Accept environments with defined factors or of python selector form - suggest closest

docs/changelog/3099.feature.rst

@@ -0,0 +1,3 @@
+Change accepted environment name rule: must be made up of factors defined in configuration or match regex
+``(pypy|py|cython|)((\d(\.\d+(\.\d+)?)?)|\d+)?``. If an environment name does not match this fail, and if a close match
+found suggest that to the user.

src/tox/session/env_select.py

@@ -4,6 +4,7 @@
 import re
 from collections import Counter
 from dataclasses import dataclass
+from difflib import get_close_matches
 from itertools import chain
 from typing import TYPE_CHECKING, Dict, Iterable, Iterator, List, cast
 
@@ -117,6 +118,10 @@ class _ToxEnvInfo:
     package_skip: tuple[str, Skip] | None = None  #: if set the creation of the packaging environment failed
 
 
+_DYNAMIC_ENV_FACTORS = re.compile(r"(pypy|py|cython|)((\d(\.\d+(\.\d+)?)?)|\d+)?")
+_PY_PRE_RELEASE_FACTOR = re.compile(r"alpha|beta|rc\.\d+")
+
+
 class EnvSelector:
     def __init__(self, state: State) -> None:
         # needs core to load the default tox environment list
@@ -152,21 +157,50 @@ def _collect_names(self) -> Iterator[tuple[Iterable[str], bool]]:
         elif self._cli_envs.is_all:
             everything_active = True
         else:
-            cli_envs_not_in_config = set(self._cli_envs) - set(self._state.conf)
-            if cli_envs_not_in_config:
-                # allow cli_envs matching ".pkg" and starting with "py" to be implicitly created.
-                disallowed_cli_envs = [
-                    env for env in cli_envs_not_in_config if not env.startswith("py") and env not in (".pkg",)
-                ]
-                if disallowed_cli_envs:
-                    msg = f"provided environments not found in configuration file: {disallowed_cli_envs}"
-                    raise HandledError(msg)
+            self._ensure_envs_valid()
             yield self._cli_envs, True
         yield self._state.conf, everything_active
         label_envs = dict.fromkeys(chain.from_iterable(self._state.conf.core["labels"].values()))
         if label_envs:
             yield label_envs.keys(), False
 
+    def _ensure_envs_valid(self) -> None:
+        valid_factors = set(chain.from_iterable(env.split("-") for env in self._state.conf))
+        valid_factors.add(".pkg")  # packaging factor
+        invalid_envs: dict[str, str | None] = {}
+        for env in self._cli_envs or []:
+            if env.startswith(".pkg_external"):  # external package
+                continue
+            factors: dict[str, str | None] = {k: None for k in env.split("-")}
+            found_factors: set[str] = set()
+            for factor in factors:
+                if (
+                    _DYNAMIC_ENV_FACTORS.fullmatch(factor)
+                    or _PY_PRE_RELEASE_FACTOR.fullmatch(factor)
+                    or factor in valid_factors
+                ):
+                    found_factors.add(factor)
+                else:
+                    closest = get_close_matches(factor, valid_factors, n=1)
+                    factors[factor] = closest[0] if closest else None
+            if set(factors) - found_factors:
+                invalid_envs[env] = (
+                    None
+                    if any(i is None for i in factors.values())
+                    else "-".join(cast(Iterable[str], factors.values()))
+                )
+        if invalid_envs:
+            msg = "provided environments not found in configuration file:\n"
+            first = True
+            for env, suggestion in invalid_envs.items():
+                if not first:
+                    msg += "\n"
+                first = False
+                msg += env
+                if suggestion:
+                    msg += f" - did you mean {suggestion}?"
+            raise HandledError(msg)
+
     def _env_name_to_active(self) -> dict[str, bool]:
         env_name_to_active_map = {}
         for a_collection, is_active in self._collect_names():

tests/session/test_env_select.py

@@ -1,11 +1,12 @@
 from __future__ import annotations
 
+import sys
 from typing import TYPE_CHECKING
 
 import pytest
 
 from tox.config.cli.parse import get_options
-from tox.session.env_select import CliEnv, EnvSelector
+from tox.session.env_select import _DYNAMIC_ENV_FACTORS, CliEnv, EnvSelector
 from tox.session.state import State
 
 if TYPE_CHECKING:
@@ -150,17 +151,98 @@ def test_cli_env_can_be_specified_in_additional_environments(tox_project: ToxPro
     assert not outcome.err
 
 
-def test_cli_env_not_in_tox_config_fails(tox_project: ToxProjectCreator) -> None:
-    proj = tox_project({"tox.ini": ""})
-    outcome = proj.run("r", "-e", "does_not_exist")
-    outcome.assert_failed(code=-2)
-    assert "provided environments not found in configuration file: ['does_not_exist']" in outcome.out, outcome.out
-
-
 @pytest.mark.parametrize("env_name", ["py", "py310", ".pkg"])
 def test_allowed_implicit_cli_envs(env_name: str, tox_project: ToxProjectCreator) -> None:
     proj = tox_project({"tox.ini": ""})
     outcome = proj.run("r", "-e", env_name)
     outcome.assert_success()
     assert env_name in outcome.out
     assert not outcome.err
+
+
+@pytest.mark.parametrize("env_name", ["a", "b", "a-b", "b-a"])
+def test_matches_hyphenated_env(env_name: str, tox_project: ToxProjectCreator) -> None:
+    tox_ini = """
+        [tox]
+        env_list=a-b
+        [testenv]
+        package=skip
+        commands_pre =
+            a: python -c 'print("a")'
+            b: python -c 'print("b")'
+        commands=python -c 'print("ok")'
+    """
+    proj = tox_project({"tox.ini": tox_ini})
+    outcome = proj.run("r", "-e", env_name)
+    outcome.assert_success()
+    assert env_name in outcome.out
+    assert not outcome.err
+
+
+_MINOR = sys.version_info.minor
+
+
+@pytest.mark.parametrize(
+    "env_name",
+    [f"3.{_MINOR}", f"3.{_MINOR}-cov", "3-cov", "3", f"3.{_MINOR}", f"py3{_MINOR}-cov", f"py3.{_MINOR}-cov"],
+)
+def test_matches_combined_env(env_name: str, tox_project: ToxProjectCreator) -> None:
+    tox_ini = """
+        [testenv]
+        package=skip
+        commands =
+            !cov: python -c 'print("without cov")'
+            cov: python -c 'print("with cov")'
+    """
+    proj = tox_project({"tox.ini": tox_ini})
+    outcome = proj.run("r", "-e", env_name)
+    outcome.assert_success()
+    assert env_name in outcome.out
+    assert not outcome.err
+
+
+@pytest.mark.parametrize(
+    "env",
+    [
+        "py",
+        "pypy",
+        "pypy3",
+        "pypy3.12",
+        "pypy312",
+        "py3",
+        "py3.12",
+        "py312",
+        "3",
+        "3.12",
+        "3.12.0",
+    ],
+)
+def test_dynamic_env_factors_match(env: str) -> None:
+    assert _DYNAMIC_ENV_FACTORS.fullmatch(env)
+
+
+@pytest.mark.parametrize(
+    "env",
+    [
+        "cy3",
+        "cov",
+        "py10.1",
+    ],
+)
+def test_dynamic_env_factors_not_match(env: str) -> None:
+    assert not _DYNAMIC_ENV_FACTORS.fullmatch(env)
+
+
+def test_suggest_env(tox_project: ToxProjectCreator) -> None:
+    tox_ini = f"[testenv:release]\n[testenv:py3{_MINOR}]\n[testenv:alpha-py3{_MINOR}]\n"
+    proj = tox_project({"tox.ini": tox_ini})
+    outcome = proj.run("r", "-e", f"releas,p3{_MINOR},magic,alph-p{_MINOR}")
+    outcome.assert_failed(code=-2)
+
+    assert not outcome.err
+    msg = (
+        "ROOT: HandledError| provided environments not found in configuration file:\n"
+        f"releas - did you mean release?\np3{_MINOR} - did you mean py3{_MINOR}?\nmagic\n"
+        f"alph-p{_MINOR} - did you mean alpha-py3{_MINOR}?\n"
+    )
+    assert outcome.out == msg