Add a function which creates a mock instance
of data_dictionary::database.
prepare_expression requires a data_dictionary::database
as an argument, so unit tests for it need something
to pass there. make_data_dictionary_database can
be used to create an instance that is sufficient for tests.
Signed-off-by: Jan Ciolek <jan.ciolek@scylladb.com>
expr_test_utils.hh was a header file with helper methods for
expression tests. All functions were inline, because I didn't
know how to create and link a .cc file in test/boost.
Now the header is split into expr_test_utils.hh and expr_test_utils.cc
and moved to test/lib, which is designed to keep this kind of files.
Signed-off-by: Jan Ciolek <jan.ciolek@scylladb.com>