tests: Add skipped coverages for websockets.py and templating.py using branch=true

[lealre]

Note ℹ️
I don't have a lot of experience, and the idea here is to try to help. Sorry if something seems silly or obvious. Any feedback on how I can improve or suggestions for best practices would be appreciated!

Summary

Regarding the issue #2452

Changes to starlette/websockets.py

This test is designed to skip the if statement at line 106. Specifically, the client_state is set to CONNECTED before calling websocket.accept(), which ensures that the code bypasses the conditional logic meant for the CONNECTING state.

I replicated the first test and mocked the value.

Changes to starlette/templating.py

At line 97, an assertion ensures that either directory or env must be provided, but not both None. Since it's not possible to skip both conditionals (if or elif), I added a # pragma: no cover comment to prevent code coverage from flagging this as untested.

def __init__(
    self,
    directory: str | PathLike[str] | typing.Sequence[str | PathLike[str]] | None = None,
    *,
    context_processors: list[typing.Callable[[Request], dict[str, typing.Any]]] | None = None,
    env: jinja2.Environment | None = None,
    **env_options: typing.Any,
) -> None:
    if env_options:
        warnings.warn(
            "Extra environment options are deprecated. Use a preconfigured jinja2.Environment instead.",
            DeprecationWarning,
        )
    assert jinja2 is not None, "jinja2 must be installed to use Jinja2Templates"  
    assert bool(directory) ^ bool(env), "either 'directory' or 'env' arguments must be passed" # <--------------- Line 97
    self.context_processors = context_processors or []
    if directory is not None:   # <-------------------------------------------- Line 99
        self.env = self._create_env(directory, **env_options)
    elif env is not None:       # <-------------------------------------------- Line 101
        self.env = env

    self._setup_env_defaults(self.env)

EDIT: Another option could be to separate the conditional blocks as shown below, ensuring that all branches are covered and that directory takes precedence over env if both are provided, as the current code behaves.

Regarding the precedence of the directory over env, would it be worth adding this to the documentation?

    def __init__(
        self,
        directory: str | PathLike[str] | typing.Sequence[str | PathLike[str]] | None = None,
        *,
        context_processors: list[typing.Callable[[Request], dict[str, typing.Any]]] | None = None,
        env: jinja2.Environment | None = None,
        **env_options: typing.Any,
    ) -> None:
        if env_options:
            warnings.warn(
                "Extra environment options are deprecated. Use a preconfigured jinja2.Environment instead.",
                DeprecationWarning,
            )
        assert jinja2 is not None, "jinja2 must be installed to use Jinja2Templates"
        assert bool(directory) ^ bool(env), "either 'directory' or 'env' arguments must be passed"
        self.context_processors = context_processors or []
        if env is not None:
            self.env = env
        if directory is not None:
            self.env = self._create_env(directory, **env_options)

        self._setup_env_defaults(self.env)

Checklist

• I understand that this PR may be closed in case there was no previous discussion. (This doesn't apply to typos!)
• I've added a test for each change that was introduced, and I tried as much as possible to make a single atomic change.
• I've updated the documentation accordingly.

[Kludex]

Note ℹ️
I don't have a lot of experience, and the idea here is to try to help. Sorry if something seems silly or obvious. Any feedback on how I can improve or suggestions for best practices would be appreciated!

It's all good. :)

Thanks for the help.

[Kludex]

We don't want to have tests that the only way to reproduce the path is with mocks.

The right way I believe would be to remove the conditional in this case, but I actually think it helps on the understanding of the states there. Can we just have a pragma: no branch there?

[Kludex]

no branch, not no cover 👀

[lealre]

Sorry about that

[Kludex]

Can we have this instead?

Suggested change

	elif env is not None:
	elif env is not None: # pragma: no branch

[Kludex]

Vlw. :)