[pytest] If present, "python.testing.cwd" expected to change `pytest --rootdir` arg value.

Environment data

• VS Code version: 1.41.0
• Extension version (available under the Extensions sidebar): 2020.1.57204
• OS and version: MacOS 10.14.6
• Python version (& distribution if applicable, e.g. Anaconda): 3.7
• Type of virtual environment used (N/A | venv | virtualenv | conda | …): venv
• Relevant/affected Python packages and their versions: pytest-5.2.2
• Jedi or Language Server? (i.e. what is "python.jediEnabled" set to; more info #3977): Language Server

Expected behaviour

When running a test with a settings.json that contains the "python.testing.cwd": "root/dir" option should result in a pytest command that uses "root/dir" as the --rootdir argument. If it is null, then fallback to existing behavior: --rootdir ${workspaceFolder}.

This is necessary for my use case since my code is in a monorepo and loads test fixtures from disk using paths relative to a project root rather than the repo root.

For example,

python [~]/.vscode/extensions/ms-python.python-2020.1.57204/pythonFiles/testing_tools/run_adapter.py discover pytest -- --rootdir root/dir -s --cache-clear [...testfolders]

jfyi, I’ve anonymized [~] and [...testfolders].

Actual behaviour

The "python.testing.cwd" setting has no visible effect on --rootdir. It is always the “workspace folder”, which makes sense given the code I linked to below.

Relevant Code

https://github.com/microsoft/vscode-python/blob/2b6a8f2d439fe9d5e66665ea46d8b690ac9b2c39/src/client/testing/pytest/services/discoveryService.ts#L53

https://github.com/microsoft/vscode-python/blob/2b6a8f2d439fe9d5e66665ea46d8b690ac9b2c39/src/client/testing/pytest/main.ts#L50-L52

https://github.com/microsoft/vscode-python/blob/2b6a8f2d439fe9d5e66665ea46d8b690ac9b2c39/src/client/testing/pytest/main.ts#L19-L20

Steps to reproduce:

[NOTE: Self-contained, minimal reproducing code samples are extremely helpful and will expedite addressing your issue]

1. Open a workspace folder containing python tests that are not in the root directory (i.e. a monorepo).
2. Configure pytest to test a project directory. 2a. configure “python.testing.cwd” in settings.json to the project root.
3. Discover tests and observe that all tests are discovered.
4. Run all tests. 4a. Observe the test session starts and all tests pass that do not need to load fixtures from disk. 4b. Observe the output logs look like this:

python [~]/.vscode/extensions/ms-python.python-2020.1.57204/pythonFiles/testing_tools/run_adapter.py discover pytest -- --rootdir [workspaceFolder] -s --cache-clear [project dir]
============================= test session starts ==============================
platform darwin -- Python 3.7.6, pytest-5.2.2, py-1.8.1, pluggy-0.13.1
rootdir: [workspaceFolder]
plugins: doubles-1.5.3, cov-2.8.1

Logs

Output for Python in the Output panel (View→Output, change the drop-down the upper-right of the Output panel to Python)

XXX

Output from Console under the Developer Tools panel (toggle Developer Tools on under Help; turn on source maps to make any tracebacks be useful by running Enable source map support for extension debugging)

XXX

[ProLoser]

Couldn’t this be fixed by removing --rootdir from optionsWithArgsToRemove?

This way if people wish to override the arg they can.

[dcrystalj]

There is issue in our company we use old pytest v3 and giving --rootdir param is causing problems that we cannot use pytest discovery module. Please add option "python.testing.cwd": null to completely remove --rootdir parameter!