Kellabyte's rewind tests using BDD (depends on https://gist.github.com/philsquared/567fdd233d574fe1957d17aff3e5d02c)

rewind-bdd.cpp

SCENARIO("initialize rewind", "[rewind]") {
  GIVEN( "an uninitialised environment") {
        int rc;
        MDB_env *env;
        MDB_dbi dbi;
        MDB_txn *txn;

        WHEN("an environment is created and opened") {
            REQUIRE(SuccessFrom(mdb_env_create(&env)));
            REQUIRE(SuccessFrom(mdb_env_set_mapsize(env, size_t(1048576000))));
            REQUIRE(SuccessFrom(mdb_env_set_maxdbs(env, 1024)));
            REQUIRE(SuccessFrom(mdb_env_open(env, "/tmp", MDB_FIXEDMAP /*|MDB_NOSYNC*/, 0664)));

            AND_WHEN("a transaction is begun") {
                REQUIRE(SuccessFrom(mdb_txn_begin(env, NULL, 0, &txn)));
                REQUIRE(SuccessFrom(mdb_dbi_open(txn, NULL, 0, &dbi)));
                REQUIRE(SuccessFrom(mdb_open(txn, NULL, 0, &dbi)));

                THEN("the transaction can be committed") {
                    REQUIRE(SuccessFrom(mdb_txn_commit(txn)));
                }
            }
        }
        mdb_dbi_close(env, dbi);
        mdb_env_close(env);
    }
}