fix: accept single-point Maven range like [5.0,5.0]

A Maven restriction with identical boundaries is a valid hard requirement
on a single version when both boundaries are inclusive, e.g. [5.0,5.0]
means exactly 5.0. The parser rejected every identical-boundary range
outright, so MavenVersionRange.from_native("[5.0,5.0]") raised
RestrictionParseError instead of resolving to the pinned version.

Reject identical boundaries only when at least one side is exclusive
(an empty set such as (5.0,5.0), [5.0,5.0) or (5.0,5.0]), matching the
behaviour of Apache Maven's own VersionRange parser.

Signed-off-by: Apoorva Verma <vermaapoorva0510@gmail.com>

Author: apoorva-01

src/univers/maven.py

@@ -77,14 +77,19 @@ def __init__(self, spec=None):
         _spec = spec[1:-1].strip()
         if "," in _spec:
             lower_bound, upper_bound = _spec.split(",")
-            if lower_bound and lower_bound == upper_bound:
-                raise RestrictionParseError("Range cannot have identical boundaries: %s" % spec)
 
             self.lower_bound = Version(lower_bound) if lower_bound else None
             self.upper_bound = Version(upper_bound) if upper_bound else None
 
-            if self.lower_bound and self.upper_bound and self.upper_bound < self.lower_bound:
-                raise RestrictionParseError("Range defies version ordering: %s" % spec)
+            if self.lower_bound and self.upper_bound:
+                if self.upper_bound < self.lower_bound:
+                    raise RestrictionParseError("Range defies version ordering: %s" % spec)
+                # Identical boundaries describe a single hard requirement such as
+                # [5.0,5.0] and are only valid when both bounds are inclusive.
+                if self.upper_bound == self.lower_bound and not (
+                    self.lower_bound_inclusive and self.upper_bound_inclusive
+                ):
+                    raise RestrictionParseError("Range cannot have identical boundaries: %s" % spec)
         else:
             # single version restriction
             if not self.lower_bound_inclusive or not self.upper_bound_inclusive:

tests/test_maven_version.py

@@ -98,6 +98,17 @@ def test_inclusive_range(self):
         assert "1.3.1" not in r
         assert "2.0" not in r
 
+    def test_identical_inclusive_boundaries(self):
+        r = Restriction("[5.0,5.0]")
+        assert str(r.lower_bound) == "5.0"
+        assert r.lower_bound_inclusive
+        assert str(r.upper_bound) == "5.0"
+        assert r.upper_bound_inclusive
+
+        assert "4.0" not in r
+        assert "5.0" in r
+        assert "5.1" not in r
+
     def test_exclusive_upper_bound(self):
         r = Restriction("[1.0,2.0)")
         assert str(r.lower_bound) == "1.0"

tests/test_maven_version_range.py

@@ -36,6 +36,13 @@ def test_maven_version_range_from_native_for_pinned_version():
     )
 
 
+def test_maven_version_range_from_native_for_single_point_range():
+    version_range = MavenVersionRange.from_native("[5.0,5.0]")
+    assert version_range == MavenVersionRange(
+        constraints=(VersionConstraint(comparator="=", version=MavenVersion(string="5.0")),)
+    )
+
+
 def test_maven_version_range_from_native_for_illformed_version():
     try:
         MavenVersionRange.from_native("(1.0.0]")