Accept legacy PyPI local versions like 2.0.1rc2-git

Signed-off-by: Aditya kumar singh <143548997+Adityakk9031@users.noreply.github.com>

Author: Adityakk9031

src/univers/versions.py

@@ -217,18 +217,52 @@ def build_value(cls, string):
         """
         Return a packaging.version.LegacyVersion or packaging.version.Version
         """
-        return packaging_version.Version(string)
+        return cls._coerce_pep440(string)
 
     @classmethod
     def is_valid(cls, string):
         try:
             # Note: we consider only modern pep440 versions as valid. legacy
             # will fail validation for now.
-            cls.build_value(string)
+            cls._coerce_pep440(string)
             return True
         except packaging_version.InvalidVersion:
             return False
 
+    @classmethod
+    def _coerce_pep440(cls, string):
+        """
+        Return a packaging.version.Version, coercing a limited set of
+        legacy PyPI version forms that use '-' for a local version segment.
+        """
+        try:
+            return packaging_version.Version(string)
+        except packaging_version.InvalidVersion:
+            normalized = cls._normalize_legacy_local(string)
+            if normalized:
+                return packaging_version.Version(normalized)
+            raise
+
+    @classmethod
+    def _normalize_legacy_local(cls, string):
+        """
+        Normalize legacy local versions like "2.0.1rc2-git" to
+        PEP 440-compatible "2.0.1rc2+git" when safe.
+        """
+        if not string or "+" in string or "-" not in string:
+            return None
+
+        base, local = string.rsplit("-", 1)
+        if not local or not local[0].isalpha():
+            return None
+
+        candidate = f"{base}+{local}"
+        try:
+            packaging_version.Version(candidate)
+        except packaging_version.InvalidVersion:
+            return None
+        return candidate
+
 
 class EnhancedSemanticVersion(semantic_version.Version):
     @property

tests/test_pypi_version.py

@@ -21,6 +21,10 @@ def test_constructor(self):
         assert pypi_version.value == packaging_version.Version("2.4.5")
         self.assertRaises(InvalidVersion, PypiVersion, "2.//////")
 
+    def test_constructor_accepts_legacy_local(self):
+        pypi_version = PypiVersion("2.0.1rc2-git")
+        assert str(pypi_version) == "2.0.1rc2+git"
+
     def test_compare(self):
         pypi_version = PypiVersion("2.4.5")
         assert pypi_version == PypiVersion("2.4.5")

tests/test_versions.py

@@ -39,6 +39,7 @@ def test_pypi_version():
     assert PypiVersion("1.2.3") != PypiVersion("1.2.4")
     assert PypiVersion("1") == PypiVersion("1.0")
     assert PypiVersion.is_valid("1.2.3")
+    assert PypiVersion.is_valid("2.0.1rc2-git")
     assert not PypiVersion.is_valid("1.2.3a-1-a")
     assert PypiVersion.normalize("v1.2.3") == "1.2.3"
     assert PypiVersion("1").satisfies(