add string equality check for all and none versions

Signed-off-by: Kunz, Immanuel <[email protected]>

src/univers/versions.py

@@ -134,11 +134,15 @@ def __str__(self):
 
 
 class AllVersion(Version):
-    pass
+    @classmethod
+    def is_valid(cls, string):
+        return string == "vers:all/*"
 
 
 class NoneVersion(Version):
-    pass
+    @classmethod
+    def is_valid(cls, string):
+        return string == "vers:none/*"
 
 
 class GenericVersion(Version):

tests/test_version_range.py

@@ -552,6 +552,11 @@ def test_version_range_all():
     all_vers = VersionRange.from_string("vers:all/*")
     assert all_vers.contains(Version("1.2.3"))
     assert PypiVersion("2.0.3") in all_vers
+    # test for invalid all range specification
+    with pytest.raises(Exception):
+        VersionRange.from_string("vers:all/>1.2.3")
+    with pytest.raises(Exception):
+        VersionRange.from_string("vers:all/*|>1.2.3")
 
 def test_version_range_none():
     none_vers = VersionRange.from_string("vers:none/*")