Allow braced range syntax in internal sections of tox.ini file

docs/changelog/3571.bugfix.rst

@@ -0,0 +1,2 @@
+Expand braced range syntax in all internal sections of ``tox.ini`` (e.g. ``deps``, ``testenv``). Syntax like py3{10-14} can be used in those sections now.
+- by :user:`marcosboger`

docs/config.rst

@@ -1663,6 +1663,12 @@ Both enumerations (``{1,2,3}``) and numerical ranges (``{1-3}``) are supported,
     [tox]
     env_list = py3{8-10, 11, 13-14}
 
+    [testenv]
+    deps =
+        py{310,311-314}: urllib3
+    setenv =
+        py{310,311-314}: FOO=bar
+
 will create the following envs:
 
 .. code-block:: shell

src/tox/config/loader/ini/factor.py

@@ -64,6 +64,7 @@ def expand_factors(value: str) -> Iterator[tuple[list[list[tuple[str, bool]]] |
 
 def find_factor_groups(value: str) -> Iterator[list[tuple[str, bool]]]:
     """Transform '{py,!pi}-{a,b},c' to [{'py', 'a'}, {'py', 'b'}, {'pi', 'a'}, {'pi', 'b'}, {'c'}]."""
+    value = expand_ranges(value)
     for env in expand_env_with_negation(value):
         result = [name_with_negate(f) for f in env.split("-")]
         yield result

src/tox/config/loader/str_convert.py

@@ -10,7 +10,6 @@
 from typing import TYPE_CHECKING, Any
 
 from tox.config.loader.convert import Convert
-from tox.config.loader.ini.factor import expand_ranges
 from tox.config.types import Command, EnvList
 
 if TYPE_CHECKING:
@@ -115,7 +114,6 @@ def to_command(value: str) -> Command | None:
     def to_env_list(value: str) -> EnvList:
         from tox.config.loader.ini.factor import extend_factors  # noqa: PLC0415
 
-        value = expand_ranges(value)
         elements = list(chain.from_iterable(extend_factors(expr) for expr in value.split("\n")))
         return EnvList(elements)
 

src/tox/config/source/ini_section.py

@@ -1,6 +1,6 @@
 from __future__ import annotations
 
-from tox.config.loader.ini.factor import expand_ranges, extend_factors
+from tox.config.loader.ini.factor import extend_factors
 from tox.config.loader.section import Section
 
 
@@ -15,7 +15,7 @@ def is_test_env(self) -> bool:
 
     @property
     def names(self) -> list[str]:
-        return list(extend_factors(expand_ranges(self.name)))
+        return list(extend_factors(self.name))
 
 
 TEST_ENV_PREFIX = "testenv"

tests/config/loader/ini/test_factor.py

@@ -273,6 +273,40 @@ def test_ini_loader_raw_with_factors(
     assert outcome == result
 
 
+def test_generative_ranges_in_deps(tox_ini_conf: ToxIniCreator) -> None:
+    config = tox_ini_conf(
+        """
+        [testenv]
+        deps-x =
+            py{310-314}: black
+        """,
+    )
+    assert list(config) == ["py310", "py311", "py312", "py313", "py314"]
+
+
+def test_generative_ranges_in_deps_with_mixed_approach(tox_ini_conf: ToxIniCreator) -> None:
+    config = tox_ini_conf(
+        """
+        [testenv]
+        deps-x =
+            py3{10-14}: black
+        """,
+    )
+    assert list(config) == ["py310", "py311", "py312", "py313", "py314"]
+
+
+def test_generative_ranges_in_setenv(tox_ini_conf: ToxIniCreator) -> None:
+    config = tox_ini_conf(
+        """
+        [testenv]
+        setenv =
+            foo{1,2}: FOO=bar
+            foo{3-5}: FOO=baz
+        """,
+    )
+    assert list(config) == ["foo1", "foo2", "foo3", "foo4", "foo5"]
+
+
 def test_generative_section_name_with_ranges(tox_ini_conf: ToxIniCreator) -> None:
     config = tox_ini_conf(
         """