path: root/TestHelper.cpp

/*
    This file is part of cpp-ethereum.

    cpp-ethereum is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    cpp-ethereum is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with cpp-ethereum.  If not, see <http://www.gnu.org/licenses/>.
*/
/** @file TestHelper.cpp
 * @author Marko Simovic <markobarko@gmail.com>
 * @date 2014
 */

#include "TestHelper.h"

#include <thread>
#include <chrono>

#include <boost/filesystem/path.hpp>

#include <libethereum/Client.h>
#include <liblll/Compiler.h>
#include <libevm/VMFactory.h>
#include "Stats.h"

using namespace std;
using namespace dev::eth;

namespace dev
{
namespace eth
{

void mine(Client& c, int numBlocks)
{
    auto startBlock = c.blockChain().details().number;

    c.startMining();
    while(c.blockChain().details().number < startBlock + numBlocks)
        std::this_thread::sleep_for(std::chrono::milliseconds(100));
    c.stopMining();
}

void connectClients(Client& c1, Client& c2)
{
    (void)c1;
    (void)c2;
    // TODO: Move to WebThree. eth::Client no longer handles networking.
#if 0
    short c1Port = 20000;
    short c2Port = 21000;
    c1.startNetwork(c1Port);
    c2.startNetwork(c2Port);
    c2.connect("127.0.0.1", c1Port);
#endif
}
}

namespace test
{

struct ValueTooLarge: virtual Exception {};
struct MissingFields : virtual Exception {};

bigint const c_max256plus1 = bigint(1) << 256;

ImportTest::ImportTest(json_spirit::mObject& _o, bool isFiller):
    m_statePre(OverlayDB(), eth::BaseState::Empty, Address(_o["env"].get_obj()["currentCoinbase"].get_str())),
    m_statePost(OverlayDB(), eth::BaseState::Empty, Address(_o["env"].get_obj()["currentCoinbase"].get_str())),
    m_TestObject(_o)
{
    importEnv(_o["env"].get_obj());
    importState(_o["pre"].get_obj(), m_statePre);
    importTransaction(_o["transaction"].get_obj());

    if (!isFiller)
    {
        importState(_o["post"].get_obj(), m_statePost);
        m_environment.sub.logs = importLog(_o["logs"].get_array());
    }
}

void ImportTest::importEnv(json_spirit::mObject& _o)
{
    assert(_o.count("previousHash") > 0);
    assert(_o.count("currentGasLimit") > 0);
    assert(_o.count("currentDifficulty") > 0);
    assert(_o.count("currentTimestamp") > 0);
    assert(_o.count("currentCoinbase") > 0);
    assert(_o.count("currentNumber") > 0);

    m_environment.currentBlock.parentHash = h256(_o["previousHash"].get_str());
    m_environment.currentBlock.number = toInt(_o["currentNumber"]);
    m_environment.currentBlock.gasLimit = toInt(_o["currentGasLimit"]);
    m_environment.currentBlock.difficulty = toInt(_o["currentDifficulty"]);
    m_environment.currentBlock.timestamp = toInt(_o["currentTimestamp"]);
    m_environment.currentBlock.coinbaseAddress = Address(_o["currentCoinbase"].get_str());

    m_statePre.m_previousBlock = m_environment.previousBlock;
    m_statePre.m_currentBlock = m_environment.currentBlock;
}

// import state from not fully declared json_spirit::mObject, writing to _stateOptionsMap which fields were defined in json

void ImportTest::importState(json_spirit::mObject& _o, State& _state, stateOptionsMap& _stateOptionsMap)
{
    for (auto& i: _o)
    {
        json_spirit::mObject o = i.second.get_obj();

        ImportStateOptions stateOptions;
        u256 balance = 0;
        u256 nonce = 0;

        if (o.count("balance") > 0)
        {
            stateOptions.m_bHasBalance = true;
            if (bigint(o["balance"].get_str()) >= c_max256plus1)
                BOOST_THROW_EXCEPTION(ValueTooLarge() << errinfo_comment("State 'balance' is equal or greater than 2**256") );
            balance = toInt(o["balance"]);
        }

        if (o.count("nonce") > 0)
        {
            stateOptions.m_bHasNonce = true;
            if (bigint(o["nonce"].get_str()) >= c_max256plus1)
                BOOST_THROW_EXCEPTION(ValueTooLarge() << errinfo_comment("State 'nonce' is equal or greater than 2**256") );
            nonce = toInt(o["nonce"]);
        }

        Address address = Address(i.first);

        bytes code;
        if (o.count("code") > 0)
        {
            code = importCode(o);
            stateOptions.m_bHasCode = true;
        }

        if (code.size())
        {
            _state.m_cache[address] = Account(balance, Account::ContractConception);
            _state.m_cache[address].setCode(code);
        }
        else
            _state.m_cache[address] = Account(balance, Account::NormalCreation);

        if (o.count("storage") > 0)
        {
            stateOptions.m_bHasStorage = true;
            for (auto const& j: o["storage"].get_obj())
                _state.setStorage(address, toInt(j.first), toInt(j.second));
        }

        for (int i = 0; i < nonce; ++i)
            _state.noteSending(address);

        _state.ensureCached(address, false, false);
        _stateOptionsMap[address] = stateOptions;
    }
}

void ImportTest::importState(json_spirit::mObject& _o, State& _state)
{
    stateOptionsMap importedMap;
    importState(_o, _state, importedMap);
    for (auto& stateOptionMap : importedMap)
    {
        //check that every parameter was declared in state object
        if (!stateOptionMap.second.isAllSet())
            BOOST_THROW_EXCEPTION(MissingFields() << errinfo_comment("Import State: Missing state fields!"));   
    }
}

void ImportTest::importTransaction(json_spirit::mObject& _o)
{   
    if (_o.count("secretKey") > 0)
    {
        assert(_o.count("nonce") > 0);
        assert(_o.count("gasPrice") > 0);
        assert(_o.count("gasLimit") > 0);
        assert(_o.count("to") > 0);
        assert(_o.count("value") > 0);
        assert(_o.count("data") > 0);

        if (bigint(_o["nonce"].get_str()) >= c_max256plus1)
            BOOST_THROW_EXCEPTION(ValueTooLarge() << errinfo_comment("Transaction 'nonce' is equal or greater than 2**256") );
        if (bigint(_o["gasPrice"].get_str()) >= c_max256plus1)
            BOOST_THROW_EXCEPTION(ValueTooLarge() << errinfo_comment("Transaction 'gasPrice' is equal or greater than 2**256") );
        if (bigint(_o["gasLimit"].get_str()) >= c_max256plus1)
            BOOST_THROW_EXCEPTION(ValueTooLarge() << errinfo_comment("Transaction 'gasLimit' is equal or greater than 2**256") );
        if (bigint(_o["value"].get_str()) >= c_max256plus1)
            BOOST_THROW_EXCEPTION(ValueTooLarge() << errinfo_comment("Transaction 'value' is equal or greater than 2**256") );

        m_transaction = _o["to"].get_str().empty() ?
            Transaction(toInt(_o["value"]), toInt(_o["gasPrice"]), toInt(_o["gasLimit"]), importData(_o), toInt(_o["nonce"]), Secret(_o["secretKey"].get_str())) :
            Transaction(toInt(_o["value"]), toInt(_o["gasPrice"]), toInt(_o["gasLimit"]), Address(_o["to"].get_str()), importData(_o), toInt(_o["nonce"]), Secret(_o["secretKey"].get_str()));
    }
    else
    {
        RLPStream transactionRLPStream = createRLPStreamFromTransactionFields(_o);
        RLP transactionRLP(transactionRLPStream.out());
        m_transaction = Transaction(transactionRLP.data(), CheckTransaction::Everything);
    }
}

void ImportTest::checkExpectedState(State const& _stateExpect, State const& _statePost, stateOptionsMap const _expectedStateOptions, WhenError _throw)
{
    #define CHECK(a,b)                      \
        {                                   \
            if (_throw == WhenError::Throw) \
                BOOST_CHECK_MESSAGE(a,b);   \
            else                            \
                BOOST_WARN_MESSAGE(a,b);    \
        }

    for (auto const& a: _stateExpect.addresses())
    {
        CHECK(_statePost.addressInUse(a.first), "Filling Test: " << a.first << " missing expected address!");
        if (_statePost.addressInUse(a.first))
        {
            ImportStateOptions addressOptions(true);
            if(_expectedStateOptions.size())
            {
                try
                {
                    addressOptions = _expectedStateOptions.at(a.first);
                }
                catch(std::out_of_range)
                {
                    BOOST_ERROR("expectedStateOptions map does not match expectedState in checkExpectedState!");
                    break;
                }
            }

            if (addressOptions.m_bHasBalance)
                CHECK(_stateExpect.balance(a.first) == _statePost.balance(a.first),
                        "Check State: " << a.first <<  ": incorrect balance " << _statePost.balance(a.first) << ", expected " << _stateExpect.balance(a.first));

            if (addressOptions.m_bHasNonce)
                CHECK(_stateExpect.transactionsFrom(a.first) == _statePost.transactionsFrom(a.first),
                        "Check State: " << a.first <<  ": incorrect nonce " << _statePost.transactionsFrom(a.first) << ", expected " << _stateExpect.transactionsFrom(a.first));

            if (addressOptions.m_bHasStorage)
            {
                map<u256, u256> stateStorage = _statePost.storage(a.first);
                for (auto const& s: _stateExpect.storage(a.first))
                    CHECK(stateStorage[s.first] == s.second,
                            "Check State: " << a.first <<  ": incorrect storage [" << s.first << "] = " << toHex(stateStorage[s.first]) << ", expected [" << s.first << "] = " << toHex(s.second));

                //Check for unexpected storage values
                stateStorage = _stateExpect.storage(a.first);
                for (auto const& s: _statePost.storage(a.first))
                    CHECK(stateStorage[s.first] == s.second,
                            "Check State: " << a.first <<  ": incorrect storage [" << s.first << "] = " << toHex(s.second) << ", expected [" << s.first << "] = " << toHex(stateStorage[s.first]));
            }

            if (addressOptions.m_bHasCode)
                CHECK(_stateExpect.code(a.first) == _statePost.code(a.first),
                        "Check State: " << a.first <<  ": incorrect code '" << toHex(_statePost.code(a.first)) << "', expected '" << toHex(_stateExpect.code(a.first)) << "'");
        }
    }
}

void ImportTest::exportTest(bytes const& _output, State const& _statePost)
{
    // export output
    m_TestObject["out"] = "0x" + toHex(_output);

    // export logs
    m_TestObject["logs"] = exportLog(_statePost.pending().size() ? _statePost.log(0) : LogEntries());

    // compare expected state with post state
    if (m_TestObject.count("expect") > 0)
    {
        stateOptionsMap stateMap;
        State expectState(OverlayDB(), eth::BaseState::Empty);
        importState(m_TestObject["expect"].get_obj(), expectState, stateMap);
        checkExpectedState(expectState, _statePost, stateMap, Options::get().checkState ? WhenError::Throw : WhenError::DontThrow);
        m_TestObject.erase(m_TestObject.find("expect"));
    }

    // export post state
    m_TestObject["post"] = fillJsonWithState(_statePost);
    m_TestObject["postStateRoot"] = toHex(_statePost.rootHash().asBytes());

    // export pre state
    m_TestObject["pre"] = fillJsonWithState(m_statePre);
}

json_spirit::mObject fillJsonWithState(State _state)
{
    // export pre state
    json_spirit::mObject oState;

    for (auto const& a: _state.addresses())
    {
        json_spirit::mObject o;
        o["balance"] = toString(_state.balance(a.first));
        o["nonce"] = toString(_state.transactionsFrom(a.first));
        {
            json_spirit::mObject store;
            for (auto const& s: _state.storage(a.first))
                store["0x"+toHex(toCompactBigEndian(s.first))] = "0x"+toHex(toCompactBigEndian(s.second));
            o["storage"] = store;
        }
        o["code"] = "0x" + toHex(_state.code(a.first));

        oState[toString(a.first)] = o;
    }
    return oState;
}

u256 toInt(json_spirit::mValue const& _v)
{
    switch (_v.type())
    {
    case json_spirit::str_type: return u256(_v.get_str());
    case json_spirit::int_type: return (u256)_v.get_uint64();
    case json_spirit::bool_type: return (u256)(uint64_t)_v.get_bool();
    case json_spirit::real_type: return (u256)(uint64_t)_v.get_real();
    default: cwarn << "Bad type for scalar: " << _v.type();
    }
    return 0;
}

byte toByte(json_spirit::mValue const& _v)
{
    switch (_v.type())
    {
    case json_spirit::str_type: return (byte)stoi(_v.get_str());
    case json_spirit::int_type: return (byte)_v.get_uint64();
    case json_spirit::bool_type: return (byte)_v.get_bool();
    case json_spirit::real_type: return (byte)_v.get_real();
    default: cwarn << "Bad type for scalar: " << _v.type();
    }
    return 0;
}

bytes importByteArray(std::string const& _str)
{
    return fromHex(_str.substr(0, 2) == "0x" ? _str.substr(2) : _str, WhenError::Throw);
}

bytes importData(json_spirit::mObject& _o)
{
    bytes data;
    if (_o["data"].type() == json_spirit::str_type)
        data = importByteArray(_o["data"].get_str());
    else
        for (auto const& j: _o["data"].get_array())
            data.push_back(toByte(j));
    return data;
}

bytes importCode(json_spirit::mObject& _o)
{
    bytes code;
    if (_o["code"].type() == json_spirit::str_type)
        if (_o["code"].get_str().find_first_of("0x") != 0)
            code = compileLLL(_o["code"].get_str(), false);
        else
            code = fromHex(_o["code"].get_str().substr(2));
    else if (_o["code"].type() == json_spirit::array_type)
    {
        code.clear();
        for (auto const& j: _o["code"].get_array())
            code.push_back(toByte(j));
    }
    return code;
}

LogEntries importLog(json_spirit::mArray& _a)
{
    LogEntries logEntries;
    for (auto const& l: _a)
    {
        json_spirit::mObject o = l.get_obj();
        // cant use BOOST_REQUIRE, because this function is used outside boost test (createRandomTest)
        assert(o.count("address") > 0);
        assert(o.count("topics") > 0);
        assert(o.count("data") > 0);
        assert(o.count("bloom") > 0);
        LogEntry log;
        log.address = Address(o["address"].get_str());
        for (auto const& t: o["topics"].get_array())
            log.topics.push_back(h256(t.get_str()));
        log.data = importData(o);
        logEntries.push_back(log);
    }
    return logEntries;
}

json_spirit::mArray exportLog(eth::LogEntries _logs)
{
    json_spirit::mArray ret;
    if (_logs.size() == 0) return ret;
    for (LogEntry const& l: _logs)
    {
        json_spirit::mObject o;
        o["address"] = toString(l.address);
        json_spirit::mArray topics;
        for (auto const& t: l.topics)
            topics.push_back(toString(t));
        o["topics"] = topics;
        o["data"] = "0x" + toHex(l.data);
        o["bloom"] = toString(l.bloom());
        ret.push_back(o);
    }
    return ret;
}

void checkOutput(bytes const& _output, json_spirit::mObject& _o)
{
    int j = 0;
    if (_o["out"].type() == json_spirit::array_type)
        for (auto const& d: _o["out"].get_array())
        {
            BOOST_CHECK_MESSAGE(_output[j] == toInt(d), "Output byte [" << j << "] different!");
            ++j;
        }
    else if (_o["out"].get_str().find("0x") == 0)
        BOOST_CHECK(_output == fromHex(_o["out"].get_str().substr(2)));
    else
        BOOST_CHECK(_output == fromHex(_o["out"].get_str()));
}

void checkStorage(map<u256, u256> _expectedStore, map<u256, u256> _resultStore, Address _expectedAddr)
{
    for (auto&& expectedStorePair : _expectedStore)
    {
        auto& expectedStoreKey = expectedStorePair.first;
        auto resultStoreIt = _resultStore.find(expectedStoreKey);
        if (resultStoreIt == _resultStore.end())
            BOOST_ERROR(_expectedAddr << ": missing store key " << expectedStoreKey);
        else
        {
            auto& expectedStoreValue = expectedStorePair.second;
            auto& resultStoreValue = resultStoreIt->second;
            BOOST_CHECK_MESSAGE(expectedStoreValue == resultStoreValue, _expectedAddr << ": store[" << expectedStoreKey << "] = " << resultStoreValue << ", expected " << expectedStoreValue);
        }
    }
    BOOST_CHECK_EQUAL(_resultStore.size(), _expectedStore.size());
    for (auto&& resultStorePair: _resultStore)
    {
        if (!_expectedStore.count(resultStorePair.first))
            BOOST_ERROR(_expectedAddr << ": unexpected store key " << resultStorePair.first);
    }
}

void checkLog(LogEntries _resultLogs, LogEntries _expectedLogs)
{
    BOOST_REQUIRE_EQUAL(_resultLogs.size(), _expectedLogs.size());

    for (size_t i = 0; i < _resultLogs.size(); ++i)
    {
        BOOST_CHECK_EQUAL(_resultLogs[i].address, _expectedLogs[i].address);
        BOOST_CHECK_EQUAL(_resultLogs[i].topics, _expectedLogs[i].topics);
        BOOST_CHECK(_resultLogs[i].data == _expectedLogs[i].data);
    }
}

void checkCallCreates(eth::Transactions _resultCallCreates, eth::Transactions _expectedCallCreates)
{
    BOOST_REQUIRE_EQUAL(_resultCallCreates.size(), _expectedCallCreates.size());

    for (size_t i = 0; i < _resultCallCreates.size(); ++i)
    {
        BOOST_CHECK(_resultCallCreates[i].data() == _expectedCallCreates[i].data());
        BOOST_CHECK(_resultCallCreates[i].receiveAddress() == _expectedCallCreates[i].receiveAddress());
        BOOST_CHECK(_resultCallCreates[i].gas() == _expectedCallCreates[i].gas());
        BOOST_CHECK(_resultCallCreates[i].value() == _expectedCallCreates[i].value());
    }
}

void userDefinedTest(string testTypeFlag, std::function<void(json_spirit::mValue&, bool)> doTests)
{
    for (int i = 1; i < boost::unit_test::framework::master_test_suite().argc; ++i)
    {
        string arg = boost::unit_test::framework::master_test_suite().argv[i];
        if (arg == testTypeFlag)
        {
            if (boost::unit_test::framework::master_test_suite().argc <= i + 2)
            {
                cnote << "Missing filename\nUsage: testeth " << testTypeFlag << " <filename> <testname>\n";
                return;
            }
            string filename = boost::unit_test::framework::master_test_suite().argv[i + 1];
            string testname = boost::unit_test::framework::master_test_suite().argv[i + 2];
            int currentVerbosity = g_logVerbosity;
            g_logVerbosity = 12;
            try
            {
                cnote << "Testing user defined test: " << filename;
                json_spirit::mValue v;
                string s = asString(contents(filename));
                BOOST_REQUIRE_MESSAGE(s.length() > 0, "Contents of " + filename + " is empty. ");
                json_spirit::read_string(s, v);
                json_spirit::mObject oSingleTest;

                json_spirit::mObject::const_iterator pos = v.get_obj().find(testname);
                if (pos == v.get_obj().end())
                {
                    cnote << "Could not find test: " << testname << " in " << filename << "\n";
                    return;
                }
                else
                    oSingleTest[pos->first] = pos->second;

                json_spirit::mValue v_singleTest(oSingleTest);
                doTests(v_singleTest, false);
            }
            catch (Exception const& _e)
            {
                BOOST_ERROR("Failed Test with Exception: " << diagnostic_information(_e));
                g_logVerbosity = currentVerbosity;
            }
            catch (std::exception const& _e)
            {
                BOOST_ERROR("Failed Test with Exception: " << _e.what());
                g_logVerbosity = currentVerbosity;
            }
            g_logVerbosity = currentVerbosity;
        }
    }
}

void executeTests(const string& _name, const string& _testPathAppendix, std::function<void(json_spirit::mValue&, bool)> doTests)
{
    string testPath = getTestPath();
    testPath += _testPathAppendix;

    if (Options::get().stats)
        Listener::registerListener(Stats::get());

    if (Options::get().fillTests)
    {
        try
        {
            cnote << "Populating tests...";
            json_spirit::mValue v;
            boost::filesystem::path p(__FILE__);
            boost::filesystem::path dir = p.parent_path();
            string s = asString(dev::contents(dir.string() + "/" + _name + "Filler.json"));
            BOOST_REQUIRE_MESSAGE(s.length() > 0, "Contents of " + dir.string() + "/" + _name + "Filler.json is empty.");
            json_spirit::read_string(s, v);
            doTests(v, true);
            writeFile(testPath + "/" + _name + ".json", asBytes(json_spirit::write_string(v, true)));
        }
        catch (Exception const& _e)
        {
            BOOST_ERROR("Failed filling test with Exception: " << diagnostic_information(_e));
        }
        catch (std::exception const& _e)
        {
            BOOST_ERROR("Failed filling test with Exception: " << _e.what());
        }
    }

    try
    {
        std::cout << "TEST " << _name << ":\n";
        json_spirit::mValue v;
        string s = asString(dev::contents(testPath + "/" + _name + ".json"));
        BOOST_REQUIRE_MESSAGE(s.length() > 0, "Contents of " + testPath + "/" + _name + ".json is empty. Have you cloned the 'tests' repo branch develop and set ETHEREUM_TEST_PATH to its path?");
        json_spirit::read_string(s, v);
        Listener::notifySuiteStarted(_name);
        doTests(v, false);
    }
    catch (Exception const& _e)
    {
        BOOST_ERROR("Failed test with Exception: " << diagnostic_information(_e));
    }
    catch (std::exception const& _e)
    {
        BOOST_ERROR("Failed test with Exception: " << _e.what());
    }
}

RLPStream createRLPStreamFromTransactionFields(json_spirit::mObject& _tObj)
{
    //Construct Rlp of the given transaction
    RLPStream rlpStream;
    rlpStream.appendList(_tObj.size());

    if (_tObj.count("nonce"))
        rlpStream << bigint(_tObj["nonce"].get_str());

    if (_tObj.count("gasPrice"))
        rlpStream << bigint(_tObj["gasPrice"].get_str());

    if (_tObj.count("gasLimit"))
        rlpStream << bigint(_tObj["gasLimit"].get_str());

    if (_tObj.count("to"))
    {
        if (_tObj["to"].get_str().empty())
            rlpStream << "";
        else
            rlpStream << importByteArray(_tObj["to"].get_str());
    }

    if (_tObj.count("value"))
        rlpStream << bigint(_tObj["value"].get_str());

    if (_tObj.count("data"))
        rlpStream << importData(_tObj);

    if (_tObj.count("v"))
        rlpStream << bigint(_tObj["v"].get_str());

    if (_tObj.count("r"))
        rlpStream << bigint(_tObj["r"].get_str());

    if (_tObj.count("s"))
        rlpStream <<  bigint(_tObj["s"].get_str());

    if (_tObj.count("extrafield"))
        rlpStream << bigint(_tObj["extrafield"].get_str());

    return rlpStream;
}

Options::Options()
{
    auto argc = boost::unit_test::framework::master_test_suite().argc;
    auto argv = boost::unit_test::framework::master_test_suite().argv;

    for (auto i = 0; i < argc; ++i)
    {
        auto arg = std::string{argv[i]};
        if (arg == "--jit")
        {
            jit = true;
            eth::VMFactory::setKind(eth::VMKind::JIT);
        }
        else if (arg == "--vmtrace")
            vmtrace = true;
        else if (arg == "--filltests")
            fillTests = true;
        else if (arg.compare(0, 7, "--stats") == 0)
        {
            stats = true;
            if (arg.size() > 7)
                statsOutFile = arg.substr(8); // skip '=' char
        }
        else if (arg == "--performance")
            performance = true;
        else if (arg == "--quadratic")
            quadratic = true;
        else if (arg == "--memory")
            memory = true;
        else if (arg == "--inputlimits")
            inputLimits = true;
        else if (arg == "--bigdata")
            bigData = true;
        else if (arg == "--checkstate")
            checkState = true;
        else if (arg == "--all")
        {
            performance = true;
            quadratic = true;
            memory = true;
            inputLimits = true;
            bigData = true;
            checkState = true;
        }
    }
}

Options const& Options::get()
{
    static Options instance;
    return instance;
}


LastHashes lastHashes(u256 _currentBlockNumber)
{
    LastHashes ret;
    for (u256 i = 1; i <= 256 && i <= _currentBlockNumber; ++i)
        ret.push_back(sha3(toString(_currentBlockNumber - i)));
    return ret;
}


namespace
{
    Listener* g_listener;
}

void Listener::registerListener(Listener& _listener)
{
    g_listener = &_listener;
}

void Listener::notifySuiteStarted(std::string const& _name)
{
    if (g_listener)
        g_listener->suiteStarted(_name);
}

void Listener::notifyTestStarted(std::string const& _name)
{
    if (g_listener)
        g_listener->testStarted(_name);
}

void Listener::notifyTestFinished()
{
    if (g_listener)
        g_listener->testFinished();
}

} } // namespaces