toxfile.py

"""Add a couple of useful tweaks to tox. Firstly, support a TOX_RUN_COMMANDS_PRE environment variable,
so that the user can initialize tox environments without running the tests with the combination
TOX_RUN_COMMANDS_PRE tox run -e {toxenv} --notest
This is needed because we set up poetry in our commands_pre step, which is ordinarily skipped with
--notest.
Secondly, use a vendored tox-ignore-env-name-mismatch to allow tox envs to share the same virtual
env and save a TON of space and time. Add the config "remove_factor_from_env" to programmatically
remove a factor from an environment's directory, so eg for short/long tests we share the same venv.
"""

import os
import re
from contextlib import contextmanager
from pathlib import Path
from typing import Any, Iterator, Optional, Sequence, Tuple

from tox.config.of_type import ConfigConstantDefinition
from tox.execute.request import StdinSource
from tox.plugin import impl
from tox.tox_env.api import ToxEnv
from tox.tox_env.info import Info
from tox.tox_env.python.virtual_env.runner import VirtualEnvRunner
from tox.tox_env.register import ToxEnvRegister


@impl
def tox_add_env_config(env_conf, state):
    env_conf.add_config("remove_factor_from_env", str, None, "")
    if env_conf["remove_factor_from_env"] is None:
        return
    factors = env_conf["remove_factor_from_env"].split("\n")
    for factor in factors:
        for target in ("env_dir", "change_dir", "env_tmp_dir", "env_log_dir"):
            new_env_dir = Path(re.sub(f"(.*)-{factor}", r"\1", str(env_conf[target])))
            env_conf._defined[target] = ConfigConstantDefinition((target,), "", new_env_dir)


@impl
def tox_on_install(tox_env, arguments, section, of_type):
    if os.getenv("TOX_RUN_COMMANDS_PRE") == "1":
        for cmd in tox_env.conf["commands_pre"]:
            tox_env.execute(cmd=cmd.args, stdin=StdinSource.user_only(), show=True, cwd=Path.cwd())


"""
tox-ignore-env-name-mismatch, adapted from:
https://github.com/masenf/tox-ignore-env-name-mismatch/blob/ebed15982e30840767d6393913ad507c5d8f5642/src/tox_ignore_env_name_mismatch.py

MIT License
Copyright (c) 2023 Masen Furer
"""


class FilteredInfo(Info):
    """Subclass of Info that optionally filters specific keys during compare()."""

    def __init__(
        self,
        *args: Any,
        filter_keys: Optional[Sequence[str]] = None,
        filter_section: Optional[str] = None,
        **kwargs: Any,
    ):
        """
        :param filter_keys: key names to pop from value
        :param filter_section: if specified, only pop filter_keys when the compared section matches

        All other args and kwargs are passed to super().__init__
        """
        self.filter_keys = filter_keys
        self.filter_section = filter_section
        super().__init__(*args, **kwargs)

    @contextmanager
    def compare(
        self,
        value: Any,
        section: str,
        sub_section: Optional[str] = None,
    ) -> Iterator[Tuple[bool, Optional[Any]]]:
        """Perform comparison and update cached info after filtering `value`."""
        if self.filter_section is None or section == self.filter_section:
            try:
                value = value.copy()
            except AttributeError:  # pragma: no cover
                pass
            else:
                for fkey in self.filter_keys or []:
                    value.pop(fkey, None)
        with super().compare(value, section, sub_section) as rv:
            yield rv


class IgnoreEnvNameMismatchVirtualEnvRunner(VirtualEnvRunner):
    """EnvRunner that does NOT save the env name as part of the cached info."""

    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)

    @staticmethod
    def id() -> str:
        return "ignore_env_name_mismatch"

    @property
    def cache(self) -> Info:
        """Return a modified Info class that does NOT pass "name" key to `Info.compare`."""
        return FilteredInfo(
            self.env_dir,
            filter_keys=["name"],
            filter_section=ToxEnv.__name__,
        )


@impl
def tox_register_tox_env(register: ToxEnvRegister) -> None:
    """tox4 entry point: add IgnoreEnvNameMismatchVirtualEnvRunner to registry."""
    register.add_run_env(IgnoreEnvNameMismatchVirtualEnvRunner)