import os

provided_prefix = os.getenv('MYPY_TEST_PREFIX', None)
if provided_prefix:
    PREFIX = provided_prefix
else:
    this_file_dir = os.path.dirname(os.path.realpath(__file__))
    PREFIX = os.path.dirname(os.path.dirname(this_file_dir))

# Location of test data files such as test case descriptions.
test_data_prefix = os.path.join(PREFIX, 'mypyc', 'test-data')