Tests

Build Artifact Cache Problem

There is a need for a bit of explaination for the structure of these unit and integration tests.

Initially, I had each and every test run nimporter_cli.clean() to remove any previous build artifacts and hashes in order to make sure that they didn't use a cached version which would make the test essentially meaningless.

This works great on Unix platforms. Unfortunately, on Windows, PYDs loaded by Python's process cannot be unloaded. There is actually no way to unload these files during runtime. I thought that Pytest launched a new process for each test but that is not the case.

The significance of this is that Windows blocks anyone from deleting the file while Python is using it, meaning that nimporter_cli.clean() cannot be run in any capacity to delete the cached build artifacts.

My Solution

In order for unit tests to be able to compile a new version of the artifact they need each and every time the tests are run, I did 2 things:

1. Run nimporter_cli.clean() before any tests are run using a conftest.py hook.
2. Ensure all tests build modules and libraries that are unique to them. Make sure no two tests are importing the same module.

As portable as Python code is, there are still some concessions to be made when writing cross-platform code.