Simplify test_can_read_toml_env_variable to work like other tests

[Pierre-Sassoulas]

Type of Changes

	Type
✓	🔨 Refactoring

Description

See initial intent in #3839
This permit to not use the OptionManagerMixin directly, which is
problematic when it needs the function defined in Pylinter or
other classes.

Required for #4720

[coveralls]

Pull Request Test Coverage Report for Build 1441747249

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 93.362%

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Totals
Change from base Build 1439309442:	0.0%
Covered Lines:	13812
Relevant Lines:	14794

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💛 - Coveralls

[DanielNoord]

Looks good (if two minor comments get resolved)!

Btw, I looked at #3839 and #4812 does not seem to test what is reported there imo. When I read that issue report I think the reporter implies that an environment variables is used within the config file. The test created in #4812 doesn't test a config file with env-variables inside the file, but rather when the file itself is a env-variable itself.
Let me know if you think I'm reading the initial report incorrectly, just thought I would let you know :)

[DanielNoord]

This needs typing. I think it is Optional[Set[str]]?

[Pierre-Sassoulas]

Nice catch !

[Pierre-Sassoulas]

doesn't test a config file with env-variables inside the file, but rather when the file itself is a env-variable itself.

Readint this it seems it's the intended use case. But I don't think working env variable directly work. Doing this fail:

diff --git a/tests/config/test_config.py b/tests/config/test_config.py
index 8ce5d9b4..bef53913 100644
--- a/tests/config/test_config.py
+++ b/tests/config/test_config.py
@@ -120,11 +120,12 @@ def test_can_read_toml_env_variable(tmp_path: Path) -> None:
         """
 [tool.pylint."messages control"]
 disable = "logging-not-lazy,logging-format-interpolation"
-jobs = "10"
+jobs = "${pylint_jobs}"
 reports = "yes"
 """
     )
     env_var = "tmp_path_env"
     os.environ[env_var] = str(config_file)
+    os.environ["pylint_jobs"] = "10"
     run = get_runner_from_config_file(f"${env_var}")
     check_configuration_file_reader(run)

[DanielNoord]

Yeah, the test works for with the PR was trying to add but I wonder if that PR should have closed the issue.
In any case, do we want to support environment variables in the config file? If so, we should probably open an issue.

[Pierre-Sassoulas]

do we want to support environment variables in the config file?

We could do it if someone open an issue. But it probably won't happen as we have a bazillion different ways to change options already (one of them being a global file, one of them is calling the command with the env variable directly it supersedes the config file value).