Test that the coin selection code is suitably random, and add tests re. sub-cent change.

This commit is contained in:
Chris Moore 2012-04-07 10:55:03 -07:00 committed by Luke Dashjr
parent e333ab56d5
commit 4ce190a015

View File

@ -9,8 +9,14 @@
// enables tests which currently fail, due to code which tries too hard to avoid sub-cent change
// #define STRICT
// some tests fail 1% of the time due to bad luck.
// we repeat those tests this many times and only complain if all iterations of the test fail
#define RANDOM_REPEATS 5
using namespace std;
typedef set<pair<const CWalletTx*,unsigned int> > CoinSet;
BOOST_AUTO_TEST_SUITE(wallet_tests)
static CWallet wallet;
@ -44,9 +50,15 @@ static void empty_wallet(void)
vCoins.clear();
}
static bool equal_sets(CoinSet a, CoinSet b)
{
pair<CoinSet::iterator, CoinSet::iterator> ret = mismatch(a.begin(), a.end(), b.begin());
return ret.first == a.end() && ret.second == b.end();
}
BOOST_AUTO_TEST_CASE(coin_selection_tests)
{
static set<pair<const CWalletTx*,unsigned int> > setCoinsRet;
static CoinSet setCoinsRet, setCoinsRet2;
static int64 nValueRet;
// test multiple times to allow for differences in the shuffle order
@ -250,6 +262,64 @@ BOOST_AUTO_TEST_CASE(coin_selection_tests)
BOOST_CHECK_EQUAL(nValueRet, 1111 * CENT); // but since value of smaller coins < target+cent, we get the bigger coin again
BOOST_CHECK_EQUAL(setCoinsRet.size(), 1);
#endif
// test avoiding sub-cent change
empty_wallet();
add_coin(0.0005 * COIN);
add_coin(0.01 * COIN);
add_coin(1 * COIN);
// trying to make 1.0001 from these three coins
BOOST_CHECK( wallet.SelectCoinsMinConf(1.0001 * COIN, 1, 1, vCoins, setCoinsRet, nValueRet));
BOOST_CHECK_EQUAL(nValueRet, 1.0105 * COIN); // we should get all coins
BOOST_CHECK_EQUAL(setCoinsRet.size(), 3);
// but if we try to make 0.999, we should take the bigger of the two small coins to avoid sub-cent change
BOOST_CHECK( wallet.SelectCoinsMinConf(0.999 * COIN, 1, 1, vCoins, setCoinsRet, nValueRet));
BOOST_CHECK_EQUAL(nValueRet, 1.01 * COIN); // we should get 1 + 0.01
BOOST_CHECK_EQUAL(setCoinsRet.size(), 2);
// test randomness
{
empty_wallet();
for (int i2 = 0; i2 < 100; i2++)
add_coin(COIN);
// picking 50 from 100 coins doesn't depend on the shuffle,
// but does depend on randomness in the stochastic approximation code
BOOST_CHECK(wallet.SelectCoinsMinConf(50 * COIN, 1, 6, vCoins, setCoinsRet , nValueRet));
BOOST_CHECK(wallet.SelectCoinsMinConf(50 * COIN, 1, 6, vCoins, setCoinsRet2, nValueRet));
BOOST_CHECK(!equal_sets(setCoinsRet, setCoinsRet2));
int fails = 0;
for (int i = 0; i < RANDOM_REPEATS; i++)
{
// selecting 1 from 100 identical coins depends on the shuffle; this test will fail 1% of the time
// run the test RANDOM_REPEATS times and only complain if all of them fail
BOOST_CHECK(wallet.SelectCoinsMinConf(COIN, 1, 6, vCoins, setCoinsRet , nValueRet));
BOOST_CHECK(wallet.SelectCoinsMinConf(COIN, 1, 6, vCoins, 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);
fails = 0;
for (int i = 0; i < RANDOM_REPEATS; i++)
{
// selecting 1 from 100 identical coins depends on the shuffle; this test will fail 1% of the time
// run the test RANDOM_REPEATS times and only complain if all of them fail
BOOST_CHECK(wallet.SelectCoinsMinConf(90*CENT, 1, 6, vCoins, setCoinsRet , nValueRet));
BOOST_CHECK(wallet.SelectCoinsMinConf(90*CENT, 1, 6, vCoins, setCoinsRet2, nValueRet));
if (equal_sets(setCoinsRet, setCoinsRet2))
fails++;
}
BOOST_CHECK_NE(fails, RANDOM_REPEATS);
}
}
}