Empty string environment variables are not included during tests

[Zhong-z]

Behaviour

Expected vs. Actual

Expected:

Empty string environment variables are loaded/included when running tests using the extension.

Actual

Empty string environment variables lost completely.

Steps to reproduce:

echo 'export HELLO_WORLD_NOT_EMPTY="123"' >> ~/.zshrc
echo 'export HELLO_WORLD_EMPTY=""' >> ~/.zshrc
source ~/.zshrc

Run the following tests (defined in file test_os_environ.py) in vscode 'testing', configured with pytest,

import os

def test_empty_env_exist():
  assert "HELLO_WORLD_EMPTY" in os.environ.keys()

def test_non_empty_env_exist():
  assert "HELLO_WORLD_NOT_EMPTY" in os.environ.keys()

def test_empty_string_env():
  assert os.environ.get("HELLO_WORLD_EMPTY") == ""

def test_non_empty_string_env():
  assert os.environ.get("HELLO_WORLD_NOT_EMPTY") == "123"

tests with empty string environment fails

and run pytest via CLI, all tests passed

Diagnostic data

• Python version (& distribution if applicable, e.g. Anaconda): 3.10.5
• Type of virtual environment used (e.g. conda, venv, virtualenv, etc.): Venv
• Value of the python.languageServer setting: Default

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

2023-10-26 00:24:59.184 [info] > ./.venv/bin/python -m pytest --rootdir . --override-ini junit_family=xunit1 --junit-xml=/var/folders/7c/l24wyqrs77d5y1d_fvqbvg8r0000gn/T/tmp-10329QUwFJk7Mn728.xml
2023-10-26 00:24:59.184 [info] cwd: .

User Settings

languageServer: "Pylance"

testing
• pytestArgs: "<placeholder>"
• pytestEnabled: true

[eleanorjboyd]

Hello! Can you try this on the testing rewrite and let me know if it still exists? To do so 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!

[eleanorjboyd]

Another note, we do not run anything in a shell for testing so we will not pick up the .zshrc during running tests. Instead how you can do it is run the following as running code . from the terminal window with the environment variables will open the given folder with those environment variables as defined in the .zshrc.

echo 'export HELLO_WORLD_NOT_EMPTY="123"' >> ~/.zshrc
echo 'export HELLO_WORLD_EMPTY=""' >> ~/.zshrc
source ~/.zshrc
code .

[Zhong-z]

Hi @eleanorjboyd, thanks for the responses!

then check for Experiment 'pythonTestAdapter' is active in your python logs.

confirming pythonTestAdapter is active.

---

we do not run anything in a shell for testing so we will not pick up the .zshrc during running tests.

🤔 I considered this as well, that's why I included test cases for the negative scenario HELLO_WORLD_NOT_EMPTY=123. As you can see from the GIF, somehow HELLO_WORLD_NOT_EMPTY is available (indicated by tests passing). but not HELLO_WORLD_EMPTY

---

Instead how you can do it is run the following as running code . from the terminal window with the environment variables will open

Yeah, tried code . as well. Same result.

[eleanorjboyd]

hm yes good point, @karrtikr or @karthiknadig thoughts on why one exists and the other doesn't and also why code . provides the same behavior?

Also @Zhong-z was there a reason you were using your .zshrc for these variables? You could also think about putting them in a .env file and then setting that path via "python.envFile": "${workspaceFolder}/.env" in settings

[karrtikr]

That is strange indeed, maybe VS Code filters out the empty variables, logs should indicate which variables are included when launching tests.

[Zhong-z]

The script/code snippet was simplified for reproducing. In my actual setup/use case, the ENV variables were setup in zshrc/shell is because they are shared between multiple repos/projects (different languages) locally, and they are subjective to change independently.

I could technically use a .env, but it is a pain to manage them separately per repo/copy. shell/.zhsrc is the the simplest way I could think of.

[Zhong-z]

That is strange indeed, maybe VS Code filters out the empty variables, logs should indicate which variables are included when launching tests.

Thanks @karrtikr . I couldn't see the empty string ENVs are included in the 'printEnvVariables.py` output at all, so I assume they are not included.

2023-10-26 09:01:07.678 [debug] Shell Exec: /Users/zz/.pyenv/versions/3.10.5/bin/python /Users/zz/.vscode/extensions/ms-python.python-2023.18.0/pythonFiles/printEnvVariables.py with options: {
    "shell": "/bin/zsh",
    "timeout": 30000,
    "maxBuffer": 1000000,
    "throwOnStdErr": false,
    "encoding": "utf8",
    "env": {
        .....
        "HELLO_WORLD_NOT_EMPTY": "123",

[karrtikr]

@Zhong-z You could add "python.envFile" in User settings, so it applies to all projects. It could carry the global path to a .env file.

[Zhong-z]

Thanks all. It appears that the issue is indeed related to VS Code in general and is not specific to the Python extension. 😄
microsoft/vscode#182560

[eleanorjboyd]

Glad you were able to find the root there- sorry there is nothing we can do to help! Closing this issue as the issue on core will keep track of status and progress. Thanks!

[karrtikr]

Great job finding the upstream issue! FYI #22337 (comment) should still help your case.