vscode-python: Argument filtering for pytest fails to handle custom arguments

Issue Type: Bug

I created a fixture in conftest.py that reads at input args to pytest (using pytest_addoption. See code below. When I try and add this option to my settings.json file so that my tests execute properly, it fails with the ERROR: file not found…

Here is my conftest.py file :

import pytest
import os


def pytest_addoption(parser):
    parser.addoption("--config_file", action="store")


@pytest.fixture(scope='session')
def config_file(request):
    config_file_value = request.config.option.config_file
    if config_file_value is None:
        print(f'config_file_value = {config_file_value}')
        pytest.skip()
    elif not os.path.exists(config_file_value):
        print(f'config_file_value = {config_file_value}')
        pytest.skip()
    return config_file_value

And then my settings.json relevant to this:

{
    "python.pythonPath": "/usr/bin/python3",
    "python.testing.unittestEnabled": false,
    "python.testing.nosetestsEnabled": false,
    "python.testing.pytestEnabled": true,
    "python.testing.cwd": "",
    "python.autoComplete.addBrackets": true,
    "python.testing.pytestArgs": [
        "--config_file app/config.json",
    ]
}

And finally the output of the console :

ython /root/.vscode-server-insiders/extensions/ms-python.python-2020.4.76186/pythonFiles/testing_tools/run_adapter.py discover pytest -- --rootdir /root/jetson-task-manager -s --cache-clear --config_file app/config.json
Test Discovery failed: 
Error: ============================= test session starts ==============================
platform linux -- Python 3.6.9, pytest-5.4.2, py-1.5.2, pluggy-0.13.1
rootdir: /root/jetson-task-manager
plugins: forked-0.2, xdist-1.22.1
collected 0 items

============================ no tests ran in 0.06s =============================
ERROR: file not found: --config_file app/config.json


Traceback (most recent call last):
  File "/root/.vscode-server-insiders/extensions/ms-python.python-2020.4.76186/pythonFiles/testing_tools/run_adapter.py", line 22, in <module>
    main(tool, cmd, subargs, toolargs)
  File "/root/.vscode-server-insiders/extensions/ms-python.python-2020.4.76186/pythonFiles/testing_tools/adapter/__main__.py", line 100, in main
    parents, result = run(toolargs, **subargs)
  File "/root/.vscode-server-insiders/extensions/ms-python.python-2020.4.76186/pythonFiles/testing_tools/adapter/pytest/_discovery.py", line 44, in discover
    raise Exception("pytest discovery failed (exit code {})".format(ec))
Exception: pytest discovery failed (exit code 4)

Running pytest version 5.4.2. Feels to me like this option is taken as if it were a file to test, versus an actual argument. Ideas? Am I missing something?

Extension version: 2020.4.76186 VS Code version: Code - Insiders 1.46.0-insider (d487078dc7fc1c276657cadb61b4f63833a8df55, 2020-05-07T16:19:54.327Z) OS version: Windows_NT x64 10.0.18363 Remote OS version: Linux arm64 4.9.140-tegra Remote OS version: Linux arm64 4.9.140-tegra

System Info

Item	Value
CPUs	Intel® Core™ i7-8650U CPU @ 1.90GHz (8 x 2112)
GPU Status	2d_canvas: enabled flash_3d: enabled flash_stage3d: enabled flash_stage3d_baseline: enabled gpu_compositing: enabled multiple_raster_threads: enabled_on oop_rasterization: disabled_off protected_video_decode: enabled rasterization: enabled skia_renderer: disabled_off_ok video_decode: enabled viz_display_compositor: enabled_on viz_hit_test_surface_layer: disabled_off_ok webgl: enabled webgl2: enabled
Load (avg)	undefined
Memory (System)	15.93GB (7.08GB free)
Process Argv
Screen Reader	no
VM	0%

Item	Value
Remote	SSH: jetson
OS	Linux arm64 4.9.140-tegra
CPUs	unknown (6 x 345)
Memory (System)	7.68GB (0.66GB free)
VM	0%

Item	Value
Remote	Container taskmanager:latest (/taskmana…
OS	Linux arm64 4.9.140-tegra
CPUs	unknown (6 x 1420)
Memory (System)	7.68GB (0.66GB free)
VM	0%