testlauncher.py overwrites sys.path

[ghsme]

Environment data

• VS Code version: 1.44.2
• Extension version (available under the Extensions sidebar): 2020.4.74986
• OS and version: Win 10
• Python version (& distribution if applicable, e.g. Anaconda): 3.8
• Type of virtual environment used: venv

Expected behaviour

sys.path is not modified

Actual behaviour

line 26: sys.path[0] = os.getcwd()
overwrites top entry in the sys.path during unit test debugging (pytest in this case). This leads to errors to find modules that were available on that path. It is not obvious why this behavior as there are no comments, but it seems the intention was to insert cwd at the top of sys.path

Steps to reproduce:

1. Place a module to be tested in a directory that is not workspace directory or any other standard module search path
2. Add .env to the project and include PYTHONPATH with the directory of the module being tested like ./src (PYTHONPATH=./src)
3. Write unit test with pytest. Make sure unit test module imports module being tested
4. Place breakpoint in the unit test.
5. Observe breakpoint never reached and debug console shows error pointing to the import statement

Workaround

Edit testLauncher.py and comment out the offending line or replace with sys.path.insert(0, os.getcwd())

[ancillaryCode]

This broke my test debugging this morning. The workaround fixes it.

[karrtikr]

Thanks for identifying the fix, we can the confirm that it's bug.

[RobertDeRose]

I also have this issue and the workaround did work for me as well!

[fsackur]

For n00bs like me working in a dev container, the default location of testlauncher.py is one of ~/.vscode-server-insiders/extensions/ms-python.python-2020.5.78807/pythonFiles/testlauncher.py or ~/.vscode-server/extensions/ms-python.python-2020.5.78807/pythonFiles/testlauncher.py (substitute the version you have installed)

[eleanorjboyd]

Hello! We have just finished our testing rewrite and are beginning the roll out to users. If you are able, it would be very helpful to know if your issue still exists on the rewrite! To try it yourself, add this setting to your users settings.json "python.experiments.optInto": ["pythonTestAdapter"].

You can confirm you have the rewrite enabled by setting "python.analysis.logLevel": "Trace", in your user settings then check for Experiment 'pythonTestAdapter' is active in your python logs.

Let me know if the rewrite fixes your issue. Thanks!

[github-actions]

Because we have not heard back with the information we requested, we are closing this issue for now. If you are able to provide the info later on, then we will be happy to re-open this issue to pick up where we left off.

Happy Coding!