tests: Remove global vCoins and testWallet from coinselector_tests

To avoid issues with test data leaking across tests cases, the global
vCoins and testWallet are removed from coinselector_tests and all of the
relevant functions reworked to not need them.

1 files changed, 196 insertions, 201 deletions

diff --git a/src/wallet/test/coinselector_tests.cpp b/src/wallet/test/coinselector_tests.cpp
index f80c4637b8..6b4c2a2725 100644
--- a/src/wallet/test/coinselector_tests.cpp
+++ b/src/wallet/test/coinselector_tests.cpp
@@ -28,19 +28,9 @@ BOOST_FIXTURE_TEST_SUITE(coinselector_tests, WalletTestingSetup)
 
 typedef std::set<CInputCoin> CoinSet;
 
-static std::vector<COutput> vCoins;
-static NodeContext testNode;
-static auto testChain = interfaces::MakeChain(testNode);
-static CWallet testWallet(testChain.get(), "", CreateDummyWalletDatabase());
-static CAmount balance = 0;
-
-CoinEligibilityFilter filter_standard(1, 6, 0);
-CoinEligibilityFilter filter_confirmed(1, 1, 0);
-CoinEligibilityFilter filter_standard_extra(6, 6, 0);
-CoinSelectionParams coin_selection_params(/* change_output_size= */ 0,
-                                          /* change_spend_size= */ 0, /* effective_feerate= */ CFeeRate(0),
-                                          /* long_term_feerate= */ CFeeRate(0), /* discard_feerate= */ CFeeRate(0),
-                                          /* tx_noinputs_size= */ 0, /* avoid_partial= */ false);
+static const CoinEligibilityFilter filter_standard(1, 6, 0);
+static const CoinEligibilityFilter filter_confirmed(1, 1, 0);
+static const CoinEligibilityFilter filter_standard_extra(6, 6, 0);
 
 static void add_coin(const CAmount& nValue, int nInput, std::vector<CInputCoin>& set)
 {
@@ -62,9 +52,8 @@ static void add_coin(const CAmount& nValue, int nInput, CoinSet& set, CAmount fe
     set.insert(coin);
 }
 
-static void add_coin(CWallet& wallet, const CAmount& nValue, int nAge = 6*24, bool fIsFromMe = false, int nInput=0, bool spendable = false)
+static void add_coin(std::vector<COutput>& coins, CWallet& wallet, const CAmount& nValue, int nAge = 6*24, bool fIsFromMe = false, int nInput=0, bool spendable = false)
 {
-    balance += nValue;
     static int nextLockTime = 0;
     CMutableTransaction tx;
     tx.nLockTime = nextLockTime++;        // so all transactions get different hashes
@@ -89,17 +78,7 @@ static void add_coin(CWallet& wallet, const CAmount& nValue, int nAge = 6*24, bo
         wtx->m_is_cache_empty = false;
     }
     COutput output(wallet, *wtx, nInput, nAge, true /* spendable */, true /* solvable */, true /* safe */);
-    vCoins.push_back(output);
-}
-static void add_coin(const CAmount& nValue, int nAge = 6*24, bool fIsFromMe = false, int nInput=0, bool spendable = false)
-{
-    add_coin(testWallet, nValue, nAge, fIsFromMe, nInput, spendable);
-}
-
-static void empty_wallet(void)
-{
-    vCoins.clear();
-    balance = 0;
+    coins.push_back(output);
 }
 
 static bool equal_sets(CoinSet a, CoinSet b)
@@ -142,20 +121,20 @@ inline std::vector<OutputGroup>& GroupCoins(const std::vector<COutput>& coins)
     return static_groups;
 }
 
-inline std::vector<OutputGroup>& KnapsackGroupOutputs(const CoinEligibilityFilter& filter)
+inline std::vector<OutputGroup>& KnapsackGroupOutputs(const std::vector<COutput>& coins, CWallet& wallet, const CoinEligibilityFilter& filter)
 {
+    CoinSelectionParams coin_selection_params(/* change_output_size= */ 0,
+                                              /* change_spend_size= */ 0, /* effective_feerate= */ CFeeRate(0),
+                                              /* long_term_feerate= */ CFeeRate(0), /* discard_feerate= */ CFeeRate(0),
+                                              /* tx_noinputs_size= */ 0, /* avoid_partial= */ false);
     static std::vector<OutputGroup> static_groups;
-    static_groups = GroupOutputs(testWallet, vCoins, coin_selection_params, filter, /* positive_only */false);
+    static_groups = GroupOutputs(wallet, coins, coin_selection_params, filter, /* positive_only */false);
     return static_groups;
 }
 
 // Branch and bound coin selection tests
 BOOST_AUTO_TEST_CASE(bnb_search_test)
 {
-
-    LOCK(testWallet.cs_wallet);
-    testWallet.SetupLegacyScriptPubKeyMan();
-
     // Setup
     std::vector<CInputCoin> utxo_pool;
     CoinSet selection;
@@ -288,196 +267,210 @@ BOOST_AUTO_TEST_CASE(bnb_search_test)
                                                   /* change_spend_size= */ 0, /* effective_feerate= */ CFeeRate(3000),
                                                   /* long_term_feerate= */ CFeeRate(1000), /* discard_feerate= */ CFeeRate(1000),
                                                   /* tx_noinputs_size= */ 0, /* avoid_partial= */ false);
-    CoinSet setCoinsRet;
-    CAmount nValueRet;
-    empty_wallet();
-    add_coin(1);
-    vCoins.at(0).nInputBytes = 40; // Make sure that it has a negative effective value. The next check should assert if this somehow got through. Otherwise it will fail
-    BOOST_CHECK(!SelectCoinsBnB(GroupCoins(vCoins), 1 * CENT, coin_selection_params_bnb.m_cost_of_change, setCoinsRet, nValueRet));
-
-    // Test fees subtracted from output:
-    empty_wallet();
-    add_coin(1 * CENT);
-    vCoins.at(0).nInputBytes = 40;
-    coin_selection_params_bnb.m_subtract_fee_outputs = true;
-    BOOST_CHECK(SelectCoinsBnB(GroupCoins(vCoins), 1 * CENT, coin_selection_params_bnb.m_cost_of_change, setCoinsRet, nValueRet));
-    BOOST_CHECK_EQUAL(nValueRet, 1 * CENT);
-
-    // Make sure that can use BnB when there are preset inputs
-    empty_wallet();
     {
         std::unique_ptr<CWallet> wallet = std::make_unique<CWallet>(m_node.chain.get(), "", CreateMockWalletDatabase());
         wallet->LoadWallet();
         wallet->SetupLegacyScriptPubKeyMan();
         LOCK(wallet->cs_wallet);
-        add_coin(*wallet, 5 * CENT, 6 * 24, false, 0, true);
-        add_coin(*wallet, 3 * CENT, 6 * 24, false, 0, true);
-        add_coin(*wallet, 2 * CENT, 6 * 24, false, 0, true);
+
+        std::vector<COutput> coins;
+        CoinSet setCoinsRet;
+        CAmount nValueRet;
+
+        add_coin(coins, *wallet, 1);
+        coins.at(0).nInputBytes = 40; // Make sure that it has a negative effective value. The next check should assert if this somehow got through. Otherwise it will fail
+        BOOST_CHECK(!SelectCoinsBnB(GroupCoins(coins), 1 * CENT, coin_selection_params_bnb.m_cost_of_change, setCoinsRet, nValueRet));
+
+        // Test fees subtracted from output:
+        coins.clear();
+        add_coin(coins, *wallet, 1 * CENT);
+        coins.at(0).nInputBytes = 40;
+        coin_selection_params_bnb.m_subtract_fee_outputs = true;
+        BOOST_CHECK(SelectCoinsBnB(GroupCoins(coins), 1 * CENT, coin_selection_params_bnb.m_cost_of_change, setCoinsRet, nValueRet));
+        BOOST_CHECK_EQUAL(nValueRet, 1 * CENT);
+    }
+
+    {
+        std::unique_ptr<CWallet> wallet = std::make_unique<CWallet>(m_node.chain.get(), "", CreateMockWalletDatabase());
+        wallet->LoadWallet();
+        wallet->SetupLegacyScriptPubKeyMan();
+        LOCK(wallet->cs_wallet);
+
+        std::vector<COutput> coins;
+        CoinSet setCoinsRet;
+        CAmount nValueRet;
+
+        add_coin(coins, *wallet, 5 * CENT, 6 * 24, false, 0, true);
+        add_coin(coins, *wallet, 3 * CENT, 6 * 24, false, 0, true);
+        add_coin(coins, *wallet, 2 * CENT, 6 * 24, false, 0, true);
         CCoinControl coin_control;
         coin_control.fAllowOtherInputs = true;
-        coin_control.Select(COutPoint(vCoins.at(0).tx->GetHash(), vCoins.at(0).i));
+        coin_control.Select(COutPoint(coins.at(0).tx->GetHash(), coins.at(0).i));
         coin_selection_params_bnb.m_effective_feerate = CFeeRate(0);
-        BOOST_CHECK(SelectCoins(*wallet, vCoins, 10 * CENT, setCoinsRet, nValueRet, coin_control, coin_selection_params_bnb));
+        BOOST_CHECK(SelectCoins(*wallet, coins, 10 * CENT, setCoinsRet, nValueRet, coin_control, coin_selection_params_bnb));
     }
 }
 
 BOOST_AUTO_TEST_CASE(knapsack_solver_test)
 {
+    std::unique_ptr<CWallet> wallet = std::make_unique<CWallet>(m_node.chain.get(), "", CreateMockWalletDatabase());
+    wallet->LoadWallet();
+    wallet->SetupLegacyScriptPubKeyMan();
+    LOCK(wallet->cs_wallet);
+
     CoinSet setCoinsRet, setCoinsRet2;
     CAmount nValueRet;
-
-    LOCK(testWallet.cs_wallet);
-    testWallet.SetupLegacyScriptPubKeyMan();
+    std::vector<COutput> coins;
 
     // test multiple times to allow for differences in the shuffle order
     for (int i = 0; i < RUN_TESTS; i++)
     {
-        empty_wallet();
+        coins.clear();
 
         // with an empty wallet we can't even pay one cent
-        BOOST_CHECK(!KnapsackSolver(1 * CENT, KnapsackGroupOutputs(filter_standard), setCoinsRet, nValueRet));
+        BOOST_CHECK(!KnapsackSolver(1 * CENT, KnapsackGroupOutputs(coins, *wallet, filter_standard), setCoinsRet, nValueRet));
 
-        add_coin(1*CENT, 4);        // add a new 1 cent coin
+        add_coin(coins, *wallet, 1*CENT, 4);        // add a new 1 cent coin
 
         // with a new 1 cent coin, we still can't find a mature 1 cent
-        BOOST_CHECK(!KnapsackSolver(1 * CENT, KnapsackGroupOutputs(filter_standard), setCoinsRet, nValueRet));
+        BOOST_CHECK(!KnapsackSolver(1 * CENT, KnapsackGroupOutputs(coins, *wallet, filter_standard), setCoinsRet, nValueRet));
 
         // but we can find a new 1 cent
-        BOOST_CHECK(KnapsackSolver(1 * CENT, KnapsackGroupOutputs(filter_confirmed), setCoinsRet, nValueRet));
+        BOOST_CHECK(KnapsackSolver(1 * CENT, KnapsackGroupOutputs(coins, *wallet, filter_confirmed), setCoinsRet, nValueRet));
         BOOST_CHECK_EQUAL(nValueRet, 1 * CENT);
 
-        add_coin(2*CENT);           // add a mature 2 cent coin
+        add_coin(coins, *wallet, 2*CENT);           // add a mature 2 cent coin
 
         // we can't make 3 cents of mature coins
-        BOOST_CHECK(!KnapsackSolver(3 * CENT, KnapsackGroupOutputs(filter_standard), setCoinsRet, nValueRet));
+        BOOST_CHECK(!KnapsackSolver(3 * CENT, KnapsackGroupOutputs(coins, *wallet, filter_standard), setCoinsRet, nValueRet));
 
         // we can make 3 cents of new coins
-        BOOST_CHECK(KnapsackSolver(3 * CENT, KnapsackGroupOutputs(filter_confirmed), setCoinsRet, nValueRet));
+        BOOST_CHECK(KnapsackSolver(3 * CENT, KnapsackGroupOutputs(coins, *wallet, filter_confirmed), setCoinsRet, nValueRet));
         BOOST_CHECK_EQUAL(nValueRet, 3 * CENT);
 
-        add_coin(5*CENT);           // add a mature 5 cent coin,
-        add_coin(10*CENT, 3, true); // a new 10 cent coin sent from one of our own addresses
-        add_coin(20*CENT);          // and a mature 20 cent coin
+        add_coin(coins, *wallet, 5*CENT);           // add a mature 5 cent coin,
+        add_coin(coins, *wallet, 10*CENT, 3, true); // a new 10 cent coin sent from one of our own addresses
+        add_coin(coins, *wallet, 20*CENT);          // and a mature 20 cent coin
 
         // now we have new: 1+10=11 (of which 10 was self-sent), and mature: 2+5+20=27.  total = 38
 
         // we can't make 38 cents only if we disallow new coins:
-        BOOST_CHECK(!KnapsackSolver(38 * CENT, KnapsackGroupOutputs(filter_standard), setCoinsRet, nValueRet));
+        BOOST_CHECK(!KnapsackSolver(38 * CENT, KnapsackGroupOutputs(coins, *wallet, filter_standard), setCoinsRet, nValueRet));
         // we can't even make 37 cents if we don't allow new coins even if they're from us
-        BOOST_CHECK(!KnapsackSolver(38 * CENT, KnapsackGroupOutputs(filter_standard_extra), setCoinsRet, nValueRet));
+        BOOST_CHECK(!KnapsackSolver(38 * CENT, KnapsackGroupOutputs(coins, *wallet, filter_standard_extra), setCoinsRet, nValueRet));
         // but we can make 37 cents if we accept new coins from ourself
-        BOOST_CHECK(KnapsackSolver(37 * CENT, KnapsackGroupOutputs(filter_standard), setCoinsRet, nValueRet));
+        BOOST_CHECK(KnapsackSolver(37 * CENT, KnapsackGroupOutputs(coins, *wallet, filter_standard), setCoinsRet, nValueRet));
         BOOST_CHECK_EQUAL(nValueRet, 37 * CENT);
         // and we can make 38 cents if we accept all new coins
-        BOOST_CHECK(KnapsackSolver(38 * CENT, KnapsackGroupOutputs(filter_confirmed), setCoinsRet, nValueRet));
+        BOOST_CHECK(KnapsackSolver(38 * CENT, KnapsackGroupOutputs(coins, *wallet, filter_confirmed), setCoinsRet, nValueRet));
         BOOST_CHECK_EQUAL(nValueRet, 38 * CENT);
 
         // try making 34 cents from 1,2,5,10,20 - we can't do it exactly
-        BOOST_CHECK(KnapsackSolver(34 * CENT, KnapsackGroupOutputs(filter_confirmed), setCoinsRet, nValueRet));
+        BOOST_CHECK(KnapsackSolver(34 * CENT, KnapsackGroupOutputs(coins, *wallet, filter_confirmed), setCoinsRet, nValueRet));
         BOOST_CHECK_EQUAL(nValueRet, 35 * CENT);       // but 35 cents is closest
         BOOST_CHECK_EQUAL(setCoinsRet.size(), 3U);     // the best should be 20+10+5.  it's incredibly unlikely the 1 or 2 got included (but possible)
 
         // when we try making 7 cents, the smaller coins (1,2,5) are enough.  We should see just 2+5
-        BOOST_CHECK(KnapsackSolver(7 * CENT, KnapsackGroupOutputs(filter_confirmed), setCoinsRet, nValueRet));
+        BOOST_CHECK(KnapsackSolver(7 * CENT, KnapsackGroupOutputs(coins, *wallet, filter_confirmed), setCoinsRet, nValueRet));
         BOOST_CHECK_EQUAL(nValueRet, 7 * CENT);
         BOOST_CHECK_EQUAL(setCoinsRet.size(), 2U);
 
         // when we try making 8 cents, the smaller coins (1,2,5) are exactly enough.
-        BOOST_CHECK(KnapsackSolver(8 * CENT, KnapsackGroupOutputs(filter_confirmed), setCoinsRet, nValueRet));
+        BOOST_CHECK(KnapsackSolver(8 * CENT, KnapsackGroupOutputs(coins, *wallet, filter_confirmed), setCoinsRet, nValueRet));
         BOOST_CHECK(nValueRet == 8 * CENT);
         BOOST_CHECK_EQUAL(setCoinsRet.size(), 3U);
 
         // when we try making 9 cents, no subset of smaller coins is enough, and we get the next bigger coin (10)
-        BOOST_CHECK(KnapsackSolver(9 * CENT, KnapsackGroupOutputs(filter_confirmed), setCoinsRet, nValueRet));
+        BOOST_CHECK(KnapsackSolver(9 * CENT, KnapsackGroupOutputs(coins, *wallet, filter_confirmed), setCoinsRet, nValueRet));
         BOOST_CHECK_EQUAL(nValueRet, 10 * CENT);
         BOOST_CHECK_EQUAL(setCoinsRet.size(), 1U);
 
         // now clear out the wallet and start again to test choosing between subsets of smaller coins and the next biggest coin
-        empty_wallet();
+        coins.clear();
 
-        add_coin( 6*CENT);
-        add_coin( 7*CENT);
-        add_coin( 8*CENT);
-        add_coin(20*CENT);
-        add_coin(30*CENT); // now we have 6+7+8+20+30 = 71 cents total
+        add_coin(coins, *wallet,  6*CENT);
+        add_coin(coins, *wallet,  7*CENT);
+        add_coin(coins, *wallet,  8*CENT);
+        add_coin(coins, *wallet, 20*CENT);
+        add_coin(coins, *wallet, 30*CENT); // now we have 6+7+8+20+30 = 71 cents total
 
         // check that we have 71 and not 72
-        BOOST_CHECK(KnapsackSolver(71 * CENT, KnapsackGroupOutputs(filter_confirmed), setCoinsRet, nValueRet));
-        BOOST_CHECK(!KnapsackSolver(72 * CENT, KnapsackGroupOutputs(filter_confirmed), setCoinsRet, nValueRet));
+        BOOST_CHECK(KnapsackSolver(71 * CENT, KnapsackGroupOutputs(coins, *wallet, filter_confirmed), setCoinsRet, nValueRet));
+        BOOST_CHECK(!KnapsackSolver(72 * CENT, KnapsackGroupOutputs(coins, *wallet, filter_confirmed), setCoinsRet, nValueRet));
 
         // 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
-        BOOST_CHECK(KnapsackSolver(16 * CENT, KnapsackGroupOutputs(filter_confirmed), setCoinsRet, nValueRet));
+        BOOST_CHECK(KnapsackSolver(16 * CENT, KnapsackGroupOutputs(coins, *wallet, filter_confirmed), setCoinsRet, nValueRet));
         BOOST_CHECK_EQUAL(nValueRet, 20 * CENT); // we should get 20 in one coin
         BOOST_CHECK_EQUAL(setCoinsRet.size(), 1U);
 
-        add_coin( 5*CENT); // now we have 5+6+7+8+20+30 = 75 cents total
+        add_coin(coins, *wallet,  5*CENT); // now we have 5+6+7+8+20+30 = 75 cents total
 
         // 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
-        BOOST_CHECK(KnapsackSolver(16 * CENT, KnapsackGroupOutputs(filter_confirmed), setCoinsRet, nValueRet));
+        BOOST_CHECK(KnapsackSolver(16 * CENT, KnapsackGroupOutputs(coins, *wallet, filter_confirmed), setCoinsRet, nValueRet));
         BOOST_CHECK_EQUAL(nValueRet, 18 * CENT); // we should get 18 in 3 coins
         BOOST_CHECK_EQUAL(setCoinsRet.size(), 3U);
 
-        add_coin( 18*CENT); // now we have 5+6+7+8+18+20+30
+        add_coin(coins, *wallet,  18*CENT); // now we have 5+6+7+8+18+20+30
 
         // 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
-        BOOST_CHECK(KnapsackSolver(16 * CENT, KnapsackGroupOutputs(filter_confirmed), setCoinsRet, nValueRet));
+        BOOST_CHECK(KnapsackSolver(16 * CENT, KnapsackGroupOutputs(coins, *wallet, filter_confirmed), setCoinsRet, nValueRet));
         BOOST_CHECK_EQUAL(nValueRet, 18 * CENT);  // we should get 18 in 1 coin
         BOOST_CHECK_EQUAL(setCoinsRet.size(), 1U); // because in the event of a tie, the biggest coin wins
 
         // now try making 11 cents.  we should get 5+6
-        BOOST_CHECK(KnapsackSolver(11 * CENT, KnapsackGroupOutputs(filter_confirmed), setCoinsRet, nValueRet));
+        BOOST_CHECK(KnapsackSolver(11 * CENT, KnapsackGroupOutputs(coins, *wallet, filter_confirmed), setCoinsRet, nValueRet));
         BOOST_CHECK_EQUAL(nValueRet, 11 * CENT);
         BOOST_CHECK_EQUAL(setCoinsRet.size(), 2U);
 
         // check that the smallest bigger coin is used
-        add_coin( 1*COIN);
-        add_coin( 2*COIN);
-        add_coin( 3*COIN);
-        add_coin( 4*COIN); // now we have 5+6+7+8+18+20+30+100+200+300+400 = 1094 cents
-        BOOST_CHECK(KnapsackSolver(95 * CENT, KnapsackGroupOutputs(filter_confirmed), setCoinsRet, nValueRet));
+        add_coin(coins, *wallet,  1*COIN);
+        add_coin(coins, *wallet,  2*COIN);
+        add_coin(coins, *wallet,  3*COIN);
+        add_coin(coins, *wallet,  4*COIN); // now we have 5+6+7+8+18+20+30+100+200+300+400 = 1094 cents
+        BOOST_CHECK(KnapsackSolver(95 * CENT, KnapsackGroupOutputs(coins, *wallet, filter_confirmed), setCoinsRet, nValueRet));
         BOOST_CHECK_EQUAL(nValueRet, 1 * COIN);  // we should get 1 BTC in 1 coin
         BOOST_CHECK_EQUAL(setCoinsRet.size(), 1U);
 
-        BOOST_CHECK(KnapsackSolver(195 * CENT, KnapsackGroupOutputs(filter_confirmed), setCoinsRet, nValueRet));
+        BOOST_CHECK(KnapsackSolver(195 * CENT, KnapsackGroupOutputs(coins, *wallet, filter_confirmed), setCoinsRet, nValueRet));
         BOOST_CHECK_EQUAL(nValueRet, 2 * COIN);  // we should get 2 BTC in 1 coin
         BOOST_CHECK_EQUAL(setCoinsRet.size(), 1U);
 
         // empty the wallet and start again, now with fractions of a cent, to test small change avoidance
 
-        empty_wallet();
-        add_coin(MIN_CHANGE * 1 / 10);
-        add_coin(MIN_CHANGE * 2 / 10);
-        add_coin(MIN_CHANGE * 3 / 10);
-        add_coin(MIN_CHANGE * 4 / 10);
-        add_coin(MIN_CHANGE * 5 / 10);
+        coins.clear();
+        add_coin(coins, *wallet, MIN_CHANGE * 1 / 10);
+        add_coin(coins, *wallet, MIN_CHANGE * 2 / 10);
+        add_coin(coins, *wallet, MIN_CHANGE * 3 / 10);
+        add_coin(coins, *wallet, MIN_CHANGE * 4 / 10);
+        add_coin(coins, *wallet, MIN_CHANGE * 5 / 10);
 
         // try making 1 * MIN_CHANGE from the 1.5 * MIN_CHANGE
         // we'll get change smaller than MIN_CHANGE whatever happens, so can expect MIN_CHANGE exactly
-        BOOST_CHECK(KnapsackSolver(MIN_CHANGE, KnapsackGroupOutputs(filter_confirmed), setCoinsRet, nValueRet));
+        BOOST_CHECK(KnapsackSolver(MIN_CHANGE, KnapsackGroupOutputs(coins, *wallet, filter_confirmed), setCoinsRet, nValueRet));
         BOOST_CHECK_EQUAL(nValueRet, MIN_CHANGE);
 
         // but if we add a bigger coin, small change is avoided
-        add_coin(1111*MIN_CHANGE);
+        add_coin(coins, *wallet, 1111*MIN_CHANGE);
 
         // try making 1 from 0.1 + 0.2 + 0.3 + 0.4 + 0.5 + 1111 = 1112.5
-        BOOST_CHECK(KnapsackSolver(1 * MIN_CHANGE, KnapsackGroupOutputs(filter_confirmed), setCoinsRet, nValueRet));
+        BOOST_CHECK(KnapsackSolver(1 * MIN_CHANGE, KnapsackGroupOutputs(coins, *wallet, filter_confirmed), setCoinsRet, nValueRet));
         BOOST_CHECK_EQUAL(nValueRet, 1 * MIN_CHANGE); // we should get the exact amount
 
         // if we add more small coins:
-        add_coin(MIN_CHANGE * 6 / 10);
-        add_coin(MIN_CHANGE * 7 / 10);
+        add_coin(coins, *wallet, MIN_CHANGE * 6 / 10);
+        add_coin(coins, *wallet, MIN_CHANGE * 7 / 10);
 
         // and try again to make 1.0 * MIN_CHANGE
-        BOOST_CHECK(KnapsackSolver(1 * MIN_CHANGE, KnapsackGroupOutputs(filter_confirmed), setCoinsRet, nValueRet));
+        BOOST_CHECK(KnapsackSolver(1 * MIN_CHANGE, KnapsackGroupOutputs(coins, *wallet, filter_confirmed), setCoinsRet, nValueRet));
         BOOST_CHECK_EQUAL(nValueRet, 1 * MIN_CHANGE); // we should get the exact amount
 
         // run the 'mtgox' test (see https://blockexplorer.com/tx/29a3efd3ef04f9153d47a990bd7b048a4b2d213daaa5fb8ed670fb85f13bdbcf)
         // they tried to consolidate 10 50k coins into one 500k coin, and ended up with 50k in change
-        empty_wallet();
+        coins.clear();
         for (int j = 0; j < 20; j++)
-            add_coin(50000 * COIN);
+            add_coin(coins, *wallet, 50000 * COIN);
 
-        BOOST_CHECK(KnapsackSolver(500000 * COIN, KnapsackGroupOutputs(filter_confirmed), setCoinsRet, nValueRet));
+        BOOST_CHECK(KnapsackSolver(500000 * COIN, KnapsackGroupOutputs(coins, *wallet, filter_confirmed), setCoinsRet, nValueRet));
         BOOST_CHECK_EQUAL(nValueRet, 500000 * COIN); // we should get the exact amount
         BOOST_CHECK_EQUAL(setCoinsRet.size(), 10U); // in ten coins
 
@@ -485,79 +478,79 @@ BOOST_AUTO_TEST_CASE(knapsack_solver_test)
         // we need to try finding an exact subset anyway
 
         // sometimes it will fail, and so we use the next biggest coin:
-        empty_wallet();
-        add_coin(MIN_CHANGE * 5 / 10);
-        add_coin(MIN_CHANGE * 6 / 10);
-        add_coin(MIN_CHANGE * 7 / 10);
-        add_coin(1111 * MIN_CHANGE);
-        BOOST_CHECK(KnapsackSolver(1 * MIN_CHANGE, KnapsackGroupOutputs(filter_confirmed), setCoinsRet, nValueRet));
+        coins.clear();
+        add_coin(coins, *wallet, MIN_CHANGE * 5 / 10);
+        add_coin(coins, *wallet, MIN_CHANGE * 6 / 10);
+        add_coin(coins, *wallet, MIN_CHANGE * 7 / 10);
+        add_coin(coins, *wallet, 1111 * MIN_CHANGE);
+        BOOST_CHECK(KnapsackSolver(1 * MIN_CHANGE, KnapsackGroupOutputs(coins, *wallet, filter_confirmed), setCoinsRet, nValueRet));
         BOOST_CHECK_EQUAL(nValueRet, 1111 * MIN_CHANGE); // we get the bigger coin
         BOOST_CHECK_EQUAL(setCoinsRet.size(), 1U);
 
         // but sometimes it's possible, and we use an exact subset (0.4 + 0.6 = 1.0)
-        empty_wallet();
-        add_coin(MIN_CHANGE * 4 / 10);
-        add_coin(MIN_CHANGE * 6 / 10);
-        add_coin(MIN_CHANGE * 8 / 10);
-        add_coin(1111 * MIN_CHANGE);
-        BOOST_CHECK(KnapsackSolver(MIN_CHANGE, KnapsackGroupOutputs(filter_confirmed), setCoinsRet, nValueRet));
+        coins.clear();
+        add_coin(coins, *wallet, MIN_CHANGE * 4 / 10);
+        add_coin(coins, *wallet, MIN_CHANGE * 6 / 10);
+        add_coin(coins, *wallet, MIN_CHANGE * 8 / 10);
+        add_coin(coins, *wallet, 1111 * MIN_CHANGE);
+        BOOST_CHECK(KnapsackSolver(MIN_CHANGE, KnapsackGroupOutputs(coins, *wallet, filter_confirmed), setCoinsRet, nValueRet));
         BOOST_CHECK_EQUAL(nValueRet, MIN_CHANGE);   // we should get the exact amount
         BOOST_CHECK_EQUAL(setCoinsRet.size(), 2U); // in two coins 0.4+0.6
 
         // test avoiding small change
-        empty_wallet();
-        add_coin(MIN_CHANGE * 5 / 100);
-        add_coin(MIN_CHANGE * 1);
-        add_coin(MIN_CHANGE * 100);
+        coins.clear();
+        add_coin(coins, *wallet, MIN_CHANGE * 5 / 100);
+        add_coin(coins, *wallet, MIN_CHANGE * 1);
+        add_coin(coins, *wallet, MIN_CHANGE * 100);
 
         // trying to make 100.01 from these three coins
-        BOOST_CHECK(KnapsackSolver(MIN_CHANGE * 10001 / 100, KnapsackGroupOutputs(filter_confirmed), setCoinsRet, nValueRet));
+        BOOST_CHECK(KnapsackSolver(MIN_CHANGE * 10001 / 100, KnapsackGroupOutputs(coins, *wallet, filter_confirmed), setCoinsRet, nValueRet));
         BOOST_CHECK_EQUAL(nValueRet, MIN_CHANGE * 10105 / 100); // we should get all coins
         BOOST_CHECK_EQUAL(setCoinsRet.size(), 3U);
 
         // but if we try to make 99.9, we should take the bigger of the two small coins to avoid small change
-        BOOST_CHECK(KnapsackSolver(MIN_CHANGE * 9990 / 100, KnapsackGroupOutputs(filter_confirmed), setCoinsRet, nValueRet));
+        BOOST_CHECK(KnapsackSolver(MIN_CHANGE * 9990 / 100, KnapsackGroupOutputs(coins, *wallet, filter_confirmed), setCoinsRet, nValueRet));
         BOOST_CHECK_EQUAL(nValueRet, 101 * MIN_CHANGE);
         BOOST_CHECK_EQUAL(setCoinsRet.size(), 2U);
-      }
-
-      // test with many inputs
-      for (CAmount amt=1500; amt < COIN; amt*=10) {
-           empty_wallet();
-           // Create 676 inputs (=  (old MAX_STANDARD_TX_SIZE == 100000)  / 148 bytes per input)
-           for (uint16_t j = 0; j < 676; j++)
-               add_coin(amt);
-
-           // We only create the wallet once to save time, but we still run the coin selection RUN_TESTS times.
-           for (int i = 0; i < RUN_TESTS; i++) {
-             BOOST_CHECK(KnapsackSolver(2000, KnapsackGroupOutputs(filter_confirmed), setCoinsRet, nValueRet));
-
-             if (amt - 2000 < MIN_CHANGE) {
-                 // needs more than one input:
-                 uint16_t returnSize = std::ceil((2000.0 + MIN_CHANGE)/amt);
-                 CAmount returnValue = amt * returnSize;
-                 BOOST_CHECK_EQUAL(nValueRet, returnValue);
-                 BOOST_CHECK_EQUAL(setCoinsRet.size(), returnSize);
-             } else {
-                 // one input is sufficient:
-                 BOOST_CHECK_EQUAL(nValueRet, amt);
-                 BOOST_CHECK_EQUAL(setCoinsRet.size(), 1U);
-             }
-           }
-      }
-
-      // test randomness
-      {
-          empty_wallet();
-          for (int i2 = 0; i2 < 100; i2++)
-              add_coin(COIN);
-
-          // Again, we only create the wallet once to save time, but we still run the coin selection RUN_TESTS times.
-          for (int i = 0; i < RUN_TESTS; i++) {
+    }
+
+    // test with many inputs
+    for (CAmount amt=1500; amt < COIN; amt*=10) {
+        coins.clear();
+        // Create 676 inputs (=  (old MAX_STANDARD_TX_SIZE == 100000)  / 148 bytes per input)
+        for (uint16_t j = 0; j < 676; j++)
+            add_coin(coins, *wallet, amt);
+
+        // We only create the wallet once to save time, but we still run the coin selection RUN_TESTS times.
+        for (int i = 0; i < RUN_TESTS; i++) {
+            BOOST_CHECK(KnapsackSolver(2000, KnapsackGroupOutputs(coins, *wallet, filter_confirmed), setCoinsRet, nValueRet));
+
+            if (amt - 2000 < MIN_CHANGE) {
+                // needs more than one input:
+                uint16_t returnSize = std::ceil((2000.0 + MIN_CHANGE)/amt);
+                CAmount returnValue = amt * returnSize;
+                BOOST_CHECK_EQUAL(nValueRet, returnValue);
+                BOOST_CHECK_EQUAL(setCoinsRet.size(), returnSize);
+            } else {
+                // one input is sufficient:
+                BOOST_CHECK_EQUAL(nValueRet, amt);
+                BOOST_CHECK_EQUAL(setCoinsRet.size(), 1U);
+            }
+        }
+    }
+
+    // test randomness
+    {
+        coins.clear();
+        for (int i2 = 0; i2 < 100; i2++)
+            add_coin(coins, *wallet, COIN);
+
+        // Again, we only create the wallet once to save time, but we still run the coin selection RUN_TESTS times.
+        for (int i = 0; i < RUN_TESTS; i++) {
             // picking 50 from 100 coins doesn't depend on the shuffle,
             // but does depend on randomness in the stochastic approximation code
-            BOOST_CHECK(KnapsackSolver(50 * COIN, GroupCoins(vCoins), setCoinsRet, nValueRet));
-            BOOST_CHECK(KnapsackSolver(50 * COIN, GroupCoins(vCoins), setCoinsRet2, nValueRet));
+            BOOST_CHECK(KnapsackSolver(50 * COIN, GroupCoins(coins), setCoinsRet, nValueRet));
+            BOOST_CHECK(KnapsackSolver(50 * COIN, GroupCoins(coins), setCoinsRet2, nValueRet));
             BOOST_CHECK(!equal_sets(setCoinsRet, setCoinsRet2));
 
             int fails = 0;
@@ -567,66 +560,65 @@ BOOST_AUTO_TEST_CASE(knapsack_solver_test)
                 // When choosing 1 from 100 identical coins, 1% of the time, this test will choose the same coin twice
                 // which will cause it to fail.
                 // To avoid that issue, run the test RANDOM_REPEATS times and only complain if all of them fail
-                BOOST_CHECK(KnapsackSolver(COIN, GroupCoins(vCoins), setCoinsRet, nValueRet));
-                BOOST_CHECK(KnapsackSolver(COIN, GroupCoins(vCoins), setCoinsRet2, nValueRet));
+                BOOST_CHECK(KnapsackSolver(COIN, GroupCoins(coins), setCoinsRet, nValueRet));
+                BOOST_CHECK(KnapsackSolver(COIN, GroupCoins(coins), setCoinsRet2, nValueRet));
                 if (equal_sets(setCoinsRet, setCoinsRet2))
                     fails++;
             }
             BOOST_CHECK_NE(fails, RANDOM_REPEATS);
-          }
-
-          // add 75 cents in small change.  not enough to make 90 cents,
-          // then try making 90 cents.  there are multiple competing "smallest bigger" coins,
-          // one of which should be picked at random
-          add_coin(5 * CENT);
-          add_coin(10 * CENT);
-          add_coin(15 * CENT);
-          add_coin(20 * CENT);
-          add_coin(25 * CENT);
-
-          for (int i = 0; i < RUN_TESTS; i++) {
+        }
+
+        // add 75 cents in small change.  not enough to make 90 cents,
+        // then try making 90 cents.  there are multiple competing "smallest bigger" coins,
+        // one of which should be picked at random
+        add_coin(coins, *wallet, 5 * CENT);
+        add_coin(coins, *wallet, 10 * CENT);
+        add_coin(coins, *wallet, 15 * CENT);
+        add_coin(coins, *wallet, 20 * CENT);
+        add_coin(coins, *wallet, 25 * CENT);
+
+        for (int i = 0; i < RUN_TESTS; i++) {
             int fails = 0;
             for (int j = 0; j < RANDOM_REPEATS; j++)
             {
-                BOOST_CHECK(KnapsackSolver(90*CENT, GroupCoins(vCoins), setCoinsRet, nValueRet));
-                BOOST_CHECK(KnapsackSolver(90*CENT, GroupCoins(vCoins), setCoinsRet2, nValueRet));
+                BOOST_CHECK(KnapsackSolver(90*CENT, GroupCoins(coins), setCoinsRet, nValueRet));
+                BOOST_CHECK(KnapsackSolver(90*CENT, GroupCoins(coins), setCoinsRet2, nValueRet));
                 if (equal_sets(setCoinsRet, setCoinsRet2))
                     fails++;
             }
             BOOST_CHECK_NE(fails, RANDOM_REPEATS);
-          }
-      }
-
-    empty_wallet();
+        }
+    }
 }
 
 BOOST_AUTO_TEST_CASE(ApproximateBestSubset)
 {
+    std::unique_ptr<CWallet> wallet = std::make_unique<CWallet>(m_node.chain.get(), "", CreateMockWalletDatabase());
+    wallet->LoadWallet();
+    wallet->SetupLegacyScriptPubKeyMan();
+    LOCK(wallet->cs_wallet);
+
     CoinSet setCoinsRet;
     CAmount nValueRet;
-
-    LOCK(testWallet.cs_wallet);
-    testWallet.SetupLegacyScriptPubKeyMan();
-
-    empty_wallet();
+    std::vector<COutput> coins;
 
     // Test vValue sort order
     for (int i = 0; i < 1000; i++)
-        add_coin(1000 * COIN);
-    add_coin(3 * COIN);
+        add_coin(coins, *wallet, 1000 * COIN);
+    add_coin(coins, *wallet, 3 * COIN);
 
-    BOOST_CHECK(KnapsackSolver(1003 * COIN, KnapsackGroupOutputs(filter_standard), setCoinsRet, nValueRet));
+    BOOST_CHECK(KnapsackSolver(1003 * COIN, KnapsackGroupOutputs(coins, *wallet, filter_standard), setCoinsRet, nValueRet));
     BOOST_CHECK_EQUAL(nValueRet, 1003 * COIN);
     BOOST_CHECK_EQUAL(setCoinsRet.size(), 2U);
-
-    empty_wallet();
 }
 
 // Tests that with the ideal conditions, the coin selector will always be able to find a solution that can pay the target value
 BOOST_AUTO_TEST_CASE(SelectCoins_test)
 {
-    LOCK(testWallet.cs_wallet);
-    testWallet.SetupLegacyScriptPubKeyMan();
+    std::unique_ptr<CWallet> wallet = std::make_unique<CWallet>(m_node.chain.get(), "", CreateMockWalletDatabase());
+    wallet->LoadWallet();
+    wallet->SetupLegacyScriptPubKeyMan();
+    LOCK(wallet->cs_wallet);
 
     // Random generator stuff
     std::default_random_engine generator;
@@ -636,12 +628,15 @@ BOOST_AUTO_TEST_CASE(SelectCoins_test)
     // Run this test 100 times
     for (int i = 0; i < 100; ++i)
     {
-        empty_wallet();
+        std::vector<COutput> coins;
+        CAmount balance{0};
 
         // Make a wallet with 1000 exponentially distributed random inputs
         for (int j = 0; j < 1000; ++j)
         {
-            add_coin((CAmount)(distribution(generator)*10000000));
+            CAmount val = distribution(generator)*10000000;
+            add_coin(coins, *wallet, val);
+            balance += val;
         }
 
         // Generate a random fee rate in the range of 100 - 400
@@ -658,7 +653,7 @@ BOOST_AUTO_TEST_CASE(SelectCoins_test)
         CoinSet out_set;
         CAmount out_value = 0;
         CCoinControl cc;
-        BOOST_CHECK(SelectCoins(testWallet, vCoins, target, out_set, out_value, cc, cs_params));
+        BOOST_CHECK(SelectCoins(*wallet, coins, target, out_set, out_value, cc, cs_params));
         BOOST_CHECK_GE(out_value, target);
     }
 }