    }
 
    void
    testDestinationDepositAuthCredentials()
    {
        {
            testcase("Destination Constraints with DepositPreauth and Credentials");
 
            using namespace test::jtx;
 
            Account const alice{"alice"};
            Account const becky{"becky"};
            Account const carol{"carol"};
            Account const daria{"daria"};
 
            char const credType[] = "abcd";
 
            Env env{*this};
            env.fund(XRP(100000), alice, becky, carol, daria);
            env.close();
 
            // carol issue credentials for becky
            env(credentials::create(becky, carol, credType));
            env.close();
 
            // get credentials index
            auto const jv = credentials::ledgerEntry(env, becky, carol, credType);
            std::string const credIdx = jv[jss::result][jss::index].asString();
 
            // Close enough ledgers to be able to delete becky's account.
            incLgrSeqForAccDel(env, becky);
 
            auto const acctDelFee{drops(env.current()->fees().increment)};
 
            // becky use credentials but they aren't accepted
            env(acctdelete(becky, alice),
                credentials::ids({credIdx}),
                fee(acctDelFee),
                ter(tecBAD_CREDENTIALS));
            env.close();
 
            {
                // alice sets the lsfDepositAuth flag on her account.  This
                // should prevent becky from deleting her account while using
                // alice as the destination.
                env(fset(alice, asfDepositAuth));
                env.close();
            }
 
            // Fail, credentials still not accepted
            env(acctdelete(becky, alice),
                credentials::ids({credIdx}),
                fee(acctDelFee),
                ter(tecBAD_CREDENTIALS));
            env.close();
 
            // becky accept the credentials
            env(credentials::accept(becky, carol, credType));
            env.close();
 
            // Fail, credentials doesn’t belong to carol
            env(acctdelete(carol, alice),
                credentials::ids({credIdx}),
                fee(acctDelFee),
                ter(tecBAD_CREDENTIALS));
 
            // Fail, no depositPreauth for provided credentials
            env(acctdelete(becky, alice),
                credentials::ids({credIdx}),
                fee(acctDelFee),
                ter(tecNO_PERMISSION));
            env.close();
 
            // alice create DepositPreauth Object
            env(deposit::authCredentials(alice, {{carol, credType}}));
            env.close();
 
            // becky attempts to delete her account, but alice won't take her
            // XRP, so the delete is blocked.
            env(acctdelete(becky, alice), fee(acctDelFee), ter(tecNO_PERMISSION));
 
            // becky use empty credentials and can't delete account
            env(acctdelete(becky, alice), fee(acctDelFee), credentials::ids({}), ter(temMALFORMED));
 
            // becky use bad credentials and can't delete account
            env(acctdelete(becky, alice),
                credentials::ids({"48004829F915654A81B11C4AB8218D96FED67F209B58328A72314FB6E"
                                  "A288BE4"}),
                fee(acctDelFee),
                ter(tecBAD_CREDENTIALS));
            env.close();
 
            // becky use credentials and can delete account
            env(acctdelete(becky, alice), credentials::ids({credIdx}), fee(acctDelFee));
            env.close();
 
            {
                // check that credential object deleted too
                auto const jNoCred = credentials::ledgerEntry(env, becky, carol, credType);
                BEAST_EXPECT(
                    jNoCred.isObject() && jNoCred.isMember(jss::result) &&
                    jNoCred[jss::result].isMember(jss::error) &&
                    jNoCred[jss::result][jss::error] == "entryNotFound");
            }
 
            testcase("Credentials that aren't required");
            {  // carol issue credentials for daria
                env(credentials::create(daria, carol, credType));
                env.close();
                env(credentials::accept(daria, carol, credType));
                env.close();
                std::string const credDaria =
                    credentials::ledgerEntry(env, daria, carol, credType)[jss::result][jss::index]
                        .asString();
 
                // daria use valid credentials, which aren't required and can
                // delete her account
                env(acctdelete(daria, carol), credentials::ids({credDaria}), fee(acctDelFee));
                env.close();
 
                // check that credential object deleted too
                auto const jNoCred = credentials::ledgerEntry(env, daria, carol, credType);
 
                BEAST_EXPECT(
                    jNoCred.isObject() && jNoCred.isMember(jss::result) &&
                    jNoCred[jss::result].isMember(jss::error) &&
                    jNoCred[jss::result][jss::error] == "entryNotFound");
            }
 
            {
                Account const eaton{"eaton"};
                Account const fred{"fred"};
 
                env.fund(XRP(5000), eaton, fred);
 
                // carol issue credentials for eaton
                env(credentials::create(eaton, carol, credType));
                env.close();
                env(credentials::accept(eaton, carol, credType));
                env.close();
                std::string const credEaton =
                    credentials::ledgerEntry(env, eaton, carol, credType)[jss::result][jss::index]
                        .asString();
 
                // fred make pre-authorization through authorized account
                env(fset(fred, asfDepositAuth));
                env.close();
                env(deposit::auth(fred, eaton));
                env.close();
 
                // Close enough ledgers to be able to delete becky's account.
                incLgrSeqForAccDel(env, eaton);
                auto const acctDelFee{drops(env.current()->fees().increment)};
 
                // eaton use valid credentials, but he already authorized
                // through "Authorized" field.
                env(acctdelete(eaton, fred), credentials::ids({credEaton}), fee(acctDelFee));
                env.close();
 
                // check that credential object deleted too
                auto const jNoCred = credentials::ledgerEntry(env, eaton, carol, credType);
 
                BEAST_EXPECT(
                    jNoCred.isObject() && jNoCred.isMember(jss::result) &&
                    jNoCred[jss::result].isMember(jss::error) &&
                    jNoCred[jss::result][jss::error] == "entryNotFound");
            }
 
            testcase("Expired credentials");
            {
                Account const john{"john"};
 
                env.fund(XRP(10000), john);
                env.close();
 
                auto jv = credentials::create(john, carol, credType);
                uint32_t const t =
                    env.current()->header().parentCloseTime.time_since_epoch().count() + 20;
                jv[sfExpiration.jsonName] = t;
                env(jv);
                env.close();
                env(credentials::accept(john, carol, credType));
                env.close();
                jv = credentials::ledgerEntry(env, john, carol, credType);
                std::string const credIdx = jv[jss::result][jss::index].asString();
 
                incLgrSeqForAccDel(env, john);
 
                // credentials are expired
                // john use credentials but can't delete account
                env(acctdelete(john, alice),
                    credentials::ids({credIdx}),
                    fee(acctDelFee),
                    ter(tecEXPIRED));
                env.close();
 
                {
                    // check that expired credential object deleted
                    auto jv = credentials::ledgerEntry(env, john, carol, credType);
                    BEAST_EXPECT(
                        jv.isObject() && jv.isMember(jss::result) &&
                        jv[jss::result].isMember(jss::error) &&
                        jv[jss::result][jss::error] == "entryNotFound");
                }
            }
        }
 
        {
            testcase("Credentials feature disabled");
            using namespace test::jtx;
 
            Account const alice{"alice"};
            Account const becky{"becky"};
            Account const carol{"carol"};
 
            Env env{*this, testable_amendments() - featureCredentials};
            env.fund(XRP(100000), alice, becky, carol);
            env.close();
 
            // alice sets the lsfDepositAuth flag on her account.  This should
            // prevent becky from deleting her account while using alice as the
            // destination.
            env(fset(alice, asfDepositAuth));
            env.close();
 
            // Close enough ledgers to be able to delete becky's account.
            incLgrSeqForAccDel(env, becky);
 
            auto const acctDelFee{drops(env.current()->fees().increment)};
 
            std::string const credIdx =
                "098B7F1B146470A1C5084DC7832C04A72939E3EBC58E68AB8B579BA072B0CE"
                "CB";
 
            // and can't delete even with old DepositPreauth
            env(deposit::auth(alice, becky));
            env.close();
 
            env(acctdelete(becky, alice),
                credentials::ids({credIdx}),
                fee(acctDelFee),
                ter(temDISABLED));
            env.close();
        }
    }
 
    void
    testDeleteCredentialsOwner()
    {
        {
            testcase("Deleting Issuer deletes issued credentials");
 
            using namespace test::jtx;
 
            Account const alice{"alice"};
            Account const becky{"becky"};
            Account const carol{"carol"};
 
            char const credType[] = "abcd";
 
            Env env{*this};
            env.fund(XRP(100000), alice, becky, carol);
            env.close();
 
            // carol issue credentials for becky
            env(credentials::create(becky, carol, credType));
            env.close();
            env(credentials::accept(becky, carol, credType));
            env.close();
 
            // get credentials index
            auto const jv = credentials::ledgerEntry(env, becky, carol, credType);
            std::string const credIdx = jv[jss::result][jss::index].asString();
 
            // Close enough ledgers to be able to delete carol's account.
            incLgrSeqForAccDel(env, carol);
 
            auto const acctDelFee{drops(env.current()->fees().increment)};
            env(acctdelete(carol, alice), fee(acctDelFee));
            env.close();
 
            {  // check that credential object deleted too
                BEAST_EXPECT(!env.le(credIdx));
                auto const jv = credentials::ledgerEntry(env, becky, carol, credType);
                BEAST_EXPECT(
                    jv.isObject() && jv.isMember(jss::result) &&
                    jv[jss::result].isMember(jss::error) &&
                    jv[jss::result][jss::error] == "entryNotFound");
            }
        }
 
        {
            testcase("Deleting Subject deletes issued credentials");
 
            using namespace test::jtx;
 
            Account const alice{"alice"};
            Account const becky{"becky"};
            Account const carol{"carol"};
 
            char const credType[] = "abcd";
 
            Env env{*this};
            env.fund(XRP(100000), alice, becky, carol);
            env.close();
 
            // carol issue credentials for becky
            env(credentials::create(becky, carol, credType));
            env.close();
            env(credentials::accept(becky, carol, credType));
            env.close();
 
            // get credentials index
            auto const jv = credentials::ledgerEntry(env, becky, carol, credType);
            std::string const credIdx = jv[jss::result][jss::index].asString();
 
            // Close enough ledgers to be able to delete carol's account.
            incLgrSeqForAccDel(env, becky);
 
            auto const acctDelFee{drops(env.current()->fees().increment)};
            env(acctdelete(becky, alice), fee(acctDelFee));
            env.close();
 
            {  // check that credential object deleted too
                BEAST_EXPECT(!env.le(credIdx));
                auto const jv = credentials::ledgerEntry(env, becky, carol, credType);
                BEAST_EXPECT(
                    jv.isObject() && jv.isMember(jss::result) &&
                    jv[jss::result].isMember(jss::error) &&
                    jv[jss::result][jss::error] == "entryNotFound");
            }
        }
    }
 
    void
    run() override
    {
        testBasics();
        testDirectories();
        testOwnedTypes();
        testTooManyOffers();
        testImplicitlyCreatedTrustline();
        testBalanceTooSmallForFee();
        testWithTickets();
        testDest();
        testDestinationDepositAuthCredentials();
        testDeleteCredentialsOwner();
    }
};
 
BEAST_DEFINE_TESTSUITE_PRIO(AccountDelete, app, xrpl, 2);
 
}  // namespace test
}  // namespace xrpl