I'd try following the instructions from the VS Code Python docs' section on debugging tests, which states:

To customize settings for debugging tests, you can specify "purpose": ["debug-test"] in the launch.json file in the .vscode folder from your workspace. This configuration will be used when you run Test: Debug All Tests, Test: Debug Tests in Current File and Test: Debug Test at Cursor commands.

For example, the configuration below in the launch.json file disables the justMyCode setting for debugging tests:

{
  "name": "Python: Debug Tests",
  "type": "debugpy",
  "request": "launch",
  "program": "${file}",
  "purpose": ["debug-test"],
  "console": "integratedTerminal",
  "justMyCode": false
}

If you have more than one configuration entry with "purpose": ["debug-test"], the first definition will be used since we currently don't support multiple definitions for this request type.

Note: I've also seen older configs floating around that use "request": "test" instead of "purpose": ["debug-test"] (Ex. this), so you can try that if "purpose": ["debug-test"] doesn't work for you.

There also seems to be a "debugStdLib": true property you can use if you want to step into standard library things (source).

There's an open issue ticket where this is apparently not working for version 2023.8.0 of the Python extension (#21249), but it will be fixed in later versions. Also potentially related: Pytest restart debugger works only with code-workspace files #21365.

If you want to enter debugging when running pytest in VSCode and stay at a line of code, you could click 'Debug Test' at the top of the method after selecting the pytest test, as shown in the screenshot:

In addition, "python.testing.pytestArgs": [], in .vscode\settings.json is the folder path of the tested file, for example, my test file is in Test_cc under the a folder.

>      "python.testing.pytestArgs": [
>             "a/Test_cc"
>         ],

If this is not what you want, please let me know and describe the details of your needs.

Reference: Debug tests.

Update:

Usually, when we debug the test in VSCode, without setting a breakpoint for it, it will only display the test result. (success or failure). It will only display relevant test information in the console OUTPUT.

When I use the extension 'Python Test Explorer for Visual Studio code', it will display the debugging test information on the console, prompting the issue.

Just adding "justMyCode": false to launch.json doesn't work. You need to add a separate config in launch.json like below. FYI each {} represents a config.

"configurations": [
        {
           .... # existing config
        },
        {
            "name": "Debug Unit Test",
            "type": "python",
            "request": "test",
            "justMyCode": false,
        }
    ]

As pointed out in here

pytest-env

Install

Per https://stackoverflow.com/a/39162893/13697228:

conda install -c conda-forge pytest-env

Or:

pip install pytest-env

pytest.ini

Create pytest.ini file in project directory:

[pytest]
env = 
    ENV_VAR=RandomStuff

Python

In your code, load environment variables as you normally would:

import os
env_var = os.environ["ENV_VAR"]

pytest / VS Code

Either run:

pytest

(Notice how it says configfile: pytest.ini)

C:\Users\sterg\Documents\GitHub\sparks-baird\mp-time-split> pytest
==================================== test session starts ===================================== platform win32 -- Python 3.9.12, pytest-7.1.1, pluggy-1.0.0 rootdir:
C:\Users\sterg\Documents\GitHub\sparks-baird\mp-time-split,
configfile: pytest.ini plugins: anyio-3.6.1, cov-3.0.0, env-0.6.2
collecting ...

Or:

This only seems to work with breakpoints that have manually been set, I'm guessing some other change is needed to pause on errors.

Python for VS Code Extension

Apparently the Python for VS Code extension recognizes a .env file automatically. E.g. .env file:

ENV_VAR=RandomStuff

Haven't verified, but I'd assume this has the same behavior as using pytest-env with a pytest.ini file.

When all else fails

When I don't feel like dealing with the strange hackery necessary to get VS Code, Anaconda environments, and pytest playing nicely together (and/or forget how I fixed it before), I call my tests manually and run it like a normal script (see below). This may not work with more advanced pytest trickery using fixtures for example. At the end of your Python script, you can add something like:

if __name__ == "__main__":
    my_first_test()
    my_second_test()

and run it in debug mode (F5) as normal.