PytestSetting Project Test System

Internal

• Pytest

Install pytest

Install pytest in the virtual environment associated with your project:

Pytest Installation

Layout

...
 └─ tests
     ├─ data
     ├─ util.py # get_data_file()
     └─ my_module
         └─ test_my_function.py

util.py:

from pathlib import Path

def get_data_file_path(path_rel_to_data):
    """
    Return the resolved path corresponding to path_rel_to_data, which is
    relative to the test 'data' file. The function does not attempt to check
    whether the file or directory exists.
    try to resolve
    :param path_rel_to_data:
    :return: the resolved path
    """
    return str(Path(Path(__file__).parent, './data/' + path_rel_to_data))

Environment

Add the path to the directory that contains the module to test (in this case ./src/main/python contains my_module_to_test.py). In case there is auxiliary code in the tests directory, like util.py, also add "./tests" to the path.

PYTHONPATH="$(dirname $0)/src:${PWD}/tests"
export PYTHONPATH

This can be added to .envrc as follows:

PYTHONPATH="${PWD}/src:${PWD}/tests"
export PYTHONPATH

Structure of a Test File

import pytest
from pathlib import Path
from my_module_to_test import some_function

def get_test_file(file_name):
    return Path(Path(__file__).parent, f'./data/{file_name}')