README.md

data-and-analytics-etl

Lambda code and testing for the Data & Analytics team's ETL project.

Setting things up locally

To install requirements for this repo, run: pip install -r requirements.txt

Running tests against the repo

Tests in this repo have been implemented with unittest.

To run all tests, in the main directory run: py -m unittest

To run tests from a specific file, run: py -m unittest testing/{file_path}.py

To run tests from a specific class within a file, run: py -m unittest testing.{file_path}.{class_name}

To run a specific test, run: py -m unittest testing.{file_path}.{class_name}.{test_name}

Creating new tests

All new tests should be created in a uniform way to make understanding them easier. First, all test files should be created in the Testing folder or a subfolder of it and have a file name in the format of tests_{name}.py. Next, tests need to be implemented as functions in a class inheriting from unittest.TestCase. Finally, tests should make sure to implement the proper mocks to run properly, and use functions from testing/util.py as needed. A common structure that many current tests take the form of is the following:

import unittest
from testing.util import run_test_cases
...

{implement mocks here}

class TestClass(unittest.TestCase):
    def test_method(self):
        test_data = [
            {
                'name': 'test_case_name',
                'expect_exception': {False/True},
                'exception': {None/Exception('Reason')},
                ...
            },
            ...
        ]

        def test_function(self, test_case):
            {test_body}

        run_test_cases(self, test_data, test_function)

    ...