Support recursive extras defined in pyproject.toml (#2905)

* test_package_pyproject: recursive extras

Add regression test for issue #2904

* test_package_pyproject: when project deps has a self-referential extra

the project depends on an extra defined within itself

* Support recursive extras defined in pyproject.toml

Expand extras that reference an extra of the same package name to respect local
changes to package metadata.

Fix #2904

1 files changed, 52 insertions, 0 deletions

diff --git a/tests/tox_env/python/virtual_env/package/test_package_pyproject.py b/tests/tox_env/python/virtual_env/package/test_package_pyproject.py
index a8f6c9ed..0d6160a5 100644
--- a/tests/tox_env/python/virtual_env/package/test_package_pyproject.py
+++ b/tests/tox_env/python/virtual_env/package/test_package_pyproject.py
@@ -1,6 +1,7 @@
 from __future__ import annotations
 
 from pathlib import Path
+from textwrap import dedent
 
 import pytest
 
@@ -92,6 +93,57 @@ def test_package_root_via_testenv(tox_project: ToxProjectCreator, demo_pkg_inlin
             ["A"],
             id="deps_with_dynamic_optional_no_extra",
         ),
+        pytest.param(
+            dedent(
+                """
+                [project]
+                name='foo'
+                dependencies=['foo[alpha]']
+                optional-dependencies.alpha=['A']""",
+            ),
+            "",
+            ["A"],
+            id="deps_reference_extra",
+        ),
+        pytest.param(
+            dedent(
+                """
+                [project]
+                name='foo'
+                dependencies=['A']
+                optional-dependencies.alpha=['B']
+                optional-dependencies.beta=['foo[alpha]']""",
+            ),
+            "beta",
+            ["A", "B"],
+            id="deps_with_recursive_extra",
+        ),
+        pytest.param(
+            dedent(
+                """
+                [project]
+                name='foo'
+                dependencies=['A']
+                optional-dependencies.alpha=['B']
+                optional-dependencies.beta=['foo[alpha]']
+                optional-dependencies.delta=['foo[beta]', 'D']""",
+            ),
+            "delta",
+            ["A", "B", "D"],
+            id="deps_with_two_recursive_extra",
+        ),
+        pytest.param(
+            dedent(
+                """
+                [project]
+                name='foo'
+                optional-dependencies.alpha=['foo[beta]', 'A']
+                optional-dependencies.beta=['foo[alpha]', 'B']""",
+            ),
+            "alpha",
+            ["A", "B"],
+            id="deps_with_circular_recursive_extra",
+        ),
     ],
 )
 def test_pyproject_deps_from_static(