Introduce "all" and "none" specifiers

src/univers/version_range.py

@@ -19,6 +19,8 @@
 from univers import versions
 from univers.conan.version_range import VersionRange as conan_version_range
 from univers.utils import remove_spaces
+from univers.versions import AllVersion
+from univers.versions import NoneVersion
 from univers.version_constraint import VersionConstraint
 from univers.version_constraint import contains_version
 
@@ -220,6 +222,13 @@ def __contains__(self, version):
         object. A version is contained in a VersionRange if it satisfies its
         constraints according to ``vers`` rules.
         """
+
+        if self.version_class is AllVersion:
+            return True
+
+        if self.version_class is NoneVersion:
+            return False
+
         if not isinstance(version, self.version_class):
             raise TypeError(
                 f"{version!r} is not of expected type: {self.version_class!r}",
@@ -712,9 +721,9 @@ class PypiVersionRange(VersionRange):
     def from_native(cls, string):
         """
         Return a VersionRange built from a PyPI PEP440 version specifiers ``string``.
-        Raise an a univers.versions.InvalidVersion
+        Raise a univers.versions.InvalidVersion
         """
-        # TODO: environment markers are yet supported
+        # TODO: environment markers are not yet supported
         # TODO: handle  .* version, ~= and === operators
 
         if ";" in string:
@@ -1177,6 +1186,16 @@ class MattermostVersionRange(VersionRange):
     version_class = versions.SemverVersion
 
 
+class AllVersionRange(VersionRange):
+    scheme = "all"
+    version_class = versions.AllVersion
+
+
+class NoneVersionRange(VersionRange):
+    scheme = "none"
+    version_class = versions.NoneVersion
+
+
 def from_gitlab_native(gitlab_scheme, string):
     purl_scheme = gitlab_scheme
     if gitlab_scheme not in PURL_TYPE_BY_GITLAB_SCHEME.values():
@@ -1419,6 +1438,8 @@ def build_range_from_snyk_advisory_string(scheme: str, string: Union[str, List])
     "openssl": OpensslVersionRange,
     "mattermost": MattermostVersionRange,
     "conan": ConanVersionRange,
+    "all": AllVersionRange,
+    "none": NoneVersionRange,
 }
 
 PURL_TYPE_BY_GITLAB_SCHEME = {

src/univers/versions.py

@@ -123,7 +123,7 @@ def build_value(self, string):
 
     def satisfies(self, constraint):
         """
-        Return True is this Version satisfies the ``constraint``
+        Return True if this Version satisfies the ``constraint``
         VersionConstraint. Satisfying means that this version is "within" the
         ``constraint``.
         """
@@ -133,6 +133,18 @@ def __str__(self):
         return str(self.value)
 
 
+class AllVersion(Version):
+    @classmethod
+    def is_valid(cls, string):
+        return string == "vers:all/*"
+
+
+class NoneVersion(Version):
+    @classmethod
+    def is_valid(cls, string):
+        return string == "vers:none/*"
+
+
 class GenericVersion(Version):
     @classmethod
     def is_valid(cls, string):

tests/test_version_range.py

@@ -28,6 +28,7 @@
 from univers.versions import PypiVersion
 from univers.versions import RubygemsVersion
 from univers.versions import SemverVersion
+from univers.versions import Version
 
 
 class TestVersionRange(TestCase):
@@ -546,3 +547,23 @@ def test_version_range_normalize_case3():
     nvr = vr.normalize(known_versions=known_versions)
 
     assert str(nvr) == "vers:pypi/>=1.0.0|<=1.3.0|3.0.0"
+
+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/*")    
+    assert not none_vers.contains(Version("1.2.3"))
+    assert PypiVersion("2.0.3") not in none_vers
+    # test for invalid all range specification
+    with pytest.raises(Exception):
+        VersionRange.from_string("vers:none/!1.2.3")
+    with pytest.raises(Exception):
+        VersionRange.from_string("vers:none/*|>1.2.3")