LCOV - code coverage report
Current view: top level - src/wallet/test - coinselector_tests.cpp (source / functions) Coverage Total Hit
Test: total_coverage.info Lines: 97.4 % 1005 979
Test Date: 2024-11-04 05:10:19 Functions: 100.0 % 57 57
Branches: 51.8 % 3256 1685

             Branch data     Line data    Source code
       1                 :             : // Copyright (c) 2017-2022 The Bitcoin Core developers
       2                 :             : // Distributed under the MIT software license, see the accompanying
       3                 :             : // file COPYING or http://www.opensource.org/licenses/mit-license.php.
       4                 :             : 
       5                 :             : #include <consensus/amount.h>
       6                 :             : #include <node/context.h>
       7                 :             : #include <policy/policy.h>
       8                 :             : #include <primitives/transaction.h>
       9                 :             : #include <random.h>
      10                 :             : #include <test/util/setup_common.h>
      11                 :             : #include <util/translation.h>
      12                 :             : #include <wallet/coincontrol.h>
      13                 :             : #include <wallet/coinselection.h>
      14                 :             : #include <wallet/spend.h>
      15                 :             : #include <wallet/test/util.h>
      16                 :             : #include <wallet/test/wallet_test_fixture.h>
      17                 :             : #include <wallet/wallet.h>
      18                 :             : 
      19                 :             : #include <algorithm>
      20                 :             : #include <boost/test/unit_test.hpp>
      21                 :             : #include <random>
      22                 :             : 
      23                 :             : namespace wallet {
      24                 :             : BOOST_FIXTURE_TEST_SUITE(coinselector_tests, WalletTestingSetup)
      25                 :             : 
      26                 :             : // how many times to run all the tests to have a chance to catch errors that only show up with particular random shuffles
      27                 :             : #define RUN_TESTS 100
      28                 :             : 
      29                 :             : // some tests fail 1% of the time due to bad luck.
      30                 :             : // we repeat those tests this many times and only complain if all iterations of the test fail
      31                 :             : #define RANDOM_REPEATS 5
      32                 :             : 
      33                 :             : typedef std::set<std::shared_ptr<COutput>> CoinSet;
      34                 :             : 
      35                 :             : static const CoinEligibilityFilter filter_standard(1, 6, 0);
      36                 :             : static const CoinEligibilityFilter filter_confirmed(1, 1, 0);
      37                 :             : static const CoinEligibilityFilter filter_standard_extra(6, 6, 0);
      38                 :             : static int nextLockTime = 0;
      39                 :             : 
      40                 :       50088 : static void add_coin(const CAmount& nValue, int nInput, std::vector<COutput>& set)
      41                 :             : {
      42                 :       50088 :     CMutableTransaction tx;
      43         [ +  - ]:       50088 :     tx.vout.resize(nInput + 1);
      44         [ +  - ]:       50088 :     tx.vout[nInput].nValue = nValue;
      45                 :       50088 :     tx.nLockTime = nextLockTime++;        // so all transactions get different hashes
      46   [ +  -  +  -  :       50088 :     set.emplace_back(COutPoint(tx.GetHash(), nInput), tx.vout.at(nInput), /*depth=*/ 1, /*input_bytes=*/ -1, /*spendable=*/ true, /*solvable=*/ true, /*safe=*/ true, /*time=*/ 0, /*from_me=*/ false, /*fees=*/ 0);
                   +  - ]
      47                 :       50088 : }
      48                 :             : 
      49                 :          33 : static void add_coin(const CAmount& nValue, int nInput, SelectionResult& result)
      50                 :             : {
      51                 :          33 :     CMutableTransaction tx;
      52         [ +  - ]:          33 :     tx.vout.resize(nInput + 1);
      53         [ +  - ]:          33 :     tx.vout[nInput].nValue = nValue;
      54                 :          33 :     tx.nLockTime = nextLockTime++;        // so all transactions get different hashes
      55   [ +  -  +  -  :          33 :     COutput output(COutPoint(tx.GetHash(), nInput), tx.vout.at(nInput), /*depth=*/ 1, /*input_bytes=*/ -1, /*spendable=*/ true, /*solvable=*/ true, /*safe=*/ true, /*time=*/ 0, /*from_me=*/ false, /*fees=*/ 0);
                   +  - ]
      56         [ +  - ]:          33 :     OutputGroup group;
      57   [ +  -  +  - ]:          33 :     group.Insert(std::make_shared<COutput>(output), /*ancestors=*/ 0, /*descendants=*/ 0);
      58         [ +  - ]:          33 :     result.AddInput(group);
      59                 :          66 : }
      60                 :             : 
      61                 :          28 : static void add_coin(const CAmount& nValue, int nInput, SelectionResult& result, CAmount fee, CAmount long_term_fee)
      62                 :             : {
      63                 :          28 :     CMutableTransaction tx;
      64         [ +  - ]:          28 :     tx.vout.resize(nInput + 1);
      65         [ +  - ]:          28 :     tx.vout[nInput].nValue = nValue;
      66                 :          28 :     tx.nLockTime = nextLockTime++;        // so all transactions get different hashes
      67   [ +  -  +  -  :          28 :     std::shared_ptr<COutput> coin = std::make_shared<COutput>(COutPoint(tx.GetHash(), nInput), tx.vout.at(nInput), /*depth=*/ 1, /*input_bytes=*/ 148, /*spendable=*/ true, /*solvable=*/ true, /*safe=*/ true, /*time=*/ 0, /*from_me=*/ false, fee);
                   +  - ]
      68         [ +  - ]:          28 :     OutputGroup group;
      69         [ +  - ]:          28 :     group.Insert(coin, /*ancestors=*/ 0, /*descendants=*/ 0);
      70         [ +  - ]:          28 :     coin->long_term_fee = long_term_fee; // group.Insert() will modify long_term_fee, so we need to set it afterwards
      71         [ +  - ]:          28 :     result.AddInput(group);
      72         [ +  - ]:          84 : }
      73                 :             : 
      74                 :      116197 : static void add_coin(CoinsResult& available_coins, CWallet& wallet, const CAmount& nValue, CFeeRate feerate = CFeeRate(0), int nAge = 6*24, bool fIsFromMe = false, int nInput =0, bool spendable = false, int custom_size = 0)
      75                 :             : {
      76                 :      116197 :     CMutableTransaction tx;
      77                 :      116197 :     tx.nLockTime = nextLockTime++;        // so all transactions get different hashes
      78         [ +  - ]:      116197 :     tx.vout.resize(nInput + 1);
      79         [ +  + ]:      116197 :     tx.vout[nInput].nValue = nValue;
      80         [ +  + ]:      116197 :     if (spendable) {
      81   [ +  -  +  -  :        6158 :         tx.vout[nInput].scriptPubKey = GetScriptForDestination(*Assert(wallet.GetNewDestination(OutputType::BECH32, "")));
             +  -  +  - ]
      82                 :             :     }
      83         [ +  - ]:      116197 :     uint256 txid = tx.GetHash();
      84                 :             : 
      85         [ +  - ]:      116197 :     LOCK(wallet.cs_wallet);
      86   [ +  -  +  -  :      232394 :     auto ret = wallet.mapWallet.emplace(std::piecewise_construct, std::forward_as_tuple(txid), std::forward_as_tuple(MakeTransactionRef(std::move(tx)), TxStateInactive{}));
                   -  + ]
      87         [ -  + ]:      116197 :     assert(ret.second);
      88         [ +  - ]:      116197 :     CWalletTx& wtx = (*ret.first).second;
      89         [ +  - ]:      116197 :     const auto& txout = wtx.tx->vout.at(nInput);
      90   [ +  +  +  -  :      232394 :     available_coins.Add(OutputType::BECH32, {COutPoint(wtx.GetHash(), nInput), txout, nAge, custom_size == 0 ? CalculateMaximumSignedInputSize(txout, &wallet, /*coin_control=*/nullptr) : custom_size, /*spendable=*/ true, /*solvable=*/ true, /*safe=*/ true, wtx.GetTxTime(), fIsFromMe, feerate});
          +  -  +  -  +  
                -  +  - ]
      91                 :      232394 : }
      92                 :             : 
      93                 :             : // Helpers
      94                 :        5601 : std::optional<SelectionResult> KnapsackSolver(std::vector<OutputGroup>& groups, const CAmount& nTargetValue,
      95                 :             :                                               CAmount change_target, FastRandomContext& rng)
      96                 :             : {
      97                 :        5601 :     auto res{KnapsackSolver(groups, nTargetValue, change_target, rng, MAX_STANDARD_TX_WEIGHT)};
      98   [ +  +  +  - ]:       10602 :     return res ? std::optional<SelectionResult>(*res) : std::nullopt;
      99                 :        5601 : }
     100                 :             : 
     101                 :         115 : std::optional<SelectionResult> SelectCoinsBnB(std::vector<OutputGroup>& utxo_pool, const CAmount& selection_target, const CAmount& cost_of_change)
     102                 :             : {
     103                 :         115 :     auto res{SelectCoinsBnB(utxo_pool, selection_target, cost_of_change, MAX_STANDARD_TX_WEIGHT)};
     104   [ +  +  +  - ]:         124 :     return res ? std::optional<SelectionResult>(*res) : std::nullopt;
     105                 :         115 : }
     106                 :             : 
     107                 :             : /** Check if SelectionResult a is equivalent to SelectionResult b.
     108                 :             :  * Equivalent means same input values, but maybe different inputs (i.e. same value, different prevout) */
     109                 :          14 : static bool EquivalentResult(const SelectionResult& a, const SelectionResult& b)
     110                 :             : {
     111                 :          14 :     std::vector<CAmount> a_amts;
     112                 :          14 :     std::vector<CAmount> b_amts;
     113   [ +  -  +  + ]:          47 :     for (const auto& coin : a.GetInputSet()) {
     114         [ +  - ]:          33 :         a_amts.push_back(coin->txout.nValue);
     115                 :             :     }
     116   [ +  -  +  + ]:          47 :     for (const auto& coin : b.GetInputSet()) {
     117         [ +  - ]:          33 :         b_amts.push_back(coin->txout.nValue);
     118                 :             :     }
     119                 :          14 :     std::sort(a_amts.begin(), a_amts.end());
     120                 :          14 :     std::sort(b_amts.begin(), b_amts.end());
     121                 :             : 
     122                 :          14 :     std::pair<std::vector<CAmount>::iterator, std::vector<CAmount>::iterator> ret = std::mismatch(a_amts.begin(), a_amts.end(), b_amts.begin());
     123   [ +  -  -  + ]:          14 :     return ret.first == a_amts.end() && ret.second == b_amts.end();
     124                 :          14 : }
     125                 :             : 
     126                 :             : /** Check if this selection is equal to another one. Equal means same inputs (i.e same value and prevout) */
     127                 :        1100 : static bool EqualResult(const SelectionResult& a, const SelectionResult& b)
     128                 :             : {
     129                 :        1100 :     std::pair<CoinSet::iterator, CoinSet::iterator> ret = std::mismatch(a.GetInputSet().begin(), a.GetInputSet().end(), b.GetInputSet().begin(),
     130                 :        1100 :         [](const std::shared_ptr<COutput>& a, const std::shared_ptr<COutput>& b) {
     131         [ +  + ]:        1100 :             return a->outpoint == b->outpoint;
     132                 :             :         });
     133   [ +  +  -  + ]:        1100 :     return ret.first == a.GetInputSet().end() && ret.second == b.GetInputSet().end();
     134                 :             : }
     135                 :             : 
     136                 :           2 : static CAmount make_hard_case(int utxos, std::vector<COutput>& utxo_pool)
     137                 :             : {
     138                 :           2 :     utxo_pool.clear();
     139                 :           2 :     CAmount target = 0;
     140         [ +  + ]:          33 :     for (int i = 0; i < utxos; ++i) {
     141                 :          31 :         target += CAmount{1} << (utxos+i);
     142                 :          31 :         add_coin(CAmount{1} << (utxos+i), 2*i, utxo_pool);
     143                 :          31 :         add_coin((CAmount{1} << (utxos+i)) + (CAmount{1} << (utxos-1-i)), 2*i + 1, utxo_pool);
     144                 :             :     }
     145                 :           2 :     return target;
     146                 :             : }
     147                 :             : 
     148                 :        2316 : inline std::vector<OutputGroup>& GroupCoins(const std::vector<COutput>& available_coins, bool subtract_fee_outputs = false)
     149                 :             : {
     150   [ +  +  +  - ]:        2317 :     static std::vector<OutputGroup> static_groups;
     151                 :        2316 :     static_groups.clear();
     152         [ +  + ]:      279032 :     for (auto& coin : available_coins) {
     153                 :      276716 :         static_groups.emplace_back();
     154                 :      276716 :         OutputGroup& group = static_groups.back();
     155         [ +  - ]:      276716 :         group.Insert(std::make_shared<COutput>(coin), /*ancestors=*/ 0, /*descendants=*/ 0);
     156                 :      276716 :         group.m_subtract_fee_outputs = subtract_fee_outputs;
     157                 :             :     }
     158                 :        2316 :     return static_groups;
     159                 :             : }
     160                 :             : 
     161                 :        3401 : inline std::vector<OutputGroup>& KnapsackGroupOutputs(const CoinsResult& available_coins, CWallet& wallet, const CoinEligibilityFilter& filter)
     162                 :             : {
     163                 :        3401 :     FastRandomContext rand{};
     164         [ +  + ]:        3401 :     CoinSelectionParams coin_selection_params{
     165                 :             :         rand,
     166                 :             :         /*change_output_size=*/ 0,
     167                 :             :         /*change_spend_size=*/ 0,
     168                 :             :         /*min_change_target=*/ CENT,
     169                 :        3401 :         /*effective_feerate=*/ CFeeRate(0),
     170                 :        3401 :         /*long_term_feerate=*/ CFeeRate(0),
     171         [ +  + ]:        3401 :         /*discard_feerate=*/ CFeeRate(0),
     172                 :             :         /*tx_noinputs_size=*/ 0,
     173                 :             :         /*avoid_partial=*/ false,
     174                 :        3401 :     };
     175   [ +  +  +  - ]:        3401 :     static OutputGroupTypeMap static_groups;
     176   [ +  -  +  -  :        6802 :     static_groups = GroupOutputs(wallet, available_coins, coin_selection_params, {{filter}})[filter];
             +  -  +  - ]
     177                 :        3401 :     return static_groups.all_groups.mixed_group;
     178                 :        3401 : }
     179                 :             : 
     180                 :          24 : static std::unique_ptr<CWallet> NewWallet(const node::NodeContext& m_node, const std::string& wallet_name = "")
     181                 :             : {
     182   [ +  -  +  - ]:          24 :     std::unique_ptr<CWallet> wallet = std::make_unique<CWallet>(m_node.chain.get(), wallet_name, CreateMockableWalletDatabase());
     183   [ +  -  +  -  :          48 :     BOOST_CHECK(wallet->LoadWallet() == DBErrors::LOAD_OK);
             +  -  +  - ]
     184         [ +  - ]:          24 :     LOCK(wallet->cs_wallet);
     185         [ +  - ]:          24 :     wallet->SetWalletFlag(WALLET_FLAG_DESCRIPTORS);
     186         [ +  - ]:          24 :     wallet->SetupDescriptorScriptPubKeyMans();
     187         [ +  - ]:          24 :     return wallet;
     188                 :          24 : }
     189                 :             : 
     190                 :             : // Branch and bound coin selection tests
     191   [ +  -  +  -  :           7 : BOOST_AUTO_TEST_CASE(bnb_search_test)
          +  -  +  -  +  
          -  +  -  +  -  
          +  -  +  -  +  
          -  +  -  +  -  
          +  -  +  -  +  
          -  +  -  +  -  
          +  -  +  -  +  
          -  +  -  +  -  
          +  -  +  -  +  
          -  +  -  +  -  
          +  -  +  -  +  
                      - ]
     192                 :             : {
     193                 :           1 :     FastRandomContext rand{};
     194                 :             :     // Setup
     195                 :           1 :     std::vector<COutput> utxo_pool;
     196         [ +  - ]:           1 :     SelectionResult expected_result(CAmount(0), SelectionAlgorithm::BNB);
     197                 :             : 
     198                 :             :     /////////////////////////
     199                 :             :     // Known Outcome tests //
     200                 :             :     /////////////////////////
     201                 :             : 
     202                 :             :     // Empty utxo pool
     203   [ +  -  +  -  :           2 :     BOOST_CHECK(!SelectCoinsBnB(GroupCoins(utxo_pool), 1 * CENT, 0.5 * CENT));
          +  -  +  -  +  
                      - ]
     204                 :             : 
     205                 :             :     // Add utxos
     206         [ +  - ]:           1 :     add_coin(1 * CENT, 1, utxo_pool);
     207         [ +  - ]:           1 :     add_coin(2 * CENT, 2, utxo_pool);
     208         [ +  - ]:           1 :     add_coin(3 * CENT, 3, utxo_pool);
     209         [ +  - ]:           1 :     add_coin(4 * CENT, 4, utxo_pool);
     210                 :             : 
     211                 :             :     // Select 1 Cent
     212         [ +  - ]:           1 :     add_coin(1 * CENT, 1, expected_result);
     213   [ +  -  +  - ]:           1 :     const auto result1 = SelectCoinsBnB(GroupCoins(utxo_pool), 1 * CENT, 0.5 * CENT);
     214   [ +  -  +  -  :           2 :     BOOST_CHECK(result1);
                   +  - ]
     215   [ +  -  +  -  :           2 :     BOOST_CHECK(EquivalentResult(expected_result, *result1));
             +  -  +  - ]
     216   [ +  -  +  -  :           1 :     BOOST_CHECK_EQUAL(result1->GetSelectedValue(), 1 * CENT);
                   +  - ]
     217         [ +  - ]:           1 :     expected_result.Clear();
     218                 :             : 
     219                 :             :     // Select 2 Cent
     220         [ +  - ]:           1 :     add_coin(2 * CENT, 2, expected_result);
     221   [ +  -  +  - ]:           1 :     const auto result2 = SelectCoinsBnB(GroupCoins(utxo_pool), 2 * CENT, 0.5 * CENT);
     222   [ +  -  +  -  :           2 :     BOOST_CHECK(result2);
                   +  - ]
     223   [ +  -  +  -  :           2 :     BOOST_CHECK(EquivalentResult(expected_result, *result2));
             +  -  +  - ]
     224   [ +  -  +  -  :           1 :     BOOST_CHECK_EQUAL(result2->GetSelectedValue(), 2 * CENT);
                   +  - ]
     225         [ +  - ]:           1 :     expected_result.Clear();
     226                 :             : 
     227                 :             :     // Select 5 Cent
     228         [ +  - ]:           1 :     add_coin(3 * CENT, 3, expected_result);
     229         [ +  - ]:           1 :     add_coin(2 * CENT, 2, expected_result);
     230   [ +  -  +  - ]:           1 :     const auto result3 = SelectCoinsBnB(GroupCoins(utxo_pool), 5 * CENT, 0.5 * CENT);
     231   [ +  -  +  -  :           2 :     BOOST_CHECK(result3);
                   +  - ]
     232   [ +  -  +  -  :           2 :     BOOST_CHECK(EquivalentResult(expected_result, *result3));
             +  -  +  - ]
     233   [ +  -  +  -  :           1 :     BOOST_CHECK_EQUAL(result3->GetSelectedValue(), 5 * CENT);
                   +  - ]
     234         [ +  - ]:           1 :     expected_result.Clear();
     235                 :             : 
     236                 :             :     // Select 11 Cent, not possible
     237   [ +  -  +  -  :           2 :     BOOST_CHECK(!SelectCoinsBnB(GroupCoins(utxo_pool), 11 * CENT, 0.5 * CENT));
          +  -  +  -  +  
                      - ]
     238         [ +  - ]:           1 :     expected_result.Clear();
     239                 :             : 
     240                 :             :     // Cost of change is greater than the difference between target value and utxo sum
     241         [ +  - ]:           1 :     add_coin(1 * CENT, 1, expected_result);
     242   [ +  -  +  - ]:           1 :     const auto result4 = SelectCoinsBnB(GroupCoins(utxo_pool), 0.9 * CENT, 0.5 * CENT);
     243   [ +  -  +  -  :           2 :     BOOST_CHECK(result4);
                   +  - ]
     244   [ +  -  +  -  :           1 :     BOOST_CHECK_EQUAL(result4->GetSelectedValue(), 1 * CENT);
                   +  - ]
     245   [ +  -  +  -  :           2 :     BOOST_CHECK(EquivalentResult(expected_result, *result4));
             +  -  +  - ]
     246         [ +  - ]:           1 :     expected_result.Clear();
     247                 :             : 
     248                 :             :     // Cost of change is less than the difference between target value and utxo sum
     249   [ +  -  +  -  :           2 :     BOOST_CHECK(!SelectCoinsBnB(GroupCoins(utxo_pool), 0.9 * CENT, 0));
          +  -  +  -  +  
                      - ]
     250         [ +  - ]:           1 :     expected_result.Clear();
     251                 :             : 
     252                 :             :     // Select 10 Cent
     253         [ +  - ]:           1 :     add_coin(5 * CENT, 5, utxo_pool);
     254         [ +  - ]:           1 :     add_coin(4 * CENT, 4, expected_result);
     255         [ +  - ]:           1 :     add_coin(3 * CENT, 3, expected_result);
     256         [ +  - ]:           1 :     add_coin(2 * CENT, 2, expected_result);
     257         [ +  - ]:           1 :     add_coin(1 * CENT, 1, expected_result);
     258   [ +  -  +  - ]:           1 :     const auto result5 = SelectCoinsBnB(GroupCoins(utxo_pool), 10 * CENT, 0.5 * CENT);
     259   [ +  -  +  -  :           2 :     BOOST_CHECK(result5);
                   +  - ]
     260   [ +  -  +  -  :           2 :     BOOST_CHECK(EquivalentResult(expected_result, *result5));
             +  -  +  - ]
     261   [ +  -  +  -  :           1 :     BOOST_CHECK_EQUAL(result5->GetSelectedValue(), 10 * CENT);
                   +  - ]
     262         [ +  - ]:           1 :     expected_result.Clear();
     263                 :             : 
     264                 :             :     // Select 0.25 Cent, not possible
     265   [ +  -  +  -  :           2 :     BOOST_CHECK(!SelectCoinsBnB(GroupCoins(utxo_pool), 0.25 * CENT, 0.5 * CENT));
          +  -  +  -  +  
                      - ]
     266         [ +  - ]:           1 :     expected_result.Clear();
     267                 :             : 
     268                 :             :     // Iteration exhaustion test
     269         [ +  - ]:           1 :     CAmount target = make_hard_case(17, utxo_pool);
     270   [ +  -  +  -  :           2 :     BOOST_CHECK(!SelectCoinsBnB(GroupCoins(utxo_pool), target, 1)); // Should exhaust
          +  -  +  -  +  
                      - ]
     271         [ +  - ]:           1 :     target = make_hard_case(14, utxo_pool);
     272   [ +  -  +  - ]:           1 :     const auto result7 = SelectCoinsBnB(GroupCoins(utxo_pool), target, 1); // Should not exhaust
     273   [ +  -  +  - ]:           2 :     BOOST_CHECK(result7);
     274                 :             : 
     275                 :             :     // Test same value early bailout optimization
     276                 :           1 :     utxo_pool.clear();
     277         [ +  - ]:           1 :     add_coin(7 * CENT, 7, expected_result);
     278         [ +  - ]:           1 :     add_coin(7 * CENT, 7, expected_result);
     279         [ +  - ]:           1 :     add_coin(7 * CENT, 7, expected_result);
     280         [ +  - ]:           1 :     add_coin(7 * CENT, 7, expected_result);
     281         [ +  - ]:           1 :     add_coin(2 * CENT, 7, expected_result);
     282         [ +  - ]:           1 :     add_coin(7 * CENT, 7, utxo_pool);
     283         [ +  - ]:           1 :     add_coin(7 * CENT, 7, utxo_pool);
     284         [ +  - ]:           1 :     add_coin(7 * CENT, 7, utxo_pool);
     285         [ +  - ]:           1 :     add_coin(7 * CENT, 7, utxo_pool);
     286         [ +  - ]:           1 :     add_coin(2 * CENT, 7, utxo_pool);
     287         [ +  + ]:       50001 :     for (int i = 0; i < 50000; ++i) {
     288         [ +  - ]:       50000 :         add_coin(5 * CENT, 7, utxo_pool);
     289                 :             :     }
     290   [ +  -  +  - ]:           1 :     const auto result8 = SelectCoinsBnB(GroupCoins(utxo_pool), 30 * CENT, 5000);
     291   [ +  -  +  -  :           2 :     BOOST_CHECK(result8);
                   +  - ]
     292   [ +  -  +  -  :           1 :     BOOST_CHECK_EQUAL(result8->GetSelectedValue(), 30 * CENT);
                   +  - ]
     293   [ +  -  +  -  :           2 :     BOOST_CHECK(EquivalentResult(expected_result, *result8));
                   +  - ]
     294                 :             : 
     295                 :             :     ////////////////////
     296                 :             :     // Behavior tests //
     297                 :             :     ////////////////////
     298                 :             :     // Select 1 Cent with pool of only greater than 5 Cent
     299                 :           1 :     utxo_pool.clear();
     300         [ +  + ]:          17 :     for (int i = 5; i <= 20; ++i) {
     301         [ +  - ]:          16 :         add_coin(i * CENT, i, utxo_pool);
     302                 :             :     }
     303                 :             :     // Run 100 times, to make sure it is never finding a solution
     304         [ +  + ]:         101 :     for (int i = 0; i < 100; ++i) {
     305   [ +  -  +  -  :         200 :         BOOST_CHECK(!SelectCoinsBnB(GroupCoins(utxo_pool), 1 * CENT, 2 * CENT));
             +  -  +  - ]
     306                 :             :     }
     307                 :             : 
     308                 :             :     // Make sure that effective value is working in AttemptSelection when BnB is used
     309         [ +  - ]:           1 :     CoinSelectionParams coin_selection_params_bnb{
     310                 :             :         rand,
     311                 :             :         /*change_output_size=*/ 31,
     312                 :             :         /*change_spend_size=*/ 68,
     313                 :             :         /*min_change_target=*/ 0,
     314                 :           1 :         /*effective_feerate=*/ CFeeRate(3000),
     315                 :           1 :         /*long_term_feerate=*/ CFeeRate(1000),
     316         [ +  - ]:           1 :         /*discard_feerate=*/ CFeeRate(1000),
     317                 :             :         /*tx_noinputs_size=*/ 0,
     318                 :             :         /*avoid_partial=*/ false,
     319                 :           1 :     };
     320         [ +  - ]:           1 :     coin_selection_params_bnb.m_change_fee = coin_selection_params_bnb.m_effective_feerate.GetFee(coin_selection_params_bnb.change_output_size);
     321         [ +  - ]:           1 :     coin_selection_params_bnb.m_cost_of_change = coin_selection_params_bnb.m_effective_feerate.GetFee(coin_selection_params_bnb.change_spend_size) + coin_selection_params_bnb.m_change_fee;
     322         [ +  - ]:           1 :     coin_selection_params_bnb.min_viable_change = coin_selection_params_bnb.m_effective_feerate.GetFee(coin_selection_params_bnb.change_spend_size);
     323                 :             : 
     324                 :           1 :     {
     325   [ +  -  +  - ]:           1 :         std::unique_ptr<CWallet> wallet = NewWallet(m_node);
     326                 :             : 
     327         [ +  - ]:           1 :         CoinsResult available_coins;
     328                 :             : 
     329         [ +  - ]:           1 :         add_coin(available_coins, *wallet, 1, coin_selection_params_bnb.m_effective_feerate);
     330         [ +  - ]:           2 :         available_coins.All().at(0).input_bytes = 40; // Make sure that it has a negative effective value. The next check should assert if this somehow got through. Otherwise it will fail
     331   [ +  -  +  -  :           2 :         BOOST_CHECK(!SelectCoinsBnB(GroupCoins(available_coins.All()), 1 * CENT, coin_selection_params_bnb.m_cost_of_change));
          +  -  +  -  +  
                -  +  - ]
     332                 :             : 
     333                 :             :         // Test fees subtracted from output:
     334         [ +  - ]:           1 :         available_coins.Clear();
     335         [ +  - ]:           1 :         add_coin(available_coins, *wallet, 1 * CENT, coin_selection_params_bnb.m_effective_feerate);
     336         [ +  - ]:           2 :         available_coins.All().at(0).input_bytes = 40;
     337   [ +  -  +  -  :           1 :         const auto result9 = SelectCoinsBnB(GroupCoins(available_coins.All()), 1 * CENT, coin_selection_params_bnb.m_cost_of_change);
                   +  - ]
     338   [ +  -  +  -  :           2 :         BOOST_CHECK(result9);
                   +  - ]
     339   [ +  -  +  -  :           1 :         BOOST_CHECK_EQUAL(result9->GetSelectedValue(), 1 * CENT);
                   +  - ]
     340         [ +  - ]:           1 :     }
     341                 :             : 
     342                 :           1 :     {
     343   [ +  -  +  - ]:           1 :         std::unique_ptr<CWallet> wallet = NewWallet(m_node);
     344                 :             : 
     345         [ +  - ]:           1 :         CoinsResult available_coins;
     346                 :             : 
     347         [ +  - ]:           1 :         coin_selection_params_bnb.m_effective_feerate = CFeeRate(0);
     348         [ +  - ]:           1 :         add_coin(available_coins, *wallet, 5 * CENT, coin_selection_params_bnb.m_effective_feerate, 6 * 24, false, 0, true);
     349         [ +  - ]:           1 :         add_coin(available_coins, *wallet, 3 * CENT, coin_selection_params_bnb.m_effective_feerate, 6 * 24, false, 0, true);
     350         [ +  - ]:           1 :         add_coin(available_coins, *wallet, 2 * CENT, coin_selection_params_bnb.m_effective_feerate, 6 * 24, false, 0, true);
     351         [ +  - ]:           1 :         CCoinControl coin_control;
     352                 :           1 :         coin_control.m_allow_other_inputs = true;
     353         [ +  - ]:           2 :         COutput select_coin = available_coins.All().at(0);
     354         [ +  - ]:           1 :         coin_control.Select(select_coin.outpoint);
     355         [ +  - ]:           1 :         PreSelectedInputs selected_input;
     356         [ +  - ]:           1 :         selected_input.Insert(select_coin, coin_selection_params_bnb.m_subtract_fee_outputs);
     357   [ +  -  +  -  :           3 :         available_coins.Erase({available_coins.coins[OutputType::BECH32].begin()->outpoint});
             +  -  +  - ]
     358                 :             : 
     359         [ +  - ]:           1 :         LOCK(wallet->cs_wallet);
     360         [ +  - ]:           1 :         const auto result10 = SelectCoins(*wallet, available_coins, selected_input, 10 * CENT, coin_control, coin_selection_params_bnb);
     361   [ +  -  +  - ]:           2 :         BOOST_CHECK(result10);
     362   [ +  -  +  - ]:           2 :     }
     363                 :           1 :     {
     364   [ +  -  +  - ]:           1 :         std::unique_ptr<CWallet> wallet = NewWallet(m_node);
     365         [ +  - ]:           1 :         LOCK(wallet->cs_wallet); // Every 'SelectCoins' call requires it
     366                 :             : 
     367         [ +  - ]:           1 :         CoinsResult available_coins;
     368                 :             : 
     369                 :             :         // single coin should be selected when effective fee > long term fee
     370         [ +  - ]:           1 :         coin_selection_params_bnb.m_effective_feerate = CFeeRate(5000);
     371                 :           1 :         coin_selection_params_bnb.m_long_term_feerate = CFeeRate(3000);
     372                 :             : 
     373                 :             :         // Add selectable outputs, increasing their raw amounts by their input fee to make the effective value equal to the raw amount
     374         [ +  - ]:           1 :         CAmount input_fee = coin_selection_params_bnb.m_effective_feerate.GetFee(/*num_bytes=*/68); // bech32 input size (default test output type)
     375         [ +  - ]:           1 :         add_coin(available_coins, *wallet, 10 * CENT + input_fee, coin_selection_params_bnb.m_effective_feerate, 6 * 24, false, 0, true);
     376         [ +  - ]:           1 :         add_coin(available_coins, *wallet, 9 * CENT + input_fee, coin_selection_params_bnb.m_effective_feerate, 6 * 24, false, 0, true);
     377         [ +  - ]:           1 :         add_coin(available_coins, *wallet, 1 * CENT + input_fee, coin_selection_params_bnb.m_effective_feerate, 6 * 24, false, 0, true);
     378                 :             : 
     379         [ +  - ]:           1 :         expected_result.Clear();
     380         [ +  - ]:           1 :         add_coin(10 * CENT + input_fee, 2, expected_result);
     381         [ +  - ]:           1 :         CCoinControl coin_control;
     382                 :           0 :         const auto result11 = SelectCoins(*wallet, available_coins, /*pre_set_inputs=*/{}, 10 * CENT, coin_control, coin_selection_params_bnb);
     383   [ +  -  +  -  :           2 :         BOOST_CHECK(EquivalentResult(expected_result, *result11));
             +  -  +  - ]
     384         [ +  - ]:           1 :         available_coins.Clear();
     385                 :             : 
     386                 :             :         // more coins should be selected when effective fee < long term fee
     387         [ +  - ]:           1 :         coin_selection_params_bnb.m_effective_feerate = CFeeRate(3000);
     388                 :           1 :         coin_selection_params_bnb.m_long_term_feerate = CFeeRate(5000);
     389                 :             : 
     390                 :             :         // Add selectable outputs, increasing their raw amounts by their input fee to make the effective value equal to the raw amount
     391         [ +  - ]:           1 :         input_fee = coin_selection_params_bnb.m_effective_feerate.GetFee(/*num_bytes=*/68); // bech32 input size (default test output type)
     392         [ +  - ]:           1 :         add_coin(available_coins, *wallet, 10 * CENT + input_fee, coin_selection_params_bnb.m_effective_feerate, 6 * 24, false, 0, true);
     393         [ +  - ]:           1 :         add_coin(available_coins, *wallet, 9 * CENT + input_fee, coin_selection_params_bnb.m_effective_feerate, 6 * 24, false, 0, true);
     394         [ +  - ]:           1 :         add_coin(available_coins, *wallet, 1 * CENT + input_fee, coin_selection_params_bnb.m_effective_feerate, 6 * 24, false, 0, true);
     395                 :             : 
     396         [ +  - ]:           1 :         expected_result.Clear();
     397         [ +  - ]:           1 :         add_coin(9 * CENT + input_fee, 2, expected_result);
     398         [ +  - ]:           1 :         add_coin(1 * CENT + input_fee, 2, expected_result);
     399                 :           0 :         const auto result12 = SelectCoins(*wallet, available_coins, /*pre_set_inputs=*/{}, 10 * CENT, coin_control, coin_selection_params_bnb);
     400   [ +  -  +  -  :           2 :         BOOST_CHECK(EquivalentResult(expected_result, *result12));
             +  -  +  - ]
     401         [ +  - ]:           1 :         available_coins.Clear();
     402                 :             : 
     403                 :             :         // pre selected coin should be selected even if disadvantageous
     404         [ +  - ]:           1 :         coin_selection_params_bnb.m_effective_feerate = CFeeRate(5000);
     405                 :           1 :         coin_selection_params_bnb.m_long_term_feerate = CFeeRate(3000);
     406                 :             : 
     407                 :             :         // Add selectable outputs, increasing their raw amounts by their input fee to make the effective value equal to the raw amount
     408         [ +  - ]:           1 :         input_fee = coin_selection_params_bnb.m_effective_feerate.GetFee(/*num_bytes=*/68); // bech32 input size (default test output type)
     409         [ +  - ]:           1 :         add_coin(available_coins, *wallet, 10 * CENT + input_fee, coin_selection_params_bnb.m_effective_feerate, 6 * 24, false, 0, true);
     410         [ +  - ]:           1 :         add_coin(available_coins, *wallet, 9 * CENT + input_fee, coin_selection_params_bnb.m_effective_feerate, 6 * 24, false, 0, true);
     411         [ +  - ]:           1 :         add_coin(available_coins, *wallet, 1 * CENT + input_fee, coin_selection_params_bnb.m_effective_feerate, 6 * 24, false, 0, true);
     412                 :             : 
     413         [ +  - ]:           1 :         expected_result.Clear();
     414         [ +  - ]:           1 :         add_coin(9 * CENT + input_fee, 2, expected_result);
     415         [ +  - ]:           1 :         add_coin(1 * CENT + input_fee, 2, expected_result);
     416                 :           1 :         coin_control.m_allow_other_inputs = true;
     417         [ +  - ]:           2 :         COutput select_coin = available_coins.All().at(1); // pre select 9 coin
     418         [ +  - ]:           1 :         coin_control.Select(select_coin.outpoint);
     419         [ +  - ]:           1 :         PreSelectedInputs selected_input;
     420         [ +  - ]:           1 :         selected_input.Insert(select_coin, coin_selection_params_bnb.m_subtract_fee_outputs);
     421   [ +  -  +  -  :           3 :         available_coins.Erase({(++available_coins.coins[OutputType::BECH32].begin())->outpoint});
             +  -  +  - ]
     422         [ +  - ]:           1 :         const auto result13 = SelectCoins(*wallet, available_coins, selected_input, 10 * CENT, coin_control, coin_selection_params_bnb);
     423   [ +  -  +  -  :           2 :         BOOST_CHECK(EquivalentResult(expected_result, *result13));
                   +  - ]
     424   [ +  -  +  - ]:           2 :     }
     425                 :             : 
     426                 :           1 :     {
     427                 :             :         // Test bnb max weight exceeded
     428                 :             :         // Inputs set [10, 9, 8, 5, 3, 1], Selection Target = 16 and coin 5 exceeding the max weight.
     429                 :             : 
     430   [ +  -  +  - ]:           1 :         std::unique_ptr<CWallet> wallet = NewWallet(m_node);
     431                 :             : 
     432         [ +  - ]:           1 :         CoinsResult available_coins;
     433         [ +  - ]:           1 :         add_coin(available_coins, *wallet, 10 * CENT, coin_selection_params_bnb.m_effective_feerate, 6 * 24, false, 0, true);
     434         [ +  - ]:           1 :         add_coin(available_coins, *wallet, 9 * CENT, coin_selection_params_bnb.m_effective_feerate, 6 * 24, false, 0, true);
     435         [ +  - ]:           1 :         add_coin(available_coins, *wallet, 8 * CENT, coin_selection_params_bnb.m_effective_feerate, 6 * 24, false, 0, true);
     436         [ +  - ]:           1 :         add_coin(available_coins, *wallet, 5 * CENT, coin_selection_params_bnb.m_effective_feerate, 6 * 24, false, 0, true, /*custom_size=*/MAX_STANDARD_TX_WEIGHT);
     437         [ +  - ]:           1 :         add_coin(available_coins, *wallet, 3 * CENT, coin_selection_params_bnb.m_effective_feerate, 6 * 24, false, 0, true);
     438         [ +  - ]:           1 :         add_coin(available_coins, *wallet, 1 * CENT, coin_selection_params_bnb.m_effective_feerate, 6 * 24, false, 0, true);
     439                 :             : 
     440                 :           1 :         CAmount selection_target = 16 * CENT;
     441                 :           0 :         const auto& no_res = SelectCoinsBnB(GroupCoins(available_coins.All(), /*subtract_fee_outputs*/true),
     442   [ +  -  +  -  :           1 :                                             selection_target, /*cost_of_change=*/0, MAX_STANDARD_TX_WEIGHT);
                   +  - ]
     443   [ +  -  +  -  :           2 :         BOOST_REQUIRE(!no_res);
                   +  - ]
     444   [ +  -  +  -  :           3 :         BOOST_CHECK(util::ErrorString(no_res).original.find("The inputs size exceeds the maximum weight") != std::string::npos);
             +  -  +  - ]
     445                 :             : 
     446                 :             :         // Now add same coin value with a good size and check that it gets selected
     447         [ +  - ]:           1 :         add_coin(available_coins, *wallet, 5 * CENT, coin_selection_params_bnb.m_effective_feerate, 6 * 24, false, 0, true);
     448   [ +  -  +  -  :           1 :         const auto& res = SelectCoinsBnB(GroupCoins(available_coins.All(), /*subtract_fee_outputs*/true), selection_target, /*cost_of_change=*/0);
                   +  - ]
     449                 :             : 
     450         [ +  - ]:           1 :         expected_result.Clear();
     451         [ +  - ]:           1 :         add_coin(8 * CENT, 2, expected_result);
     452         [ +  - ]:           1 :         add_coin(5 * CENT, 2, expected_result);
     453         [ +  - ]:           1 :         add_coin(3 * CENT, 2, expected_result);
     454   [ +  -  +  -  :           2 :         BOOST_CHECK(EquivalentResult(expected_result, *res));
                   +  - ]
     455         [ +  - ]:           2 :     }
     456   [ +  -  +  - ]:           3 : }
     457                 :             : 
     458   [ +  -  +  -  :           7 : BOOST_AUTO_TEST_CASE(bnb_sffo_restriction)
          +  -  +  -  +  
          -  +  -  +  -  
          +  -  +  -  +  
          -  +  -  +  -  
          +  -  +  -  +  
          -  +  -  +  -  
          +  -  +  -  +  
          -  +  -  +  -  
          +  -  +  -  +  
          -  +  -  +  -  
          +  -  +  -  +  
                      - ]
     459                 :             : {
     460                 :             :     // Verify the coin selection process does not produce a BnB solution when SFFO is enabled.
     461                 :             :     // This is currently problematic because it could require a change output. And BnB is specialized on changeless solutions.
     462         [ +  - ]:           1 :     std::unique_ptr<CWallet> wallet = NewWallet(m_node);
     463         [ +  - ]:           2 :     WITH_LOCK(wallet->cs_wallet, wallet->SetLastBlockProcessed(300, uint256{})); // set a high block so internal UTXOs are selectable
     464                 :             : 
     465                 :           1 :     FastRandomContext rand{};
     466         [ +  - ]:           1 :     CoinSelectionParams params{
     467                 :             :             rand,
     468                 :             :             /*change_output_size=*/ 31,  // unused value, p2wpkh output size (wallet default change type)
     469                 :             :             /*change_spend_size=*/ 68,   // unused value, p2wpkh input size (high-r signature)
     470                 :             :             /*min_change_target=*/ 0,    // dummy, set later
     471                 :           1 :             /*effective_feerate=*/ CFeeRate(3000),
     472                 :           1 :             /*long_term_feerate=*/ CFeeRate(1000),
     473         [ +  - ]:           1 :             /*discard_feerate=*/ CFeeRate(1000),
     474                 :             :             /*tx_noinputs_size=*/ 0,
     475                 :             :             /*avoid_partial=*/ false,
     476                 :           1 :     };
     477                 :           1 :     params.m_subtract_fee_outputs = true;
     478         [ +  - ]:           1 :     params.m_change_fee = params.m_effective_feerate.GetFee(params.change_output_size);
     479         [ +  - ]:           1 :     params.m_cost_of_change = params.m_discard_feerate.GetFee(params.change_spend_size) + params.m_change_fee;
     480                 :           1 :     params.m_min_change_target = params.m_cost_of_change + 1;
     481                 :             :     // Add spendable coin at the BnB selection upper bound
     482         [ +  - ]:           1 :     CoinsResult available_coins;
     483         [ +  - ]:           1 :     add_coin(available_coins, *wallet, COIN + params.m_cost_of_change, /*feerate=*/params.m_effective_feerate, /*nAge=*/6, /*fIsFromMe=*/true, /*nInput=*/0, /*spendable=*/true);
     484         [ +  - ]:           1 :     add_coin(available_coins, *wallet, 0.5 * COIN + params.m_cost_of_change, /*feerate=*/params.m_effective_feerate, /*nAge=*/6, /*fIsFromMe=*/true, /*nInput=*/0, /*spendable=*/true);
     485         [ +  - ]:           1 :     add_coin(available_coins, *wallet, 0.5 * COIN, /*feerate=*/params.m_effective_feerate, /*nAge=*/6, /*fIsFromMe=*/true, /*nInput=*/0, /*spendable=*/true);
     486                 :             :     // Knapsack will only find a changeless solution on an exact match to the satoshi, SRD doesn’t look for changeless
     487                 :             :     // If BnB were run, it would produce a single input solution with the best waste score
     488   [ +  -  +  -  :           4 :     auto result = WITH_LOCK(wallet->cs_wallet, return SelectCoins(*wallet, available_coins, /*pre_set_inputs=*/{}, COIN, /*coin_control=*/{}, params));
                   +  - ]
     489   [ +  -  +  -  :           2 :     BOOST_CHECK(result.has_value());
                   +  - ]
     490   [ +  -  +  - ]:           1 :     BOOST_CHECK_NE(result->GetAlgo(), SelectionAlgorithm::BNB);
     491   [ +  -  +  -  :           2 :     BOOST_CHECK(result->GetInputSet().size() == 2);
             +  -  +  - ]
     492                 :             :     // We have only considered BnB, SRD, and Knapsack. Test needs to be reevaluated if new algo is added
     493   [ +  -  +  -  :           3 :     BOOST_CHECK(result->GetAlgo() == SelectionAlgorithm::SRD || result->GetAlgo() == SelectionAlgorithm::KNAPSACK);
             +  -  +  - ]
     494         [ +  - ]:           2 : }
     495                 :             : 
     496   [ +  -  +  -  :           7 : BOOST_AUTO_TEST_CASE(knapsack_solver_test)
          +  -  +  -  +  
          -  +  -  +  -  
          +  -  +  -  +  
          -  +  -  +  -  
          +  -  +  -  +  
          -  +  -  +  -  
          +  -  +  -  +  
          -  +  -  +  -  
          +  -  +  -  +  
          -  +  -  +  -  
          +  -  +  -  +  
                      - ]
     497                 :             : {
     498                 :           1 :     FastRandomContext rand{};
     499                 :        5601 :     const auto temp1{[&rand](std::vector<OutputGroup>& g, const CAmount& v, CAmount c) { return KnapsackSolver(g, v, c, rand); }};
     500                 :           1 :     const auto KnapsackSolver{temp1};
     501   [ +  -  +  - ]:           1 :     std::unique_ptr<CWallet> wallet = NewWallet(m_node);
     502                 :             : 
     503                 :           1 :     CoinsResult available_coins;
     504                 :             : 
     505                 :             :     // test multiple times to allow for differences in the shuffle order
     506         [ +  + ]:         101 :     for (int i = 0; i < RUN_TESTS; i++)
     507                 :             :     {
     508         [ +  - ]:         100 :         available_coins.Clear();
     509                 :             : 
     510                 :             :         // with an empty wallet we can't even pay one cent
     511   [ +  -  +  -  :         200 :         BOOST_CHECK(!KnapsackSolver(KnapsackGroupOutputs(available_coins, *wallet, filter_standard), 1 * CENT, CENT));
          +  -  +  -  +  
                      - ]
     512                 :             : 
     513         [ +  - ]:         100 :         add_coin(available_coins, *wallet, 1*CENT, CFeeRate(0), 4);        // add a new 1 cent coin
     514                 :             : 
     515                 :             :         // with a new 1 cent coin, we still can't find a mature 1 cent
     516   [ +  -  +  -  :         200 :         BOOST_CHECK(!KnapsackSolver(KnapsackGroupOutputs(available_coins, *wallet, filter_standard), 1 * CENT, CENT));
          +  -  +  -  +  
                      - ]
     517                 :             : 
     518                 :             :         // but we can find a new 1 cent
     519   [ +  -  +  - ]:         100 :         const auto result1 = KnapsackSolver(KnapsackGroupOutputs(available_coins, *wallet, filter_confirmed), 1 * CENT, CENT);
     520   [ +  -  +  -  :         200 :         BOOST_CHECK(result1);
                   +  - ]
     521   [ +  -  +  -  :         100 :         BOOST_CHECK_EQUAL(result1->GetSelectedValue(), 1 * CENT);
                   +  - ]
     522                 :             : 
     523         [ +  - ]:         100 :         add_coin(available_coins, *wallet, 2*CENT);           // add a mature 2 cent coin
     524                 :             : 
     525                 :             :         // we can't make 3 cents of mature coins
     526   [ +  -  +  -  :         200 :         BOOST_CHECK(!KnapsackSolver(KnapsackGroupOutputs(available_coins, *wallet, filter_standard), 3 * CENT, CENT));
          +  -  +  -  +  
                      - ]
     527                 :             : 
     528                 :             :         // we can make 3 cents of new coins
     529   [ +  -  +  - ]:         100 :         const auto result2 = KnapsackSolver(KnapsackGroupOutputs(available_coins, *wallet, filter_confirmed), 3 * CENT, CENT);
     530   [ +  -  +  -  :         200 :         BOOST_CHECK(result2);
                   +  - ]
     531   [ +  -  +  -  :         100 :         BOOST_CHECK_EQUAL(result2->GetSelectedValue(), 3 * CENT);
                   +  - ]
     532                 :             : 
     533         [ +  - ]:         100 :         add_coin(available_coins, *wallet, 5*CENT);           // add a mature 5 cent coin,
     534         [ +  - ]:         100 :         add_coin(available_coins, *wallet, 10*CENT, CFeeRate(0), 3, true); // a new 10 cent coin sent from one of our own addresses
     535         [ +  - ]:         100 :         add_coin(available_coins, *wallet, 20*CENT);          // and a mature 20 cent coin
     536                 :             : 
     537                 :             :         // now we have new: 1+10=11 (of which 10 was self-sent), and mature: 2+5+20=27.  total = 38
     538                 :             : 
     539                 :             :         // we can't make 38 cents only if we disallow new coins:
     540   [ +  -  +  -  :         200 :         BOOST_CHECK(!KnapsackSolver(KnapsackGroupOutputs(available_coins, *wallet, filter_standard), 38 * CENT, CENT));
          +  -  +  -  +  
                      - ]
     541                 :             :         // we can't even make 37 cents if we don't allow new coins even if they're from us
     542   [ +  -  +  -  :         200 :         BOOST_CHECK(!KnapsackSolver(KnapsackGroupOutputs(available_coins, *wallet, filter_standard_extra), 38 * CENT, CENT));
          +  -  +  -  +  
                      - ]
     543                 :             :         // but we can make 37 cents if we accept new coins from ourself
     544   [ +  -  +  - ]:         100 :         const auto result3 = KnapsackSolver(KnapsackGroupOutputs(available_coins, *wallet, filter_standard), 37 * CENT, CENT);
     545   [ +  -  +  -  :         200 :         BOOST_CHECK(result3);
                   +  - ]
     546   [ +  -  +  -  :         100 :         BOOST_CHECK_EQUAL(result3->GetSelectedValue(), 37 * CENT);
                   +  - ]
     547                 :             :         // and we can make 38 cents if we accept all new coins
     548   [ +  -  +  - ]:         100 :         const auto result4 = KnapsackSolver(KnapsackGroupOutputs(available_coins, *wallet, filter_confirmed), 38 * CENT, CENT);
     549   [ +  -  +  -  :         200 :         BOOST_CHECK(result4);
                   +  - ]
     550   [ +  -  +  -  :         100 :         BOOST_CHECK_EQUAL(result4->GetSelectedValue(), 38 * CENT);
                   +  - ]
     551                 :             : 
     552                 :             :         // try making 34 cents from 1,2,5,10,20 - we can't do it exactly
     553   [ +  -  +  - ]:         100 :         const auto result5 = KnapsackSolver(KnapsackGroupOutputs(available_coins, *wallet, filter_confirmed), 34 * CENT, CENT);
     554   [ +  -  +  -  :         200 :         BOOST_CHECK(result5);
                   +  - ]
     555   [ +  -  +  -  :         100 :         BOOST_CHECK_EQUAL(result5->GetSelectedValue(), 35 * CENT);       // but 35 cents is closest
                   +  - ]
     556   [ +  -  +  -  :         100 :         BOOST_CHECK_EQUAL(result5->GetInputSet().size(), 3U);     // the best should be 20+10+5.  it's incredibly unlikely the 1 or 2 got included (but possible)
                   +  - ]
     557                 :             : 
     558                 :             :         // when we try making 7 cents, the smaller coins (1,2,5) are enough.  We should see just 2+5
     559   [ +  -  +  - ]:         100 :         const auto result6 = KnapsackSolver(KnapsackGroupOutputs(available_coins, *wallet, filter_confirmed), 7 * CENT, CENT);
     560   [ +  -  +  -  :         200 :         BOOST_CHECK(result6);
                   +  - ]
     561   [ +  -  +  -  :         100 :         BOOST_CHECK_EQUAL(result6->GetSelectedValue(), 7 * CENT);
                   +  - ]
     562   [ +  -  +  -  :         100 :         BOOST_CHECK_EQUAL(result6->GetInputSet().size(), 2U);
                   +  - ]
     563                 :             : 
     564                 :             :         // when we try making 8 cents, the smaller coins (1,2,5) are exactly enough.
     565   [ +  -  +  - ]:         100 :         const auto result7 = KnapsackSolver(KnapsackGroupOutputs(available_coins, *wallet, filter_confirmed), 8 * CENT, CENT);
     566   [ +  -  +  -  :         200 :         BOOST_CHECK(result7);
                   +  - ]
     567   [ +  -  +  -  :         200 :         BOOST_CHECK(result7->GetSelectedValue() == 8 * CENT);
             +  -  +  - ]
     568   [ +  -  +  -  :         100 :         BOOST_CHECK_EQUAL(result7->GetInputSet().size(), 3U);
                   +  - ]
     569                 :             : 
     570                 :             :         // when we try making 9 cents, no subset of smaller coins is enough, and we get the next bigger coin (10)
     571   [ +  -  +  - ]:         100 :         const auto result8 = KnapsackSolver(KnapsackGroupOutputs(available_coins, *wallet, filter_confirmed), 9 * CENT, CENT);
     572   [ +  -  +  -  :         200 :         BOOST_CHECK(result8);
                   +  - ]
     573   [ +  -  +  -  :         100 :         BOOST_CHECK_EQUAL(result8->GetSelectedValue(), 10 * CENT);
                   +  - ]
     574   [ +  -  +  -  :         100 :         BOOST_CHECK_EQUAL(result8->GetInputSet().size(), 1U);
                   +  - ]
     575                 :             : 
     576                 :             :         // now clear out the wallet and start again to test choosing between subsets of smaller coins and the next biggest coin
     577         [ +  - ]:         100 :         available_coins.Clear();
     578                 :             : 
     579         [ +  - ]:         100 :         add_coin(available_coins, *wallet,  6*CENT);
     580         [ +  - ]:         100 :         add_coin(available_coins, *wallet,  7*CENT);
     581         [ +  - ]:         100 :         add_coin(available_coins, *wallet,  8*CENT);
     582         [ +  - ]:         100 :         add_coin(available_coins, *wallet, 20*CENT);
     583         [ +  - ]:         100 :         add_coin(available_coins, *wallet, 30*CENT); // now we have 6+7+8+20+30 = 71 cents total
     584                 :             : 
     585                 :             :         // check that we have 71 and not 72
     586   [ +  -  +  - ]:         100 :         const auto result9 = KnapsackSolver(KnapsackGroupOutputs(available_coins, *wallet, filter_confirmed), 71 * CENT, CENT);
     587   [ +  -  +  -  :         200 :         BOOST_CHECK(result9);
                   +  - ]
     588   [ +  -  +  -  :         200 :         BOOST_CHECK(!KnapsackSolver(KnapsackGroupOutputs(available_coins, *wallet, filter_confirmed), 72 * CENT, CENT));
          +  -  +  -  +  
                      - ]
     589                 :             : 
     590                 :             :         // now try making 16 cents.  the best smaller coins can do is 6+7+8 = 21; not as good at the next biggest coin, 20
     591   [ +  -  +  - ]:         100 :         const auto result10 = KnapsackSolver(KnapsackGroupOutputs(available_coins, *wallet, filter_confirmed), 16 * CENT, CENT);
     592   [ +  -  +  -  :         200 :         BOOST_CHECK(result10);
                   +  - ]
     593   [ +  -  +  -  :         100 :         BOOST_CHECK_EQUAL(result10->GetSelectedValue(), 20 * CENT); // we should get 20 in one coin
                   +  - ]
     594   [ +  -  +  -  :         100 :         BOOST_CHECK_EQUAL(result10->GetInputSet().size(), 1U);
                   +  - ]
     595                 :             : 
     596         [ +  - ]:         100 :         add_coin(available_coins, *wallet,  5*CENT); // now we have 5+6+7+8+20+30 = 75 cents total
     597                 :             : 
     598                 :             :         // now if we try making 16 cents again, the smaller coins can make 5+6+7 = 18 cents, better than the next biggest coin, 20
     599   [ +  -  +  - ]:         100 :         const auto result11 = KnapsackSolver(KnapsackGroupOutputs(available_coins, *wallet, filter_confirmed), 16 * CENT, CENT);
     600   [ +  -  +  -  :         200 :         BOOST_CHECK(result11);
                   +  - ]
     601   [ +  -  +  -  :         100 :         BOOST_CHECK_EQUAL(result11->GetSelectedValue(), 18 * CENT); // we should get 18 in 3 coins
                   +  - ]
     602   [ +  -  +  -  :         100 :         BOOST_CHECK_EQUAL(result11->GetInputSet().size(), 3U);
                   +  - ]
     603                 :             : 
     604         [ +  - ]:         100 :         add_coin(available_coins, *wallet,  18*CENT); // now we have 5+6+7+8+18+20+30
     605                 :             : 
     606                 :             :         // and now if we try making 16 cents again, the smaller coins can make 5+6+7 = 18 cents, the same as the next biggest coin, 18
     607   [ +  -  +  - ]:         100 :         const auto result12 = KnapsackSolver(KnapsackGroupOutputs(available_coins, *wallet, filter_confirmed), 16 * CENT, CENT);
     608   [ +  -  +  -  :         200 :         BOOST_CHECK(result12);
                   +  - ]
     609   [ +  -  +  -  :         100 :         BOOST_CHECK_EQUAL(result12->GetSelectedValue(), 18 * CENT);  // we should get 18 in 1 coin
                   +  - ]
     610   [ +  -  +  -  :         100 :         BOOST_CHECK_EQUAL(result12->GetInputSet().size(), 1U); // because in the event of a tie, the biggest coin wins
                   +  - ]
     611                 :             : 
     612                 :             :         // now try making 11 cents.  we should get 5+6
     613   [ +  -  +  - ]:         100 :         const auto result13 = KnapsackSolver(KnapsackGroupOutputs(available_coins, *wallet, filter_confirmed), 11 * CENT, CENT);
     614   [ +  -  +  -  :         200 :         BOOST_CHECK(result13);
                   +  - ]
     615   [ +  -  +  -  :         100 :         BOOST_CHECK_EQUAL(result13->GetSelectedValue(), 11 * CENT);
                   +  - ]
     616   [ +  -  +  -  :         100 :         BOOST_CHECK_EQUAL(result13->GetInputSet().size(), 2U);
                   +  - ]
     617                 :             : 
     618                 :             :         // check that the smallest bigger coin is used
     619         [ +  - ]:         100 :         add_coin(available_coins, *wallet,  1*COIN);
     620         [ +  - ]:         100 :         add_coin(available_coins, *wallet,  2*COIN);
     621         [ +  - ]:         100 :         add_coin(available_coins, *wallet,  3*COIN);
     622         [ +  - ]:         100 :         add_coin(available_coins, *wallet,  4*COIN); // now we have 5+6+7+8+18+20+30+100+200+300+400 = 1094 cents
     623   [ +  -  +  - ]:         100 :         const auto result14 = KnapsackSolver(KnapsackGroupOutputs(available_coins, *wallet, filter_confirmed), 95 * CENT, CENT);
     624   [ +  -  +  -  :         200 :         BOOST_CHECK(result14);
                   +  - ]
     625   [ +  -  +  -  :         100 :         BOOST_CHECK_EQUAL(result14->GetSelectedValue(), 1 * COIN);  // we should get 1 BTC in 1 coin
                   +  - ]
     626   [ +  -  +  -  :         100 :         BOOST_CHECK_EQUAL(result14->GetInputSet().size(), 1U);
                   +  - ]
     627                 :             : 
     628   [ +  -  +  - ]:         100 :         const auto result15 = KnapsackSolver(KnapsackGroupOutputs(available_coins, *wallet, filter_confirmed), 195 * CENT, CENT);
     629   [ +  -  +  -  :         200 :         BOOST_CHECK(result15);
                   +  - ]
     630   [ +  -  +  -  :         100 :         BOOST_CHECK_EQUAL(result15->GetSelectedValue(), 2 * COIN);  // we should get 2 BTC in 1 coin
                   +  - ]
     631   [ +  -  +  -  :         100 :         BOOST_CHECK_EQUAL(result15->GetInputSet().size(), 1U);
                   +  - ]
     632                 :             : 
     633                 :             :         // empty the wallet and start again, now with fractions of a cent, to test small change avoidance
     634                 :             : 
     635         [ +  - ]:         100 :         available_coins.Clear();
     636         [ +  - ]:         100 :         add_coin(available_coins, *wallet, CENT * 1 / 10);
     637         [ +  - ]:         100 :         add_coin(available_coins, *wallet, CENT * 2 / 10);
     638         [ +  - ]:         100 :         add_coin(available_coins, *wallet, CENT * 3 / 10);
     639         [ +  - ]:         100 :         add_coin(available_coins, *wallet, CENT * 4 / 10);
     640         [ +  - ]:         100 :         add_coin(available_coins, *wallet, CENT * 5 / 10);
     641                 :             : 
     642                 :             :         // try making 1 * CENT from the 1.5 * CENT
     643                 :             :         // we'll get change smaller than CENT whatever happens, so can expect CENT exactly
     644   [ +  -  +  - ]:         100 :         const auto result16 = KnapsackSolver(KnapsackGroupOutputs(available_coins, *wallet, filter_confirmed), CENT, CENT);
     645   [ +  -  +  -  :         200 :         BOOST_CHECK(result16);
                   +  - ]
     646   [ +  -  +  -  :         100 :         BOOST_CHECK_EQUAL(result16->GetSelectedValue(), CENT);
                   +  - ]
     647                 :             : 
     648                 :             :         // but if we add a bigger coin, small change is avoided
     649         [ +  - ]:         100 :         add_coin(available_coins, *wallet, 1111*CENT);
     650                 :             : 
     651                 :             :         // try making 1 from 0.1 + 0.2 + 0.3 + 0.4 + 0.5 + 1111 = 1112.5
     652   [ +  -  +  - ]:         100 :         const auto result17 = KnapsackSolver(KnapsackGroupOutputs(available_coins, *wallet, filter_confirmed), 1 * CENT, CENT);
     653   [ +  -  +  -  :         200 :         BOOST_CHECK(result17);
                   +  - ]
     654   [ +  -  +  -  :         100 :         BOOST_CHECK_EQUAL(result17->GetSelectedValue(), 1 * CENT); // we should get the exact amount
                   +  - ]
     655                 :             : 
     656                 :             :         // if we add more small coins:
     657         [ +  - ]:         100 :         add_coin(available_coins, *wallet, CENT * 6 / 10);
     658         [ +  - ]:         100 :         add_coin(available_coins, *wallet, CENT * 7 / 10);
     659                 :             : 
     660                 :             :         // and try again to make 1.0 * CENT
     661   [ +  -  +  - ]:         100 :         const auto result18 = KnapsackSolver(KnapsackGroupOutputs(available_coins, *wallet, filter_confirmed), 1 * CENT, CENT);
     662   [ +  -  +  -  :         200 :         BOOST_CHECK(result18);
                   +  - ]
     663   [ +  -  +  -  :         100 :         BOOST_CHECK_EQUAL(result18->GetSelectedValue(), 1 * CENT); // we should get the exact amount
                   +  - ]
     664                 :             : 
     665                 :             :         // run the 'mtgox' test (see https://blockexplorer.com/tx/29a3efd3ef04f9153d47a990bd7b048a4b2d213daaa5fb8ed670fb85f13bdbcf)
     666                 :             :         // they tried to consolidate 10 50k coins into one 500k coin, and ended up with 50k in change
     667         [ +  - ]:         100 :         available_coins.Clear();
     668         [ +  + ]:        2100 :         for (int j = 0; j < 20; j++)
     669         [ +  - ]:        2000 :             add_coin(available_coins, *wallet, 50000 * COIN);
     670                 :             : 
     671   [ +  -  +  - ]:         100 :         const auto result19 = KnapsackSolver(KnapsackGroupOutputs(available_coins, *wallet, filter_confirmed), 500000 * COIN, CENT);
     672   [ +  -  +  -  :         200 :         BOOST_CHECK(result19);
                   +  - ]
     673   [ +  -  +  -  :         100 :         BOOST_CHECK_EQUAL(result19->GetSelectedValue(), 500000 * COIN); // we should get the exact amount
                   +  - ]
     674   [ +  -  +  -  :         100 :         BOOST_CHECK_EQUAL(result19->GetInputSet().size(), 10U); // in ten coins
                   +  - ]
     675                 :             : 
     676                 :             :         // if there's not enough in the smaller coins to make at least 1 * CENT change (0.5+0.6+0.7 < 1.0+1.0),
     677                 :             :         // we need to try finding an exact subset anyway
     678                 :             : 
     679                 :             :         // sometimes it will fail, and so we use the next biggest coin:
     680         [ +  - ]:         100 :         available_coins.Clear();
     681         [ +  - ]:         100 :         add_coin(available_coins, *wallet, CENT * 5 / 10);
     682         [ +  - ]:         100 :         add_coin(available_coins, *wallet, CENT * 6 / 10);
     683         [ +  - ]:         100 :         add_coin(available_coins, *wallet, CENT * 7 / 10);
     684         [ +  - ]:         100 :         add_coin(available_coins, *wallet, 1111 * CENT);
     685   [ +  -  +  - ]:         100 :         const auto result20 = KnapsackSolver(KnapsackGroupOutputs(available_coins, *wallet, filter_confirmed), 1 * CENT, CENT);
     686   [ +  -  +  -  :         200 :         BOOST_CHECK(result20);
                   +  - ]
     687   [ +  -  +  -  :         100 :         BOOST_CHECK_EQUAL(result20->GetSelectedValue(), 1111 * CENT); // we get the bigger coin
                   +  - ]
     688   [ +  -  +  -  :         100 :         BOOST_CHECK_EQUAL(result20->GetInputSet().size(), 1U);
                   +  - ]
     689                 :             : 
     690                 :             :         // but sometimes it's possible, and we use an exact subset (0.4 + 0.6 = 1.0)
     691         [ +  - ]:         100 :         available_coins.Clear();
     692         [ +  - ]:         100 :         add_coin(available_coins, *wallet, CENT * 4 / 10);
     693         [ +  - ]:         100 :         add_coin(available_coins, *wallet, CENT * 6 / 10);
     694         [ +  - ]:         100 :         add_coin(available_coins, *wallet, CENT * 8 / 10);
     695         [ +  - ]:         100 :         add_coin(available_coins, *wallet, 1111 * CENT);
     696   [ +  -  +  - ]:         100 :         const auto result21 = KnapsackSolver(KnapsackGroupOutputs(available_coins, *wallet, filter_confirmed), CENT, CENT);
     697   [ +  -  +  -  :         200 :         BOOST_CHECK(result21);
                   +  - ]
     698   [ +  -  +  -  :         100 :         BOOST_CHECK_EQUAL(result21->GetSelectedValue(), CENT);   // we should get the exact amount
                   +  - ]
     699   [ +  -  +  -  :         100 :         BOOST_CHECK_EQUAL(result21->GetInputSet().size(), 2U); // in two coins 0.4+0.6
                   +  - ]
     700                 :             : 
     701                 :             :         // test avoiding small change
     702         [ +  - ]:         100 :         available_coins.Clear();
     703         [ +  - ]:         100 :         add_coin(available_coins, *wallet, CENT * 5 / 100);
     704         [ +  - ]:         100 :         add_coin(available_coins, *wallet, CENT * 1);
     705         [ +  - ]:         100 :         add_coin(available_coins, *wallet, CENT * 100);
     706                 :             : 
     707                 :             :         // trying to make 100.01 from these three coins
     708   [ +  -  +  - ]:         100 :         const auto result22 = KnapsackSolver(KnapsackGroupOutputs(available_coins, *wallet, filter_confirmed), CENT * 10001 / 100, CENT);
     709   [ +  -  +  -  :         200 :         BOOST_CHECK(result22);
                   +  - ]
     710   [ +  -  +  -  :         100 :         BOOST_CHECK_EQUAL(result22->GetSelectedValue(), CENT * 10105 / 100); // we should get all coins
                   +  - ]
     711   [ +  -  +  -  :         100 :         BOOST_CHECK_EQUAL(result22->GetInputSet().size(), 3U);
                   +  - ]
     712                 :             : 
     713                 :             :         // but if we try to make 99.9, we should take the bigger of the two small coins to avoid small change
     714   [ +  -  +  - ]:         100 :         const auto result23 = KnapsackSolver(KnapsackGroupOutputs(available_coins, *wallet, filter_confirmed), CENT * 9990 / 100, CENT);
     715   [ +  -  +  -  :         200 :         BOOST_CHECK(result23);
                   +  - ]
     716   [ +  -  +  -  :         100 :         BOOST_CHECK_EQUAL(result23->GetSelectedValue(), 101 * CENT);
                   +  - ]
     717   [ +  -  +  -  :         100 :         BOOST_CHECK_EQUAL(result23->GetInputSet().size(), 2U);
                   +  - ]
     718                 :         100 :     }
     719                 :             : 
     720                 :             :     // test with many inputs
     721         [ +  + ]:           6 :     for (CAmount amt=1500; amt < COIN; amt*=10) {
     722         [ +  - ]:           5 :         available_coins.Clear();
     723                 :             :         // Create 676 inputs (=  (old MAX_STANDARD_TX_SIZE == 100000)  / 148 bytes per input)
     724         [ +  + ]:        3385 :         for (uint16_t j = 0; j < 676; j++)
     725         [ +  - ]:        3380 :             add_coin(available_coins, *wallet, amt);
     726                 :             : 
     727                 :             :         // We only create the wallet once to save time, but we still run the coin selection RUN_TESTS times.
     728         [ +  + ]:         505 :         for (int i = 0; i < RUN_TESTS; i++) {
     729   [ +  -  +  - ]:         500 :             const auto result24 = KnapsackSolver(KnapsackGroupOutputs(available_coins, *wallet, filter_confirmed), 2000, CENT);
     730   [ +  -  +  -  :        1000 :             BOOST_CHECK(result24);
                   +  + ]
     731                 :             : 
     732         [ +  + ]:         500 :             if (amt - 2000 < CENT) {
     733                 :             :                 // needs more than one input:
     734                 :         300 :                 uint16_t returnSize = std::ceil((2000.0 + CENT)/amt);
     735                 :         300 :                 CAmount returnValue = amt * returnSize;
     736   [ +  -  +  -  :         300 :                 BOOST_CHECK_EQUAL(result24->GetSelectedValue(), returnValue);
                   +  - ]
     737   [ +  -  +  -  :         300 :                 BOOST_CHECK_EQUAL(result24->GetInputSet().size(), returnSize);
                   +  - ]
     738                 :             :             } else {
     739                 :             :                 // one input is sufficient:
     740   [ +  -  +  -  :         200 :                 BOOST_CHECK_EQUAL(result24->GetSelectedValue(), amt);
                   +  - ]
     741   [ +  -  +  -  :         200 :                 BOOST_CHECK_EQUAL(result24->GetInputSet().size(), 1U);
                   +  - ]
     742                 :             :             }
     743                 :         500 :         }
     744                 :             :     }
     745                 :             : 
     746                 :             :     // test randomness
     747                 :           1 :     {
     748         [ +  - ]:           1 :         available_coins.Clear();
     749         [ +  + ]:         101 :         for (int i2 = 0; i2 < 100; i2++)
     750         [ +  - ]:         100 :             add_coin(available_coins, *wallet, COIN);
     751                 :             : 
     752                 :             :         // Again, we only create the wallet once to save time, but we still run the coin selection RUN_TESTS times.
     753         [ +  + ]:         101 :         for (int i = 0; i < RUN_TESTS; i++) {
     754                 :             :             // picking 50 from 100 coins doesn't depend on the shuffle,
     755                 :             :             // but does depend on randomness in the stochastic approximation code
     756   [ +  -  +  -  :         100 :             const auto result25 = KnapsackSolver(GroupCoins(available_coins.All()), 50 * COIN, CENT);
                   +  - ]
     757   [ +  -  +  -  :         200 :             BOOST_CHECK(result25);
                   +  - ]
     758   [ +  -  +  -  :         100 :             const auto result26 = KnapsackSolver(GroupCoins(available_coins.All()), 50 * COIN, CENT);
                   +  - ]
     759   [ +  -  +  -  :         200 :             BOOST_CHECK(result26);
                   +  - ]
     760   [ +  -  +  -  :         200 :             BOOST_CHECK(!EqualResult(*result25, *result26));
                   +  - ]
     761                 :             : 
     762                 :         100 :             int fails = 0;
     763         [ +  + ]:         600 :             for (int j = 0; j < RANDOM_REPEATS; j++)
     764                 :             :             {
     765                 :             :                 // Test that the KnapsackSolver selects randomly from equivalent coins (same value and same input size).
     766                 :             :                 // When choosing 1 from 100 identical coins, 1% of the time, this test will choose the same coin twice
     767                 :             :                 // which will cause it to fail.
     768                 :             :                 // To avoid that issue, run the test RANDOM_REPEATS times and only complain if all of them fail
     769   [ +  -  +  -  :         500 :                 const auto result27 = KnapsackSolver(GroupCoins(available_coins.All()), COIN, CENT);
                   +  - ]
     770   [ +  -  +  -  :        1000 :                 BOOST_CHECK(result27);
                   +  - ]
     771   [ +  -  +  -  :         500 :                 const auto result28 = KnapsackSolver(GroupCoins(available_coins.All()), COIN, CENT);
                   +  - ]
     772   [ +  -  +  -  :        1000 :                 BOOST_CHECK(result28);
                   +  - ]
     773   [ +  -  +  + ]:         500 :                 if (EqualResult(*result27, *result28))
     774                 :           4 :                     fails++;
     775                 :         500 :             }
     776   [ +  -  +  - ]:         100 :             BOOST_CHECK_NE(fails, RANDOM_REPEATS);
     777                 :         100 :         }
     778                 :             : 
     779                 :             :         // add 75 cents in small change.  not enough to make 90 cents,
     780                 :             :         // then try making 90 cents.  there are multiple competing "smallest bigger" coins,
     781                 :             :         // one of which should be picked at random
     782         [ +  - ]:           1 :         add_coin(available_coins, *wallet, 5 * CENT);
     783         [ +  - ]:           1 :         add_coin(available_coins, *wallet, 10 * CENT);
     784         [ +  - ]:           1 :         add_coin(available_coins, *wallet, 15 * CENT);
     785         [ +  - ]:           1 :         add_coin(available_coins, *wallet, 20 * CENT);
     786         [ +  - ]:           1 :         add_coin(available_coins, *wallet, 25 * CENT);
     787                 :             : 
     788         [ +  + ]:         101 :         for (int i = 0; i < RUN_TESTS; i++) {
     789                 :         100 :             int fails = 0;
     790         [ +  + ]:         600 :             for (int j = 0; j < RANDOM_REPEATS; j++)
     791                 :             :             {
     792   [ +  -  +  -  :         500 :                 const auto result29 = KnapsackSolver(GroupCoins(available_coins.All()), 90 * CENT, CENT);
                   +  - ]
     793   [ +  -  +  -  :        1000 :                 BOOST_CHECK(result29);
                   +  - ]
     794   [ +  -  +  -  :         500 :                 const auto result30 = KnapsackSolver(GroupCoins(available_coins.All()), 90 * CENT, CENT);
                   +  - ]
     795   [ +  -  +  -  :        1000 :                 BOOST_CHECK(result30);
                   +  - ]
     796   [ +  -  +  + ]:         500 :                 if (EqualResult(*result29, *result30))
     797                 :           4 :                     fails++;
     798                 :         500 :             }
     799   [ +  -  +  - ]:         100 :             BOOST_CHECK_NE(fails, RANDOM_REPEATS);
     800                 :             :         }
     801                 :             :     }
     802         [ +  - ]:           2 : }
     803                 :             : 
     804   [ +  -  +  -  :           7 : BOOST_AUTO_TEST_CASE(ApproximateBestSubset)
          +  -  +  -  +  
          -  +  -  +  -  
          +  -  +  -  +  
          -  +  -  +  -  
          +  -  +  -  +  
          -  +  -  +  -  
          +  -  +  -  +  
          -  +  -  +  -  
          +  -  +  -  +  
          -  +  -  +  -  
          +  -  +  -  +  
                      - ]
     805                 :             : {
     806                 :           1 :     FastRandomContext rand{};
     807   [ +  -  +  - ]:           1 :     std::unique_ptr<CWallet> wallet = NewWallet(m_node);
     808                 :             : 
     809                 :           1 :     CoinsResult available_coins;
     810                 :             : 
     811                 :             :     // Test vValue sort order
     812         [ +  + ]:        1001 :     for (int i = 0; i < 1000; i++)
     813         [ +  - ]:        1000 :         add_coin(available_coins, *wallet, 1000 * COIN);
     814         [ +  - ]:           1 :     add_coin(available_coins, *wallet, 3 * COIN);
     815                 :             : 
     816   [ +  -  +  - ]:           1 :     const auto result = KnapsackSolver(KnapsackGroupOutputs(available_coins, *wallet, filter_standard), 1003 * COIN, CENT, rand);
     817   [ +  -  +  -  :           2 :     BOOST_CHECK(result);
                   +  - ]
     818   [ +  -  +  -  :           1 :     BOOST_CHECK_EQUAL(result->GetSelectedValue(), 1003 * COIN);
                   +  - ]
     819   [ +  -  +  -  :           1 :     BOOST_CHECK_EQUAL(result->GetInputSet().size(), 2U);
                   +  - ]
     820         [ +  - ]:           2 : }
     821                 :             : 
     822                 :             : // Tests that with the ideal conditions, the coin selector will always be able to find a solution that can pay the target value
     823   [ +  -  +  -  :           7 : BOOST_AUTO_TEST_CASE(SelectCoins_test)
          +  -  +  -  +  
          -  +  -  +  -  
          +  -  +  -  +  
          -  +  -  +  -  
          +  -  +  -  +  
          -  +  -  +  -  
          +  -  +  -  +  
          -  +  -  +  -  
          +  -  +  -  +  
          -  +  -  +  -  
          +  -  +  -  +  
                      - ]
     824                 :             : {
     825         [ +  - ]:           1 :     std::unique_ptr<CWallet> wallet = NewWallet(m_node);
     826         [ +  - ]:           1 :     LOCK(wallet->cs_wallet); // Every 'SelectCoins' call requires it
     827                 :             : 
     828                 :             :     // Random generator stuff
     829                 :           1 :     std::default_random_engine generator;
     830                 :           1 :     std::exponential_distribution<double> distribution (100);
     831                 :           1 :     FastRandomContext rand;
     832                 :             : 
     833                 :             :     // Run this test 100 times
     834         [ +  + ]:         101 :     for (int i = 0; i < 100; ++i)
     835                 :             :     {
     836                 :         100 :         CoinsResult available_coins;
     837                 :         100 :         CAmount balance{0};
     838                 :             : 
     839                 :             :         // Make a wallet with 1000 exponentially distributed random inputs
     840         [ +  + ]:      100100 :         for (int j = 0; j < 1000; ++j)
     841                 :             :         {
     842                 :      100000 :             CAmount val = distribution(generator)*10000000;
     843         [ +  - ]:      100000 :             add_coin(available_coins, *wallet, val);
     844                 :      100000 :             balance += val;
     845                 :             :         }
     846                 :             : 
     847                 :             :         // Generate a random fee rate in the range of 100 - 400
     848                 :         100 :         CFeeRate rate(rand.randrange(300) + 100);
     849                 :             : 
     850                 :             :         // Generate a random target value between 1000 and wallet balance
     851                 :         100 :         CAmount target = rand.randrange(balance - 1000) + 1000;
     852                 :             : 
     853                 :             :         // Perform selection
     854         [ +  - ]:         100 :         CoinSelectionParams cs_params{
     855                 :             :             rand,
     856                 :             :             /*change_output_size=*/ 34,
     857                 :             :             /*change_spend_size=*/ 148,
     858                 :             :             /*min_change_target=*/ CENT,
     859                 :         100 :             /*effective_feerate=*/ CFeeRate(0),
     860                 :         100 :             /*long_term_feerate=*/ CFeeRate(0),
     861         [ +  - ]:         100 :             /*discard_feerate=*/ CFeeRate(0),
     862                 :             :             /*tx_noinputs_size=*/ 0,
     863                 :             :             /*avoid_partial=*/ false,
     864                 :         100 :         };
     865                 :         100 :         cs_params.m_cost_of_change = 1;
     866                 :         100 :         cs_params.min_viable_change = 1;
     867         [ +  - ]:         100 :         CCoinControl cc;
     868                 :           0 :         const auto result = SelectCoins(*wallet, available_coins, /*pre_set_inputs=*/{}, target, cc, cs_params);
     869   [ +  -  +  -  :         200 :         BOOST_CHECK(result);
                   +  - ]
     870   [ +  -  +  -  :         100 :         BOOST_CHECK_GE(result->GetSelectedValue(), target);
                   +  - ]
     871                 :         100 :     }
     872   [ +  -  +  -  :         103 : }
                   +  - ]
     873                 :             : 
     874   [ +  -  +  -  :           7 : BOOST_AUTO_TEST_CASE(waste_test)
          +  -  +  -  +  
          -  +  -  +  -  
          +  -  +  -  +  
          -  +  -  +  -  
          +  -  +  -  +  
          -  +  -  +  -  
          +  -  +  -  +  
          -  +  -  +  -  
          +  -  +  -  +  
          -  +  -  +  -  
          +  -  +  -  +  
                      - ]
     875                 :             : {
     876                 :           1 :     const CAmount fee{100};
     877                 :           1 :     const CAmount min_viable_change{300};
     878                 :           1 :     const CAmount change_cost{125};
     879                 :           1 :     const CAmount change_fee{30};
     880                 :           1 :     const CAmount fee_diff{40};
     881                 :           1 :     const CAmount in_amt{3 * COIN};
     882                 :           1 :     const CAmount target{2 * COIN};
     883                 :           1 :     const CAmount excess{80};
     884                 :           1 :     const CAmount exact_target{in_amt - fee * 2}; // Maximum spendable amount after fees: no change, no excess
     885                 :             : 
     886                 :             :     // In the following, we test that the waste is calculated correctly in various scenarios.
     887                 :             :     // Usually, RecalculateWaste would compute change_fee and change_cost on basis of the
     888                 :             :     // change output type, current feerate, and discard_feerate, but we use fixed values
     889                 :             :     // across this test to make the test easier to understand.
     890                 :           1 :     {
     891                 :             :         // Waste with change is the change cost and difference between fee and long term fee
     892         [ +  - ]:           1 :         SelectionResult selection1{target, SelectionAlgorithm::MANUAL};
     893         [ +  - ]:           1 :         add_coin(1 * COIN, 1, selection1, /*fee=*/fee, /*long_term_fee=*/fee - fee_diff);
     894         [ +  - ]:           1 :         add_coin(2 * COIN, 2, selection1, fee, fee - fee_diff);
     895         [ +  - ]:           1 :         selection1.RecalculateWaste(min_viable_change, change_cost, change_fee);
     896   [ +  -  +  -  :           1 :         BOOST_CHECK_EQUAL(fee_diff * 2 + change_cost, selection1.GetWaste());
                   +  - ]
     897                 :             : 
     898                 :             :         // Waste will be greater when fee is greater, but long term fee is the same
     899         [ +  - ]:           1 :         SelectionResult selection2{target, SelectionAlgorithm::MANUAL};
     900         [ +  - ]:           1 :         add_coin(1 * COIN, 1, selection2, fee * 2, fee - fee_diff);
     901         [ +  - ]:           1 :         add_coin(2 * COIN, 2, selection2, fee * 2, fee - fee_diff);
     902         [ +  - ]:           1 :         selection2.RecalculateWaste(min_viable_change, change_cost, change_fee);
     903   [ +  -  +  -  :           1 :         BOOST_CHECK_GT(selection2.GetWaste(), selection1.GetWaste());
             +  -  +  - ]
     904                 :             : 
     905                 :             :         // Waste with change is the change cost and difference between fee and long term fee
     906                 :             :         // With long term fee greater than fee, waste should be less than when long term fee is less than fee
     907         [ +  - ]:           1 :         SelectionResult selection3{target, SelectionAlgorithm::MANUAL};
     908         [ +  - ]:           1 :         add_coin(1 * COIN, 1, selection3, fee, fee + fee_diff);
     909         [ +  - ]:           1 :         add_coin(2 * COIN, 2, selection3, fee, fee + fee_diff);
     910         [ +  - ]:           1 :         selection3.RecalculateWaste(min_viable_change, change_cost, change_fee);
     911   [ +  -  +  -  :           1 :         BOOST_CHECK_EQUAL(fee_diff * -2 + change_cost, selection3.GetWaste());
                   +  - ]
     912   [ +  -  +  -  :           1 :         BOOST_CHECK_LT(selection3.GetWaste(), selection1.GetWaste());
             +  -  +  - ]
     913                 :           1 :     }
     914                 :             : 
     915                 :           1 :     {
     916                 :             :         // Waste without change is the excess and difference between fee and long term fee
     917         [ +  - ]:           1 :         SelectionResult selection_nochange1{exact_target - excess, SelectionAlgorithm::MANUAL};
     918         [ +  - ]:           1 :         add_coin(1 * COIN, 1, selection_nochange1, fee, fee - fee_diff);
     919         [ +  - ]:           1 :         add_coin(2 * COIN, 2, selection_nochange1, fee, fee - fee_diff);
     920         [ +  - ]:           1 :         selection_nochange1.RecalculateWaste(min_viable_change, change_cost, change_fee);
     921   [ +  -  +  -  :           1 :         BOOST_CHECK_EQUAL(fee_diff * 2 + excess, selection_nochange1.GetWaste());
                   +  - ]
     922                 :             : 
     923                 :             :         // Waste without change is the excess and difference between fee and long term fee
     924                 :             :         // With long term fee greater than fee, waste should be less than when long term fee is less than fee
     925         [ +  - ]:           1 :         SelectionResult selection_nochange2{exact_target - excess, SelectionAlgorithm::MANUAL};
     926         [ +  - ]:           1 :         add_coin(1 * COIN, 1, selection_nochange2, fee, fee + fee_diff);
     927         [ +  - ]:           1 :         add_coin(2 * COIN, 2, selection_nochange2, fee, fee + fee_diff);
     928         [ +  - ]:           1 :         selection_nochange2.RecalculateWaste(min_viable_change, change_cost, change_fee);
     929   [ +  -  +  -  :           1 :         BOOST_CHECK_EQUAL(fee_diff * -2 + excess, selection_nochange2.GetWaste());
                   +  - ]
     930   [ +  -  +  -  :           1 :         BOOST_CHECK_LT(selection_nochange2.GetWaste(), selection_nochange1.GetWaste());
             +  -  +  - ]
     931                 :           1 :     }
     932                 :             : 
     933                 :           1 :     {
     934                 :             :         // Waste with change and fee == long term fee is just cost of change
     935         [ +  - ]:           1 :         SelectionResult selection{target, SelectionAlgorithm::MANUAL};
     936         [ +  - ]:           1 :         add_coin(1 * COIN, 1, selection, fee, fee);
     937         [ +  - ]:           1 :         add_coin(2 * COIN, 2, selection, fee, fee);
     938         [ +  - ]:           1 :         selection.RecalculateWaste(min_viable_change, change_cost, change_fee);
     939   [ +  -  +  -  :           1 :         BOOST_CHECK_EQUAL(change_cost, selection.GetWaste());
                   +  - ]
     940                 :           0 :     }
     941                 :             : 
     942                 :           1 :     {
     943                 :             :         // Waste without change and fee == long term fee is just the excess
     944         [ +  - ]:           1 :         SelectionResult selection{exact_target - excess, SelectionAlgorithm::MANUAL};
     945         [ +  - ]:           1 :         add_coin(1 * COIN, 1, selection, fee, fee);
     946         [ +  - ]:           1 :         add_coin(2 * COIN, 2, selection, fee, fee);
     947         [ +  - ]:           1 :         selection.RecalculateWaste(min_viable_change, change_cost, change_fee);
     948   [ +  -  +  -  :           1 :         BOOST_CHECK_EQUAL(excess, selection.GetWaste());
                   +  - ]
     949                 :           0 :     }
     950                 :             : 
     951                 :           1 :     {
     952                 :             :         // Waste is 0 when fee == long_term_fee, no change, and no excess
     953         [ +  - ]:           1 :         SelectionResult selection{exact_target, SelectionAlgorithm::MANUAL};
     954         [ +  - ]:           1 :         add_coin(1 * COIN, 1, selection, fee, fee);
     955         [ +  - ]:           1 :         add_coin(2 * COIN, 2, selection, fee, fee);
     956         [ +  - ]:           1 :         selection.RecalculateWaste(min_viable_change, change_cost , change_fee);
     957   [ +  -  +  -  :           1 :         BOOST_CHECK_EQUAL(0, selection.GetWaste());
                   +  - ]
     958                 :           0 :     }
     959                 :             : 
     960                 :           1 :     {
     961                 :             :         // Waste is 0 when (fee - long_term_fee) == (-cost_of_change), and no excess
     962         [ +  - ]:           1 :         SelectionResult selection{target, SelectionAlgorithm::MANUAL};
     963         [ +  - ]:           1 :         add_coin(1 * COIN, 1, selection, fee, fee + fee_diff);
     964         [ +  - ]:           1 :         add_coin(2 * COIN, 2, selection, fee, fee + fee_diff);
     965         [ +  - ]:           1 :         selection.RecalculateWaste(min_viable_change, /*change_cost=*/fee_diff * 2, change_fee);
     966   [ +  -  +  -  :           1 :         BOOST_CHECK_EQUAL(0, selection.GetWaste());
                   +  - ]
     967                 :           0 :     }
     968                 :             : 
     969                 :           1 :     {
     970                 :             :         // Waste is 0 when (fee - long_term_fee) == (-excess), no change cost
     971                 :           1 :         const CAmount new_target{exact_target - /*excess=*/fee_diff * 2};
     972         [ +  - ]:           1 :         SelectionResult selection{new_target, SelectionAlgorithm::MANUAL};
     973         [ +  - ]:           1 :         add_coin(1 * COIN, 1, selection, fee, fee + fee_diff);
     974         [ +  - ]:           1 :         add_coin(2 * COIN, 2, selection, fee, fee + fee_diff);
     975         [ +  - ]:           1 :         selection.RecalculateWaste(min_viable_change, change_cost, change_fee);
     976   [ +  -  +  -  :           1 :         BOOST_CHECK_EQUAL(0, selection.GetWaste());
                   +  - ]
     977                 :           0 :     }
     978                 :             : 
     979                 :           1 :     {
     980                 :             :         // Negative waste when the long term fee is greater than the current fee and the selected value == target
     981         [ +  - ]:           1 :         SelectionResult selection{exact_target, SelectionAlgorithm::MANUAL};
     982                 :           1 :         const CAmount target_waste1{-2 * fee_diff}; // = (2 * fee) - (2 * (fee + fee_diff))
     983         [ +  - ]:           1 :         add_coin(1 * COIN, 1, selection, fee, fee + fee_diff);
     984         [ +  - ]:           1 :         add_coin(2 * COIN, 2, selection, fee, fee + fee_diff);
     985         [ +  - ]:           1 :         selection.RecalculateWaste(min_viable_change, change_cost, change_fee);
     986   [ +  -  +  -  :           1 :         BOOST_CHECK_EQUAL(target_waste1, selection.GetWaste());
                   +  - ]
     987                 :           0 :     }
     988                 :             : 
     989                 :           1 :     {
     990                 :             :         // Negative waste when the long term fee is greater than the current fee and change_cost < - (inputs * (fee - long_term_fee))
     991         [ +  - ]:           1 :         SelectionResult selection{target, SelectionAlgorithm::MANUAL};
     992                 :           1 :         const CAmount large_fee_diff{90};
     993                 :           1 :         const CAmount target_waste2{-2 * large_fee_diff + change_cost};
     994                 :             :         // = (2 * fee) - (2 * (fee + large_fee_diff)) + change_cost
     995                 :             :         // = (2 * 100) - (2 * (100 + 90)) + 125
     996                 :             :         // = 200 - 380 + 125 = -55
     997                 :           1 :         assert(target_waste2 == -55);
     998         [ +  - ]:           1 :         add_coin(1 * COIN, 1, selection, fee, fee + large_fee_diff);
     999         [ +  - ]:           1 :         add_coin(2 * COIN, 2, selection, fee, fee + large_fee_diff);
    1000         [ +  - ]:           1 :         selection.RecalculateWaste(min_viable_change, change_cost, change_fee);
    1001   [ +  -  +  -  :           1 :         BOOST_CHECK_EQUAL(target_waste2, selection.GetWaste());
                   +  - ]
    1002                 :           1 :     }
    1003                 :           1 : }
    1004                 :             : 
    1005                 :             : 
    1006   [ +  -  +  -  :           7 : BOOST_AUTO_TEST_CASE(bump_fee_test)
          +  -  +  -  +  
          -  +  -  +  -  
          +  -  +  -  +  
          -  +  -  +  -  
          +  -  +  -  +  
          -  +  -  +  -  
          +  -  +  -  +  
          -  +  -  +  -  
          +  -  +  -  +  
          -  +  -  +  -  
          +  -  +  -  +  
                      - ]
    1007                 :             : {
    1008                 :           1 :     const CAmount fee{100};
    1009                 :           1 :     const CAmount min_viable_change{200};
    1010                 :           1 :     const CAmount change_cost{125};
    1011                 :           1 :     const CAmount change_fee{35};
    1012                 :           1 :     const CAmount fee_diff{40};
    1013                 :           1 :     const CAmount target{2 * COIN};
    1014                 :             : 
    1015                 :           1 :     {
    1016         [ +  - ]:           1 :         SelectionResult selection{target, SelectionAlgorithm::MANUAL};
    1017         [ +  - ]:           1 :         add_coin(1 * COIN, 1, selection, /*fee=*/fee, /*long_term_fee=*/fee + fee_diff);
    1018         [ +  - ]:           1 :         add_coin(2 * COIN, 2, selection, fee, fee + fee_diff);
    1019         [ +  - ]:           1 :         const std::vector<std::shared_ptr<COutput>> inputs = selection.GetShuffledInputVector();
    1020                 :             : 
    1021         [ +  + ]:           3 :         for (size_t i = 0; i < inputs.size(); ++i) {
    1022                 :           2 :             inputs[i]->ApplyBumpFee(20*(i+1));
    1023                 :             :         }
    1024                 :             : 
    1025         [ +  - ]:           1 :         selection.RecalculateWaste(min_viable_change, change_cost, change_fee);
    1026                 :           1 :         CAmount expected_waste = fee_diff * -2 + change_cost + /*bump_fees=*/60;
    1027   [ +  -  +  -  :           1 :         BOOST_CHECK_EQUAL(expected_waste, selection.GetWaste());
                   +  - ]
    1028                 :             : 
    1029         [ +  - ]:           1 :         selection.SetBumpFeeDiscount(30);
    1030         [ +  - ]:           1 :         selection.RecalculateWaste(min_viable_change, change_cost, change_fee);
    1031                 :           1 :         expected_waste = fee_diff * -2 + change_cost + /*bump_fees=*/60 - /*group_discount=*/30;
    1032   [ +  -  +  -  :           1 :         BOOST_CHECK_EQUAL(expected_waste, selection.GetWaste());
                   +  - ]
    1033                 :           1 :     }
    1034                 :             : 
    1035                 :           1 :     {
    1036                 :             :         // Test with changeless transaction
    1037                 :             :         //
    1038                 :             :         // Bump fees and excess both contribute fully to the waste score,
    1039                 :             :         // therefore, a bump fee group discount will not change the waste
    1040                 :             :         // score as long as we do not create change in both instances.
    1041                 :           1 :         CAmount changeless_target = 3 * COIN - 2 * fee - 100;
    1042         [ +  - ]:           1 :         SelectionResult selection{changeless_target, SelectionAlgorithm::MANUAL};
    1043         [ +  - ]:           1 :         add_coin(1 * COIN, 1, selection, /*fee=*/fee, /*long_term_fee=*/fee + fee_diff);
    1044         [ +  - ]:           1 :         add_coin(2 * COIN, 2, selection, fee, fee + fee_diff);
    1045         [ +  - ]:           1 :         const std::vector<std::shared_ptr<COutput>> inputs = selection.GetShuffledInputVector();
    1046                 :             : 
    1047         [ +  + ]:           3 :         for (size_t i = 0; i < inputs.size(); ++i) {
    1048                 :           2 :             inputs[i]->ApplyBumpFee(20*(i+1));
    1049                 :             :         }
    1050                 :             : 
    1051         [ +  - ]:           1 :         selection.RecalculateWaste(min_viable_change, change_cost, change_fee);
    1052                 :           1 :         CAmount expected_waste = fee_diff * -2 + /*bump_fees=*/60 + /*excess = 100 - bump_fees*/40;
    1053   [ +  -  +  -  :           1 :         BOOST_CHECK_EQUAL(expected_waste, selection.GetWaste());
                   +  - ]
    1054                 :             : 
    1055         [ +  - ]:           1 :         selection.SetBumpFeeDiscount(30);
    1056         [ +  - ]:           1 :         selection.RecalculateWaste(min_viable_change, change_cost, change_fee);
    1057                 :           1 :         expected_waste = fee_diff * -2 + /*bump_fees=*/60 - /*group_discount=*/30 + /*excess = 100 - bump_fees + group_discount*/70;
    1058   [ +  -  +  -  :           1 :         BOOST_CHECK_EQUAL(expected_waste, selection.GetWaste());
                   +  - ]
    1059                 :           1 :     }
    1060                 :           1 : }
    1061                 :             : 
    1062   [ +  -  +  -  :           7 : BOOST_AUTO_TEST_CASE(effective_value_test)
          +  -  +  -  +  
          -  +  -  +  -  
          +  -  +  -  +  
          -  +  -  +  -  
          +  -  +  -  +  
          -  +  -  +  -  
          +  -  +  -  +  
          -  +  -  +  -  
          +  -  +  -  +  
          -  +  -  +  -  
          +  -  +  -  +  
                      - ]
    1063                 :             : {
    1064                 :           1 :     const int input_bytes = 148;
    1065                 :           1 :     const CFeeRate feerate(1000);
    1066                 :           1 :     const CAmount nValue = 10000;
    1067                 :           1 :     const int nInput = 0;
    1068                 :             : 
    1069                 :           1 :     CMutableTransaction tx;
    1070         [ +  - ]:           1 :     tx.vout.resize(1);
    1071         [ +  - ]:           1 :     tx.vout[nInput].nValue = nValue;
    1072                 :             : 
    1073                 :             :     // standard case, pass feerate in constructor
    1074   [ +  -  +  -  :           1 :     COutput output1(COutPoint(tx.GetHash(), nInput), tx.vout.at(nInput), /*depth=*/ 1, input_bytes, /*spendable=*/ true, /*solvable=*/ true, /*safe=*/ true, /*time=*/ 0, /*from_me=*/ false, feerate);
                   +  - ]
    1075                 :           1 :     const CAmount expected_ev1 = 9852; // 10000 - 148
    1076   [ +  -  +  - ]:           1 :     BOOST_CHECK_EQUAL(output1.GetEffectiveValue(), expected_ev1);
    1077                 :             : 
    1078                 :             :     // input bytes unknown (input_bytes = -1), pass feerate in constructor
    1079   [ +  -  +  -  :           1 :     COutput output2(COutPoint(tx.GetHash(), nInput), tx.vout.at(nInput), /*depth=*/ 1, /*input_bytes=*/ -1, /*spendable=*/ true, /*solvable=*/ true, /*safe=*/ true, /*time=*/ 0, /*from_me=*/ false, feerate);
                   +  - ]
    1080   [ +  -  +  - ]:           1 :     BOOST_CHECK_EQUAL(output2.GetEffectiveValue(), nValue); // The effective value should be equal to the absolute value if input_bytes is -1
    1081                 :             : 
    1082                 :             :     // negative effective value, pass feerate in constructor
    1083   [ +  -  +  -  :           1 :     COutput output3(COutPoint(tx.GetHash(), nInput), tx.vout.at(nInput), /*depth=*/ 1, input_bytes, /*spendable=*/ true, /*solvable=*/ true, /*safe=*/ true, /*time=*/ 0, /*from_me=*/ false, CFeeRate(100000));
                   +  - ]
    1084                 :           1 :     const CAmount expected_ev3 = -4800; // 10000 - 14800
    1085   [ +  -  +  - ]:           1 :     BOOST_CHECK_EQUAL(output3.GetEffectiveValue(), expected_ev3);
    1086                 :             : 
    1087                 :             :     // standard case, pass fees in constructor
    1088                 :           1 :     const CAmount fees = 148;
    1089   [ +  -  +  -  :           1 :     COutput output4(COutPoint(tx.GetHash(), nInput), tx.vout.at(nInput), /*depth=*/ 1, input_bytes, /*spendable=*/ true, /*solvable=*/ true, /*safe=*/ true, /*time=*/ 0, /*from_me=*/ false, fees);
                   +  - ]
    1090   [ +  -  +  - ]:           1 :     BOOST_CHECK_EQUAL(output4.GetEffectiveValue(), expected_ev1);
    1091                 :             : 
    1092                 :             :     // input bytes unknown (input_bytes = -1), pass fees in constructor
    1093   [ +  -  +  -  :           1 :     COutput output5(COutPoint(tx.GetHash(), nInput), tx.vout.at(nInput), /*depth=*/ 1, /*input_bytes=*/ -1, /*spendable=*/ true, /*solvable=*/ true, /*safe=*/ true, /*time=*/ 0, /*from_me=*/ false, /*fees=*/ 0);
                   +  - ]
    1094   [ +  -  +  - ]:           1 :     BOOST_CHECK_EQUAL(output5.GetEffectiveValue(), nValue); // The effective value should be equal to the absolute value if input_bytes is -1
    1095                 :           2 : }
    1096                 :             : 
    1097                 :           7 : static util::Result<SelectionResult> CoinGrinder(const CAmount& target,
    1098                 :             :                                                     const CoinSelectionParams& cs_params,
    1099                 :             :                                                     const node::NodeContext& m_node,
    1100                 :             :                                                     int max_selection_weight,
    1101                 :             :                                                     std::function<CoinsResult(CWallet&)> coin_setup)
    1102                 :             : {
    1103         [ +  - ]:           7 :     std::unique_ptr<CWallet> wallet = NewWallet(m_node);
    1104         [ +  - ]:           7 :     CoinEligibilityFilter filter(0, 0, 0); // accept all coins without ancestors
    1105   [ +  -  +  -  :          14 :     Groups group = GroupOutputs(*wallet, coin_setup(*wallet), cs_params, {{filter}})[filter].all_groups;
          +  -  +  -  +  
                -  +  - ]
    1106         [ +  - ]:           7 :     return CoinGrinder(group.positive_group, target, cs_params.m_min_change_target, max_selection_weight);
    1107         [ +  - ]:          14 : }
    1108                 :             : 
    1109   [ +  -  +  -  :           7 : BOOST_AUTO_TEST_CASE(coin_grinder_tests)
          +  -  +  -  +  
          -  +  -  +  -  
          +  -  +  -  +  
          -  +  -  +  -  
          +  -  +  -  +  
          -  +  -  +  -  
          +  -  +  -  +  
          -  +  -  +  -  
          +  -  +  -  +  
          -  +  -  +  -  
          +  -  +  -  +  
                      - ]
    1110                 :             : {
    1111                 :             :     // Test Coin Grinder:
    1112                 :             :     // 1) Insufficient funds, select all provided coins and fail.
    1113                 :             :     // 2) Exceeded max weight, coin selection always surpasses the max allowed weight.
    1114                 :             :     // 3) Select coins without surpassing the max weight (some coins surpasses the max allowed weight, some others not)
    1115                 :             :     // 4) Test that two less valuable UTXOs with a combined lower weight are preferred over a more valuable heavier UTXO
    1116                 :             :     // 5) Test finding a solution in a UTXO pool with mixed weights
    1117                 :             :     // 6) Test that the lightest solution among many clones is found
    1118                 :             :     // 7) Test that lots of tiny UTXOs can be skipped if they are too heavy while there are enough funds in lookahead
    1119                 :             : 
    1120                 :           1 :     FastRandomContext rand;
    1121         [ +  - ]:           1 :     CoinSelectionParams dummy_params{ // Only used to provide the 'avoid_partial' flag.
    1122                 :             :             rand,
    1123                 :             :             /*change_output_size=*/34,
    1124                 :             :             /*change_spend_size=*/68,
    1125                 :             :             /*min_change_target=*/CENT,
    1126                 :           1 :             /*effective_feerate=*/CFeeRate(5000),
    1127                 :           1 :             /*long_term_feerate=*/CFeeRate(2000),
    1128         [ +  - ]:           1 :             /*discard_feerate=*/CFeeRate(1000),
    1129                 :             :             /*tx_noinputs_size=*/10 + 34, // static header size + output size
    1130                 :             :             /*avoid_partial=*/false,
    1131                 :           1 :     };
    1132                 :             : 
    1133                 :           1 :     {
    1134                 :             :         // #########################################################
    1135                 :             :         // 1) Insufficient funds, select all provided coins and fail
    1136                 :             :         // #########################################################
    1137                 :           1 :         CAmount target = 49.5L * COIN;
    1138                 :           1 :         int max_selection_weight = 10'000; // high enough to not fail for this reason.
    1139         [ +  - ]:           2 :         const auto& res = CoinGrinder(target, dummy_params, m_node, max_selection_weight, [&](CWallet& wallet) {
    1140                 :           1 :             CoinsResult available_coins;
    1141         [ +  + ]:          11 :             for (int j = 0; j < 10; ++j) {
    1142         [ +  - ]:          10 :                 add_coin(available_coins, wallet, CAmount(1 * COIN));
    1143         [ +  - ]:          10 :                 add_coin(available_coins, wallet, CAmount(2 * COIN));
    1144                 :             :             }
    1145                 :           1 :             return available_coins;
    1146         [ +  - ]:           1 :         });
    1147   [ +  -  +  -  :           2 :         BOOST_CHECK(!res);
                   +  - ]
    1148   [ +  -  +  -  :           3 :         BOOST_CHECK(util::ErrorString(res).empty()); // empty means "insufficient funds"
                   +  - ]
    1149                 :           0 :     }
    1150                 :             : 
    1151                 :           1 :     {
    1152                 :             :         // ###########################
    1153                 :             :         // 2) Test max weight exceeded
    1154                 :             :         // ###########################
    1155                 :           1 :         CAmount target = 29.5L * COIN;
    1156                 :           1 :         int max_selection_weight = 3000;
    1157         [ +  - ]:           2 :         const auto& res = CoinGrinder(target, dummy_params, m_node, max_selection_weight, [&](CWallet& wallet) {
    1158                 :           1 :             CoinsResult available_coins;
    1159         [ +  + ]:          11 :             for (int j = 0; j < 10; ++j) {
    1160         [ +  - ]:          10 :                 add_coin(available_coins, wallet, CAmount(1 * COIN), CFeeRate(5000), 144, false, 0, true);
    1161         [ +  - ]:          10 :                 add_coin(available_coins, wallet, CAmount(2 * COIN), CFeeRate(5000), 144, false, 0, true);
    1162                 :             :             }
    1163                 :           1 :             return available_coins;
    1164         [ +  - ]:           1 :         });
    1165   [ +  -  +  -  :           2 :         BOOST_CHECK(!res);
                   +  - ]
    1166   [ +  -  +  -  :           3 :         BOOST_CHECK(util::ErrorString(res).original.find("The inputs size exceeds the maximum weight") != std::string::npos);
                   +  - ]
    1167                 :           0 :     }
    1168                 :             : 
    1169                 :           1 :     {
    1170                 :             :         // ###############################################################################################################
    1171                 :             :         // 3) Test selection when some coins surpass the max allowed weight while others not. --> must find a good solution
    1172                 :             :         // ################################################################################################################
    1173                 :           1 :         CAmount target = 25.33L * COIN;
    1174                 :           1 :         int max_selection_weight = 10'000; // WU
    1175         [ +  - ]:           2 :         const auto& res = CoinGrinder(target, dummy_params, m_node, max_selection_weight, [&](CWallet& wallet) {
    1176                 :           1 :             CoinsResult available_coins;
    1177         [ +  + ]:          61 :             for (int j = 0; j < 60; ++j) { // 60 UTXO --> 19,8 BTC total --> 60 × 272 WU = 16320 WU
    1178         [ +  - ]:          60 :                 add_coin(available_coins, wallet, CAmount(0.33 * COIN), CFeeRate(5000), 144, false, 0, true);
    1179                 :             :             }
    1180         [ +  + ]:          11 :             for (int i = 0; i < 10; i++) { // 10 UTXO --> 20 BTC total --> 10 × 272 WU = 2720 WU
    1181         [ +  - ]:          10 :                 add_coin(available_coins, wallet, CAmount(2 * COIN), CFeeRate(5000), 144, false, 0, true);
    1182                 :             :             }
    1183                 :           1 :             return available_coins;
    1184         [ +  - ]:           1 :         });
    1185   [ +  -  +  -  :           2 :         BOOST_CHECK(res);
                   +  - ]
    1186                 :             :         // Demonstrate how following improvements reduce iteration count and catch any regressions in the future.
    1187                 :           1 :         size_t expected_attempts = 37;
    1188   [ +  -  +  -  :           2 :         BOOST_CHECK_MESSAGE(res->GetSelectionsEvaluated() == expected_attempts, strprintf("Expected %i attempts, but got %i", expected_attempts, res->GetSelectionsEvaluated()));
          +  -  +  -  +  
                      - ]
    1189                 :           0 :     }
    1190                 :             : 
    1191                 :           1 :     {
    1192                 :             :         // #################################################################################################################
    1193                 :             :         // 4) Test that two less valuable UTXOs with a combined lower weight are preferred over a more valuable heavier UTXO
    1194                 :             :         // #################################################################################################################
    1195                 :           1 :         CAmount target =  1.9L * COIN;
    1196                 :           1 :         int max_selection_weight = 400'000; // WU
    1197         [ +  - ]:           2 :         const auto& res = CoinGrinder(target, dummy_params, m_node, max_selection_weight, [&](CWallet& wallet) {
    1198         [ +  - ]:           1 :             CoinsResult available_coins;
    1199         [ +  - ]:           1 :             add_coin(available_coins, wallet, CAmount(2 * COIN), CFeeRate(5000), 144, false, 0, true, 148);
    1200         [ +  - ]:           1 :             add_coin(available_coins, wallet, CAmount(1 * COIN), CFeeRate(5000), 144, false, 0, true, 68);
    1201         [ +  - ]:           1 :             add_coin(available_coins, wallet, CAmount(1 * COIN), CFeeRate(5000), 144, false, 0, true, 68);
    1202                 :           1 :             return available_coins;
    1203         [ +  - ]:           1 :         });
    1204         [ +  - ]:           1 :         SelectionResult expected_result(CAmount(0), SelectionAlgorithm::CG);
    1205         [ +  - ]:           1 :         add_coin(1 * COIN, 1, expected_result);
    1206         [ +  - ]:           1 :         add_coin(1 * COIN, 2, expected_result);
    1207   [ +  -  +  -  :           2 :         BOOST_CHECK(EquivalentResult(expected_result, *res));
             +  -  +  - ]
    1208                 :             :         // Demonstrate how following improvements reduce iteration count and catch any regressions in the future.
    1209                 :           1 :         size_t expected_attempts = 3;
    1210   [ +  -  +  -  :           2 :         BOOST_CHECK_MESSAGE(res->GetSelectionsEvaluated() == expected_attempts, strprintf("Expected %i attempts, but got %i", expected_attempts, res->GetSelectionsEvaluated()));
          +  -  +  -  +  
                      - ]
    1211                 :           1 :     }
    1212                 :             : 
    1213                 :           1 :     {
    1214                 :             :         // ###############################################################################################################
    1215                 :             :         // 5) Test finding a solution in a UTXO pool with mixed weights
    1216                 :             :         // ################################################################################################################
    1217                 :           1 :         CAmount target = 30L * COIN;
    1218                 :           1 :         int max_selection_weight = 400'000; // WU
    1219         [ +  - ]:           2 :         const auto& res = CoinGrinder(target, dummy_params, m_node, max_selection_weight, [&](CWallet& wallet) {
    1220                 :           1 :             CoinsResult available_coins;
    1221         [ +  + ]:           6 :             for (int j = 0; j < 5; ++j) {
    1222                 :             :                 // Add heavy coins {3, 6, 9, 12, 15}
    1223         [ +  - ]:           5 :                 add_coin(available_coins, wallet, CAmount((3 + 3 * j) * COIN), CFeeRate(5000), 144, false, 0, true, 350);
    1224                 :             :                 // Add medium coins {2, 5, 8, 11, 14}
    1225         [ +  - ]:           5 :                 add_coin(available_coins, wallet, CAmount((2 + 3 * j) * COIN), CFeeRate(5000), 144, false, 0, true, 250);
    1226                 :             :                 // Add light coins {1, 4, 7, 10, 13}
    1227         [ +  - ]:           5 :                 add_coin(available_coins, wallet, CAmount((1 + 3 * j) * COIN), CFeeRate(5000), 144, false, 0, true, 150);
    1228                 :             :             }
    1229                 :           1 :             return available_coins;
    1230         [ +  - ]:           1 :         });
    1231   [ +  -  +  -  :           2 :         BOOST_CHECK(res);
                   +  - ]
    1232         [ +  - ]:           1 :         SelectionResult expected_result(CAmount(0), SelectionAlgorithm::CG);
    1233         [ +  - ]:           1 :         add_coin(14 * COIN, 1, expected_result);
    1234         [ +  - ]:           1 :         add_coin(13 * COIN, 2, expected_result);
    1235         [ +  - ]:           1 :         add_coin(4 * COIN, 3, expected_result);
    1236   [ +  -  +  -  :           2 :         BOOST_CHECK(EquivalentResult(expected_result, *res));
             +  -  +  - ]
    1237                 :             :         // Demonstrate how following improvements reduce iteration count and catch any regressions in the future.
    1238                 :           1 :         size_t expected_attempts = 92;
    1239   [ +  -  +  -  :           2 :         BOOST_CHECK_MESSAGE(res->GetSelectionsEvaluated() == expected_attempts, strprintf("Expected %i attempts, but got %i", expected_attempts, res->GetSelectionsEvaluated()));
          +  -  +  -  +  
                      - ]
    1240                 :           1 :     }
    1241                 :             : 
    1242                 :           1 :     {
    1243                 :             :         // #################################################################################################################
    1244                 :             :         // 6) Test that the lightest solution among many clones is found
    1245                 :             :         // #################################################################################################################
    1246                 :           1 :         CAmount target =  9.9L * COIN;
    1247                 :           1 :         int max_selection_weight = 400'000; // WU
    1248         [ +  - ]:           2 :         const auto& res = CoinGrinder(target, dummy_params, m_node, max_selection_weight, [&](CWallet& wallet) {
    1249         [ +  - ]:           1 :             CoinsResult available_coins;
    1250                 :             :             // Expected Result: 4 + 3 + 2 + 1 = 10 BTC at 400 vB
    1251         [ +  - ]:           1 :             add_coin(available_coins, wallet, CAmount(4 * COIN), CFeeRate(5000), 144, false, 0, true, 100);
    1252         [ +  - ]:           1 :             add_coin(available_coins, wallet, CAmount(3 * COIN), CFeeRate(5000), 144, false, 0, true, 100);
    1253         [ +  - ]:           1 :             add_coin(available_coins, wallet, CAmount(2 * COIN), CFeeRate(5000), 144, false, 0, true, 100);
    1254         [ +  - ]:           1 :             add_coin(available_coins, wallet, CAmount(1 * COIN), CFeeRate(5000), 144, false, 0, true, 100);
    1255                 :             :             // Distracting clones:
    1256         [ +  + ]:         101 :             for (int j = 0; j < 100; ++j) {
    1257         [ +  - ]:         100 :                 add_coin(available_coins, wallet, CAmount(8 * COIN), CFeeRate(5000), 144, false, 0, true, 1000);
    1258                 :             :             }
    1259         [ +  + ]:         101 :             for (int j = 0; j < 100; ++j) {
    1260         [ +  - ]:         100 :                 add_coin(available_coins, wallet, CAmount(7 * COIN), CFeeRate(5000), 144, false, 0, true, 800);
    1261                 :             :             }
    1262         [ +  + ]:         101 :             for (int j = 0; j < 100; ++j) {
    1263         [ +  - ]:         100 :                 add_coin(available_coins, wallet, CAmount(6 * COIN), CFeeRate(5000), 144, false, 0, true, 600);
    1264                 :             :             }
    1265         [ +  + ]:         101 :             for (int j = 0; j < 100; ++j) {
    1266         [ +  - ]:         100 :                 add_coin(available_coins, wallet, CAmount(5 * COIN), CFeeRate(5000), 144, false, 0, true, 400);
    1267                 :             :             }
    1268                 :           1 :             return available_coins;
    1269         [ +  - ]:           1 :         });
    1270         [ +  - ]:           1 :         SelectionResult expected_result(CAmount(0), SelectionAlgorithm::CG);
    1271         [ +  - ]:           1 :         add_coin(4 * COIN, 0, expected_result);
    1272         [ +  - ]:           1 :         add_coin(3 * COIN, 0, expected_result);
    1273         [ +  - ]:           1 :         add_coin(2 * COIN, 0, expected_result);
    1274         [ +  - ]:           1 :         add_coin(1 * COIN, 0, expected_result);
    1275   [ +  -  +  -  :           2 :         BOOST_CHECK(EquivalentResult(expected_result, *res));
             +  -  +  - ]
    1276                 :             :         // Demonstrate how following improvements reduce iteration count and catch any regressions in the future.
    1277                 :           1 :         size_t expected_attempts = 38;
    1278   [ +  -  +  -  :           2 :         BOOST_CHECK_MESSAGE(res->GetSelectionsEvaluated() == expected_attempts, strprintf("Expected %i attempts, but got %i", expected_attempts, res->GetSelectionsEvaluated()));
          +  -  +  -  +  
                      - ]
    1279                 :           1 :     }
    1280                 :             : 
    1281                 :           1 :     {
    1282                 :             :         // #################################################################################################################
    1283                 :             :         // 7) Test that lots of tiny UTXOs can be skipped if they are too heavy while there are enough funds in lookahead
    1284                 :             :         // #################################################################################################################
    1285                 :           1 :         CAmount target =  1.9L * COIN;
    1286                 :           1 :         int max_selection_weight = 40000; // WU
    1287         [ +  - ]:           2 :         const auto& res = CoinGrinder(target, dummy_params, m_node, max_selection_weight, [&](CWallet& wallet) {
    1288         [ +  - ]:           1 :             CoinsResult available_coins;
    1289         [ +  - ]:           1 :             add_coin(available_coins, wallet, CAmount(1.8 * COIN), CFeeRate(5000), 144, false, 0, true, 2500);
    1290         [ +  - ]:           1 :             add_coin(available_coins, wallet, CAmount(1 * COIN), CFeeRate(5000), 144, false, 0, true, 1000);
    1291         [ +  - ]:           1 :             add_coin(available_coins, wallet, CAmount(1 * COIN), CFeeRate(5000), 144, false, 0, true, 1000);
    1292         [ +  + ]:         101 :             for (int j = 0; j < 100; ++j) {
    1293                 :             :                 // make a 100 unique coins only differing by one sat
    1294         [ +  - ]:         100 :                 add_coin(available_coins, wallet, CAmount(0.01 * COIN + j), CFeeRate(5000), 144, false, 0, true, 110);
    1295                 :             :             }
    1296                 :           1 :             return available_coins;
    1297         [ +  - ]:           1 :         });
    1298         [ +  - ]:           1 :         SelectionResult expected_result(CAmount(0), SelectionAlgorithm::CG);
    1299         [ +  - ]:           1 :         add_coin(1 * COIN, 1, expected_result);
    1300         [ +  - ]:           1 :         add_coin(1 * COIN, 2, expected_result);
    1301   [ +  -  +  -  :           2 :         BOOST_CHECK(EquivalentResult(expected_result, *res));
             +  -  +  - ]
    1302                 :             :         // Demonstrate how following improvements reduce iteration count and catch any regressions in the future.
    1303                 :           1 :         size_t expected_attempts = 7;
    1304   [ +  -  +  -  :           2 :         BOOST_CHECK_MESSAGE(res->GetSelectionsEvaluated() == expected_attempts, strprintf("Expected %i attempts, but got %i", expected_attempts, res->GetSelectionsEvaluated()));
          +  -  +  -  +  
                      - ]
    1305                 :           1 :     }
    1306                 :           1 : }
    1307                 :             : 
    1308                 :           3 : static util::Result<SelectionResult> SelectCoinsSRD(const CAmount& target,
    1309                 :             :                                                     const CoinSelectionParams& cs_params,
    1310                 :             :                                                     const node::NodeContext& m_node,
    1311                 :             :                                                     int max_selection_weight,
    1312                 :             :                                                     std::function<CoinsResult(CWallet&)> coin_setup)
    1313                 :             : {
    1314         [ +  - ]:           3 :     std::unique_ptr<CWallet> wallet = NewWallet(m_node);
    1315         [ +  - ]:           3 :     CoinEligibilityFilter filter(0, 0, 0); // accept all coins without ancestors
    1316   [ +  -  +  -  :           6 :     Groups group = GroupOutputs(*wallet, coin_setup(*wallet), cs_params, {{filter}})[filter].all_groups;
          +  -  +  -  +  
                -  +  - ]
    1317         [ +  - ]:           3 :     return SelectCoinsSRD(group.positive_group, target, cs_params.m_change_fee, cs_params.rng_fast, max_selection_weight);
    1318         [ +  - ]:           6 : }
    1319                 :             : 
    1320   [ +  -  +  -  :           7 : BOOST_AUTO_TEST_CASE(srd_tests)
          +  -  +  -  +  
          -  +  -  +  -  
          +  -  +  -  +  
          -  +  -  +  -  
          +  -  +  -  +  
          -  +  -  +  -  
          +  -  +  -  +  
          -  +  -  +  -  
          +  -  +  -  +  
          -  +  -  +  -  
          +  -  +  -  +  
                      - ]
    1321                 :             : {
    1322                 :             :     // Test SRD:
    1323                 :             :     // 1) Insufficient funds, select all provided coins and fail.
    1324                 :             :     // 2) Exceeded max weight, coin selection always surpasses the max allowed weight.
    1325                 :             :     // 3) Select coins without surpassing the max weight (some coins surpasses the max allowed weight, some others not)
    1326                 :             : 
    1327                 :           1 :     FastRandomContext rand;
    1328         [ +  - ]:           1 :     CoinSelectionParams dummy_params{ // Only used to provide the 'avoid_partial' flag.
    1329                 :             :             rand,
    1330                 :             :             /*change_output_size=*/34,
    1331                 :             :             /*change_spend_size=*/68,
    1332                 :             :             /*min_change_target=*/CENT,
    1333                 :           1 :             /*effective_feerate=*/CFeeRate(0),
    1334                 :           1 :             /*long_term_feerate=*/CFeeRate(0),
    1335         [ +  - ]:           1 :             /*discard_feerate=*/CFeeRate(0),
    1336                 :             :             /*tx_noinputs_size=*/10 + 34, // static header size + output size
    1337                 :             :             /*avoid_partial=*/false,
    1338                 :           1 :     };
    1339                 :             : 
    1340                 :           1 :     {
    1341                 :             :         // #########################################################
    1342                 :             :         // 1) Insufficient funds, select all provided coins and fail
    1343                 :             :         // #########################################################
    1344                 :           1 :         CAmount target = 49.5L * COIN;
    1345                 :           1 :         int max_selection_weight = 10000; // high enough to not fail for this reason.
    1346         [ +  - ]:           2 :         const auto& res = SelectCoinsSRD(target, dummy_params, m_node, max_selection_weight, [&](CWallet& wallet) {
    1347                 :           1 :             CoinsResult available_coins;
    1348         [ +  + ]:          11 :             for (int j = 0; j < 10; ++j) {
    1349         [ +  - ]:          10 :                 add_coin(available_coins, wallet, CAmount(1 * COIN));
    1350         [ +  - ]:          10 :                 add_coin(available_coins, wallet, CAmount(2 * COIN));
    1351                 :             :             }
    1352                 :           1 :             return available_coins;
    1353         [ +  - ]:           1 :         });
    1354   [ +  -  +  -  :           2 :         BOOST_CHECK(!res);
                   +  - ]
    1355   [ +  -  +  -  :           3 :         BOOST_CHECK(util::ErrorString(res).empty()); // empty means "insufficient funds"
                   +  - ]
    1356                 :           0 :     }
    1357                 :             : 
    1358                 :           1 :     {
    1359                 :             :         // ###########################
    1360                 :             :         // 2) Test max weight exceeded
    1361                 :             :         // ###########################
    1362                 :           1 :         CAmount target = 49.5L * COIN;
    1363                 :           1 :         int max_selection_weight = 3000;
    1364         [ +  - ]:           2 :         const auto& res = SelectCoinsSRD(target, dummy_params, m_node, max_selection_weight, [&](CWallet& wallet) {
    1365                 :           1 :             CoinsResult available_coins;
    1366         [ +  + ]:          11 :             for (int j = 0; j < 10; ++j) {
    1367                 :             :                 /* 10 × 1 BTC + 10 × 2 BTC = 30 BTC. 20 × 272 WU = 5440 WU */
    1368         [ +  - ]:          10 :                 add_coin(available_coins, wallet, CAmount(1 * COIN), CFeeRate(0), 144, false, 0, true);
    1369         [ +  - ]:          10 :                 add_coin(available_coins, wallet, CAmount(2 * COIN), CFeeRate(0), 144, false, 0, true);
    1370                 :             :             }
    1371                 :           1 :             return available_coins;
    1372         [ +  - ]:           1 :         });
    1373   [ +  -  +  -  :           2 :         BOOST_CHECK(!res);
                   +  - ]
    1374   [ +  -  +  -  :           3 :         BOOST_CHECK(util::ErrorString(res).original.find("The inputs size exceeds the maximum weight") != std::string::npos);
                   +  - ]
    1375                 :           0 :     }
    1376                 :             : 
    1377                 :           1 :     {
    1378                 :             :         // ################################################################################################################
    1379                 :             :         // 3) Test selection when some coins surpass the max allowed weight while others not. --> must find a good solution
    1380                 :             :         // ################################################################################################################
    1381                 :           1 :         CAmount target = 25.33L * COIN;
    1382                 :           1 :         int max_selection_weight = 10000; // WU
    1383         [ +  - ]:           2 :         const auto& res = SelectCoinsSRD(target, dummy_params, m_node, max_selection_weight, [&](CWallet& wallet) {
    1384                 :           1 :             CoinsResult available_coins;
    1385         [ +  + ]:          61 :             for (int j = 0; j < 60; ++j) { // 60 UTXO --> 19,8 BTC total --> 60 × 272 WU = 16320 WU
    1386         [ +  - ]:          60 :                 add_coin(available_coins, wallet, CAmount(0.33 * COIN), CFeeRate(0), 144, false, 0, true);
    1387                 :             :             }
    1388         [ +  + ]:          11 :             for (int i = 0; i < 10; i++) { // 10 UTXO --> 20 BTC total --> 10 × 272 WU = 2720 WU
    1389         [ +  - ]:          10 :                 add_coin(available_coins, wallet, CAmount(2 * COIN), CFeeRate(0), 144, false, 0, true);
    1390                 :             :             }
    1391                 :           1 :             return available_coins;
    1392         [ +  - ]:           1 :         });
    1393   [ +  -  +  - ]:           2 :         BOOST_CHECK(res);
    1394                 :           1 :     }
    1395                 :           1 : }
    1396                 :             : 
    1397                 :           3 : static util::Result<SelectionResult> select_coins(const CAmount& target, const CoinSelectionParams& cs_params, const CCoinControl& cc, std::function<CoinsResult(CWallet&)> coin_setup, const node::NodeContext& m_node)
    1398                 :             : {
    1399         [ +  - ]:           3 :     std::unique_ptr<CWallet> wallet = NewWallet(m_node);
    1400         [ +  - ]:           3 :     auto available_coins = coin_setup(*wallet);
    1401                 :             : 
    1402         [ +  - ]:           3 :     LOCK(wallet->cs_wallet);
    1403                 :           0 :     auto result = SelectCoins(*wallet, available_coins, /*pre_set_inputs=*/ {}, target, cc, cs_params);
    1404         [ +  + ]:           3 :     if (result) {
    1405   [ +  -  +  - ]:           2 :         const auto signedTxSize = 10 + 34 + 68 * result->GetInputSet().size(); // static header size + output size + inputs size (P2WPKH)
    1406   [ +  -  +  - ]:           2 :         BOOST_CHECK_LE(signedTxSize * WITNESS_SCALE_FACTOR, MAX_STANDARD_TX_WEIGHT);
    1407                 :             : 
    1408   [ +  -  +  -  :           2 :         BOOST_CHECK_GE(result->GetSelectedValue(), target);
                   +  - ]
    1409                 :             :     }
    1410         [ +  - ]:           3 :     return result;
    1411   [ +  -  +  - ]:           9 : }
    1412                 :             : 
    1413                 :           3 : static bool has_coin(const CoinSet& set, CAmount amount)
    1414                 :             : {
    1415         [ +  + ]:          25 :     return std::any_of(set.begin(), set.end(), [&](const auto& coin) { return coin->GetEffectiveValue() == amount; });
    1416                 :             : }
    1417                 :             : 
    1418   [ +  -  +  -  :           7 : BOOST_AUTO_TEST_CASE(check_max_selection_weight)
          +  -  +  -  +  
          -  +  -  +  -  
          +  -  +  -  +  
          -  +  -  +  -  
          +  -  +  -  +  
          -  +  -  +  -  
          +  -  +  -  +  
          -  +  -  +  -  
          +  -  +  -  +  
          -  +  -  +  -  
          +  -  +  -  +  
                      - ]
    1419                 :             : {
    1420                 :           1 :     const CAmount target = 49.5L * COIN;
    1421                 :           1 :     CCoinControl cc;
    1422                 :             : 
    1423                 :           1 :     FastRandomContext rand;
    1424         [ +  - ]:           1 :     CoinSelectionParams cs_params{
    1425                 :             :         rand,
    1426                 :             :         /*change_output_size=*/34,
    1427                 :             :         /*change_spend_size=*/68,
    1428                 :             :         /*min_change_target=*/CENT,
    1429                 :           1 :         /*effective_feerate=*/CFeeRate(0),
    1430                 :           1 :         /*long_term_feerate=*/CFeeRate(0),
    1431         [ +  - ]:           1 :         /*discard_feerate=*/CFeeRate(0),
    1432                 :             :         /*tx_noinputs_size=*/10 + 34, // static header size + output size
    1433                 :             :         /*avoid_partial=*/false,
    1434                 :           1 :     };
    1435                 :             : 
    1436                 :           1 :     int max_weight = MAX_STANDARD_TX_WEIGHT - WITNESS_SCALE_FACTOR * (cs_params.tx_noinputs_size + cs_params.change_output_size);
    1437                 :           1 :     {
    1438                 :             :         // Scenario 1:
    1439                 :             :         // The actor starts with 1x 50.0 BTC and 1515x 0.033 BTC (~100.0 BTC total) unspent outputs
    1440                 :             :         // Then tries to spend 49.5 BTC
    1441                 :             :         // The 50.0 BTC output should be selected, because the transaction would otherwise be too large
    1442                 :             : 
    1443                 :             :         // Perform selection
    1444                 :             : 
    1445                 :           0 :         const auto result = select_coins(
    1446                 :           1 :             target, cs_params, cc, [&](CWallet& wallet) {
    1447                 :           1 :                 CoinsResult available_coins;
    1448         [ +  + ]:        1516 :                 for (int j = 0; j < 1515; ++j) {
    1449         [ +  - ]:        1515 :                     add_coin(available_coins, wallet, CAmount(0.033 * COIN), CFeeRate(0), 144, false, 0, true);
    1450                 :             :                 }
    1451                 :             : 
    1452         [ +  - ]:           1 :                 add_coin(available_coins, wallet, CAmount(50 * COIN), CFeeRate(0), 144, false, 0, true);
    1453                 :           1 :                 return available_coins;
    1454                 :           0 :             },
    1455         [ +  - ]:           1 :             m_node);
    1456                 :             : 
    1457   [ +  -  +  -  :           2 :         BOOST_CHECK(result);
                   +  - ]
    1458                 :             :         // Verify that the 50 BTC UTXO was selected, and result is below max_weight
    1459   [ +  -  +  -  :           2 :         BOOST_CHECK(has_coin(result->GetInputSet(), CAmount(50 * COIN)));
             +  -  +  - ]
    1460   [ +  -  +  - ]:           1 :         BOOST_CHECK_LE(result->GetWeight(), max_weight);
    1461                 :           0 :     }
    1462                 :             : 
    1463                 :           1 :     {
    1464                 :             :         // Scenario 2:
    1465                 :             : 
    1466                 :             :         // The actor starts with 400x 0.0625 BTC and 2000x 0.025 BTC (75.0 BTC total) unspent outputs
    1467                 :             :         // Then tries to spend 49.5 BTC
    1468                 :             :         // A combination of coins should be selected, such that the created transaction is not too large
    1469                 :             : 
    1470                 :             :         // Perform selection
    1471                 :           0 :         const auto result = select_coins(
    1472                 :           1 :             target, cs_params, cc, [&](CWallet& wallet) {
    1473                 :           1 :                 CoinsResult available_coins;
    1474         [ +  + ]:         401 :                 for (int j = 0; j < 400; ++j) {
    1475         [ +  - ]:         400 :                     add_coin(available_coins, wallet, CAmount(0.0625 * COIN), CFeeRate(0), 144, false, 0, true);
    1476                 :             :                 }
    1477         [ +  + ]:        2001 :                 for (int j = 0; j < 2000; ++j) {
    1478         [ +  - ]:        2000 :                     add_coin(available_coins, wallet, CAmount(0.025 * COIN), CFeeRate(0), 144, false, 0, true);
    1479                 :             :                 }
    1480                 :           1 :                 return available_coins;
    1481                 :           0 :             },
    1482         [ +  - ]:           1 :             m_node);
    1483                 :             : 
    1484   [ +  -  +  -  :           2 :         BOOST_CHECK(has_coin(result->GetInputSet(), CAmount(0.0625 * COIN)));
             +  -  +  - ]
    1485   [ +  -  +  -  :           2 :         BOOST_CHECK(has_coin(result->GetInputSet(), CAmount(0.025 * COIN)));
             +  -  +  - ]
    1486   [ +  -  +  - ]:           1 :         BOOST_CHECK_LE(result->GetWeight(), max_weight);
    1487                 :           0 :     }
    1488                 :             : 
    1489                 :           1 :     {
    1490                 :             :         // Scenario 3:
    1491                 :             : 
    1492                 :             :         // The actor starts with 1515x 0.033 BTC (49.995 BTC total) unspent outputs
    1493                 :             :         // No results should be returned, because the transaction would be too large
    1494                 :             : 
    1495                 :             :         // Perform selection
    1496                 :           0 :         const auto result = select_coins(
    1497                 :           1 :             target, cs_params, cc, [&](CWallet& wallet) {
    1498                 :           1 :                 CoinsResult available_coins;
    1499         [ +  + ]:        1516 :                 for (int j = 0; j < 1515; ++j) {
    1500         [ +  - ]:        1515 :                     add_coin(available_coins, wallet, CAmount(0.033 * COIN), CFeeRate(0), 144, false, 0, true);
    1501                 :             :                 }
    1502                 :           1 :                 return available_coins;
    1503                 :           0 :             },
    1504         [ +  - ]:           1 :             m_node);
    1505                 :             : 
    1506                 :             :         // No results
    1507                 :             :         // 1515 inputs * 68 bytes = 103,020 bytes
    1508                 :             :         // 103,020 bytes * 4 = 412,080 weight, which is above the MAX_STANDARD_TX_WEIGHT of 400,000
    1509   [ +  -  +  - ]:           2 :         BOOST_CHECK(!result);
    1510                 :           1 :     }
    1511                 :           1 : }
    1512                 :             : 
    1513   [ +  -  +  -  :           7 : BOOST_AUTO_TEST_CASE(SelectCoins_effective_value_test)
          +  -  +  -  +  
          -  +  -  +  -  
          +  -  +  -  +  
          -  +  -  +  -  
          +  -  +  -  +  
          -  +  -  +  -  
          +  -  +  -  +  
          -  +  -  +  -  
          +  -  +  -  +  
          -  +  -  +  -  
          +  -  +  -  +  
                      - ]
    1514                 :             : {
    1515                 :             :     // Test that the effective value is used to check whether preset inputs provide sufficient funds when subtract_fee_outputs is not used.
    1516                 :             :     // This test creates a coin whose value is higher than the target but whose effective value is lower than the target.
    1517                 :             :     // The coin is selected using coin control, with m_allow_other_inputs = false. SelectCoins should fail due to insufficient funds.
    1518                 :             : 
    1519         [ +  - ]:           1 :     std::unique_ptr<CWallet> wallet = NewWallet(m_node);
    1520                 :             : 
    1521         [ +  - ]:           1 :     CoinsResult available_coins;
    1522                 :           1 :     {
    1523   [ +  -  +  - ]:           1 :         std::unique_ptr<CWallet> dummyWallet = NewWallet(m_node, /*wallet_name=*/"dummy");
    1524         [ +  - ]:           1 :         add_coin(available_coins, *dummyWallet, 100000); // 0.001 BTC
    1525                 :           0 :     }
    1526                 :             : 
    1527                 :           1 :     CAmount target{99900}; // 0.000999 BTC
    1528                 :             : 
    1529                 :           1 :     FastRandomContext rand;
    1530         [ +  - ]:           1 :     CoinSelectionParams cs_params{
    1531                 :             :         rand,
    1532                 :             :         /*change_output_size=*/34,
    1533                 :             :         /*change_spend_size=*/148,
    1534                 :             :         /*min_change_target=*/1000,
    1535                 :           1 :         /*effective_feerate=*/CFeeRate(3000),
    1536                 :           1 :         /*long_term_feerate=*/CFeeRate(1000),
    1537         [ +  - ]:           1 :         /*discard_feerate=*/CFeeRate(1000),
    1538                 :             :         /*tx_noinputs_size=*/0,
    1539                 :             :         /*avoid_partial=*/false,
    1540                 :           1 :     };
    1541         [ +  - ]:           1 :     CCoinControl cc;
    1542                 :           1 :     cc.m_allow_other_inputs = false;
    1543         [ +  - ]:           2 :     COutput output = available_coins.All().at(0);
    1544         [ +  - ]:           1 :     cc.SetInputWeight(output.outpoint, 148);
    1545   [ +  -  +  - ]:           1 :     cc.Select(output.outpoint).SetTxOut(output.txout);
    1546                 :             : 
    1547         [ +  - ]:           1 :     LOCK(wallet->cs_wallet);
    1548   [ +  -  +  -  :           1 :     const auto preset_inputs = *Assert(FetchSelectedInputs(*wallet, cc, cs_params));
                   +  - ]
    1549   [ +  -  +  -  :           3 :     available_coins.Erase({available_coins.coins[OutputType::BECH32].begin()->outpoint});
             +  -  +  - ]
    1550                 :             : 
    1551         [ +  - ]:           1 :     const auto result = SelectCoins(*wallet, available_coins, preset_inputs, target, cc, cs_params);
    1552   [ +  -  +  - ]:           2 :     BOOST_CHECK(!result);
    1553   [ +  -  +  - ]:           3 : }
    1554                 :             : 
    1555   [ +  -  +  -  :           7 : BOOST_FIXTURE_TEST_CASE(wallet_coinsresult_test, BasicTestingSetup)
          +  -  +  -  +  
          -  +  -  +  -  
          +  -  +  -  +  
          -  +  -  +  -  
          +  -  +  -  +  
          -  +  -  +  -  
          +  -  +  -  +  
          -  +  -  +  -  
          +  -  +  -  +  
          -  +  -  +  -  
          +  -  +  -  +  
                      - ]
    1556                 :             : {
    1557                 :             :     // Test case to verify CoinsResult object sanity.
    1558         [ +  - ]:           1 :     CoinsResult available_coins;
    1559                 :           1 :     {
    1560   [ +  -  +  - ]:           1 :         std::unique_ptr<CWallet> dummyWallet = NewWallet(m_node, /*wallet_name=*/"dummy");
    1561                 :             : 
    1562                 :             :         // Add some coins to 'available_coins'
    1563         [ +  + ]:          11 :         for (int i=0; i<10; i++) {
    1564         [ +  - ]:          10 :             add_coin(available_coins, *dummyWallet, 1 * COIN);
    1565                 :             :         }
    1566                 :           0 :     }
    1567                 :             : 
    1568                 :           1 :     {
    1569                 :             :         // First test case, check that 'CoinsResult::Erase' function works as expected.
    1570                 :             :         // By trying to erase two elements from the 'available_coins' object.
    1571         [ +  - ]:           1 :         std::unordered_set<COutPoint, SaltedOutpointHasher> outs_to_remove;
    1572         [ +  - ]:           1 :         const auto& coins = available_coins.All();
    1573         [ +  + ]:           3 :         for (int i = 0; i < 2; i++) {
    1574         [ +  - ]:           2 :             outs_to_remove.emplace(coins[i].outpoint);
    1575                 :             :         }
    1576         [ +  - ]:           1 :         available_coins.Erase(outs_to_remove);
    1577                 :             : 
    1578                 :             :         // Check that the elements were actually removed.
    1579         [ +  - ]:           1 :         const auto& updated_coins = available_coins.All();
    1580         [ +  + ]:           3 :         for (const auto& out: outs_to_remove) {
    1581         [ +  - ]:          18 :             auto it = std::find_if(updated_coins.begin(), updated_coins.end(), [&out](const COutput &coin) {
    1582   [ -  +  -  +  :           4 :                 return coin.outpoint == out;
          -  +  -  +  -  
             -  -  -  -  
                      - ]
    1583                 :             :             });
    1584   [ +  -  +  - ]:           4 :             BOOST_CHECK(it == updated_coins.end());
    1585                 :             :         }
    1586                 :             :         // And verify that no extra element were removed
    1587   [ +  -  +  -  :           1 :         BOOST_CHECK_EQUAL(available_coins.Size(), 8);
                   +  - ]
    1588                 :           1 :     }
    1589                 :           1 : }
    1590                 :             : 
    1591                 :             : BOOST_AUTO_TEST_SUITE_END()
    1592                 :             : } // namespace wallet
        

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