fix: Raise ValueError for unsupported bind_namespace values

This patch changes `NamespaceManager.__init__` to raise a `ValueError`
when it receives an unsupported value for `bind_namespaces`.

Other changes:
- Added a Literal type for valid `bind_namespaces` values, with this
  type checkers will raise an error if an invalid string is supplied as
  an argument.
- Rename some variables/properties to have a underscore in front to make
  it clear they are not part of the RDFLib public API.

rdflib/graph.py

@@ -7,6 +7,7 @@
 from io import BytesIO
 from typing import (
     IO,
+    TYPE_CHECKING,
     Any,
     BinaryIO,
     Generator,
@@ -38,6 +39,9 @@
 assert Literal  # avoid warning
 assert Namespace  # avoid warning
 
+if TYPE_CHECKING:
+    from rdflib.namespace import _NamespaceSetString
+
 logger = logging.getLogger(__name__)
 
 __doc__ = """\
@@ -329,7 +333,7 @@ def __init__(
         identifier: Optional[Union[IdentifiedNode, str]] = None,
         namespace_manager: Optional[NamespaceManager] = None,
         base: Optional[str] = None,
-        bind_namespaces: str = "core",
+        bind_namespaces: "_NamespaceSetString" = "core",
     ):
         super(Graph, self).__init__()
         self.base = base
@@ -344,7 +348,7 @@ def __init__(
         else:
             self.__store = store
         self.__namespace_manager = namespace_manager
-        self.bind_namespaces = bind_namespaces
+        self._bind_namespaces = bind_namespaces
         self.context_aware = False
         self.formula_aware = False
         self.default_union = False
@@ -363,7 +367,7 @@ def namespace_manager(self):
         this graph's namespace-manager
         """
         if self.__namespace_manager is None:
-            self.__namespace_manager = NamespaceManager(self, self.bind_namespaces)
+            self.__namespace_manager = NamespaceManager(self, self._bind_namespaces)
         return self.__namespace_manager
 
     @namespace_manager.setter

rdflib/namespace/__init__.py

@@ -1,5 +1,6 @@
 import json
 import logging
+import sys
 import warnings
 from functools import lru_cache
 from pathlib import Path
@@ -342,6 +343,14 @@ def _ipython_key_completions_(self) -> List[str]:
 
 XMLNS = Namespace("http://www.w3.org/XML/1998/namespace")
 
+if TYPE_CHECKING:
+    if sys.version_info >= (3, 8):
+        from typing import Literal as PyLiteral
+    else:
+        from typing_extensions import Literal as PyLiteral
+
+    _NamespaceSetString = PyLiteral["core", "rdflib", "none"]
+
 
 class NamespaceManager(object):
     """Class for managing prefix => namespace mappings
@@ -386,7 +395,7 @@ class NamespaceManager(object):
 
     """
 
-    def __init__(self, graph: "Graph", bind_namespaces: str = "core"):
+    def __init__(self, graph: "Graph", bind_namespaces: "_NamespaceSetString" = "core"):
         self.graph = graph
         self.__cache: Dict[str, Tuple[str, URIRef, str]] = {}
         self.__cache_strict: Dict[str, Tuple[str, URIRef, str]] = {}
@@ -405,21 +414,23 @@ def __init__(self, graph: "Graph", bind_namespaces: str = "core"):
             pass
         elif bind_namespaces == "rdflib":
             # bind all the Namespaces shipped with RDFLib
-            for prefix, ns in NAMESPACE_PREFIXES_RDFLIB.items():
+            for prefix, ns in _NAMESPACE_PREFIXES_RDFLIB.items():
                 self.bind(prefix, ns)
             # ... don't forget the core ones too
-            for prefix, ns in NAMESPACE_PREFIXES_CORE.items():
+            for prefix, ns in _NAMESPACE_PREFIXES_CORE.items():
                 self.bind(prefix, ns)
         elif bind_namespaces == "cc":
             # bind any prefix that can be found with lookups to prefix.cc
             # first bind core and rdflib ones
             # work out remainder - namespaces without prefixes
             # only look those ones up
             raise NotImplementedError("Haven't got to this option yet")
-        else:  # bind_namespaces == "core":
+        elif bind_namespaces == "core":
             # bind a few core RDF namespaces - default
-            for prefix, ns in NAMESPACE_PREFIXES_CORE.items():
+            for prefix, ns in _NAMESPACE_PREFIXES_CORE.items():
                 self.bind(prefix, ns)
+        else:
+            raise ValueError(f"unsupported namespace set {bind_namespaces}")
 
     def __contains__(self, ref: str) -> bool:
         # checks if a reference is in any of the managed namespaces with syntax
@@ -828,7 +839,7 @@ def get_longest_namespace(trie: Dict[str, Any], value: str) -> Optional[str]:
 from rdflib.namespace._XSD import XSD
 
 # prefixes for the core Namespaces shipped with RDFLib
-NAMESPACE_PREFIXES_CORE = {
+_NAMESPACE_PREFIXES_CORE = {
     "owl": OWL,
     "rdf": RDF,
     "rdfs": RDFS,
@@ -839,7 +850,7 @@ def get_longest_namespace(trie: Dict[str, Any], value: str) -> Optional[str]:
 
 
 # prefixes for all the non-core Namespaces shipped with RDFLib
-NAMESPACE_PREFIXES_RDFLIB = {
+_NAMESPACE_PREFIXES_RDFLIB = {
     "brick": BRICK,
     "csvw": CSVW,
     "dc": DC,

test/test_namespacemanager.py

@@ -1,15 +1,22 @@
+import logging
 import sys
+from contextlib import ExitStack
 from pathlib import Path
+from typing import Any, Dict, Optional, Set, Tuple, Type, Union
 
+import pytest
+
+from rdflib.graph import Dataset
 from rdflib.term import URIRef
 
 sys.path.append(str(Path(__file__).parent.parent.absolute()))
 from rdflib import Graph
 from rdflib.namespace import (
-    NAMESPACE_PREFIXES_CORE,
-    NAMESPACE_PREFIXES_RDFLIB,
+    _NAMESPACE_PREFIXES_CORE,
+    _NAMESPACE_PREFIXES_RDFLIB,
     OWL,
     RDFS,
+    NamespaceManager,
 )
 
 
@@ -18,7 +25,7 @@ def test_core_prefixes_bound():
     g = Graph()
 
     # prefixes in Graph
-    assert len(list(g.namespaces())) == len(NAMESPACE_PREFIXES_CORE)
+    assert len(list(g.namespaces())) == len(_NAMESPACE_PREFIXES_CORE)
     pre = sorted([x[0] for x in list(g.namespaces())])
     assert pre == ["owl", "rdf", "rdfs", "xml", "xsd"]
 
@@ -27,8 +34,8 @@ def test_rdflib_prefixes_bound():
     g = Graph(bind_namespaces="rdflib")
 
     # the core 5 + the extra 23 namespaces with prefixes
-    assert len(list(g.namespaces())) == len(NAMESPACE_PREFIXES_CORE) + len(
-        list(NAMESPACE_PREFIXES_RDFLIB)
+    assert len(list(g.namespaces())) == len(_NAMESPACE_PREFIXES_CORE) + len(
+        list(_NAMESPACE_PREFIXES_RDFLIB)
     )
 
 
@@ -78,3 +85,80 @@ def test_replace():
     assert ("rdfs", URIRef("http://example.com")) in list(
         g.namespace_manager.namespaces()
     )
+
+
+def test_invalid_selector() -> None:
+    graph = Graph()
+    with pytest.raises(ValueError):
+        NamespaceManager(graph, bind_namespaces="invalid")  # type: ignore[arg-type]
+
+
+NamespaceSet = Set[Tuple[str, URIRef]]
+
+
+def check_graph_ns(
+    graph: Graph,
+    expected_nsmap: Dict[str, Any],
+    check_namespaces: Optional[NamespaceSet] = None,
+) -> None:
+    expected_namespaces = {
+        (prefix, URIRef(f"{uri}")) for prefix, uri in expected_nsmap.items()
+    }
+    logging.debug("expected_namespaces = %s", expected_namespaces)
+    graph_namespaces = {*graph.namespaces()}
+    assert expected_namespaces == graph_namespaces
+    nman_namespaces = {*graph.namespace_manager.namespaces()}
+    assert expected_namespaces == nman_namespaces
+    if check_namespaces is not None:
+        assert expected_namespaces == check_namespaces
+        logging.debug("check_namespaces = %s", check_namespaces)
+
+
+@pytest.mark.parametrize(
+    ["selector", "expected_result"],
+    [
+        (None, ValueError),
+        ("invalid", ValueError),
+        ("core", _NAMESPACE_PREFIXES_CORE),
+        ("rdflib", {**_NAMESPACE_PREFIXES_CORE, **_NAMESPACE_PREFIXES_RDFLIB}),
+        ("none", {}),
+    ],
+)
+def test_graph_bind_namespaces(
+    selector: Any,
+    expected_result: Union[Dict[str, Any], Type[Exception]],
+) -> None:
+    namespaces: Optional[NamespaceSet] = None
+    with ExitStack() as xstack:
+        if not isinstance(expected_result, dict):
+            xstack.enter_context(pytest.raises(expected_result))
+        graph = Graph(bind_namespaces=selector)
+        namespaces = {*graph.namespaces()}
+    if isinstance(expected_result, dict):
+        assert namespaces is not None
+        check_graph_ns(graph, expected_result, namespaces)
+    else:
+        assert namespaces is None
+
+
+@pytest.mark.parametrize(
+    ["selector", "expected_result"],
+    [
+        (None, ValueError),
+        ("invalid", ValueError),
+        ("core", _NAMESPACE_PREFIXES_CORE),
+        ("rdflib", {**_NAMESPACE_PREFIXES_CORE, **_NAMESPACE_PREFIXES_RDFLIB}),
+        ("none", {}),
+    ],
+)
+def test_nman_bind_namespaces(
+    selector: Any,
+    expected_result: Union[Dict[str, Any], Type[Exception]],
+) -> None:
+    with ExitStack() as xstack:
+        if not isinstance(expected_result, dict):
+            xstack.enter_context(pytest.raises(expected_result))
+        graph = Dataset()
+        graph.namespace_manager = NamespaceManager(graph, selector)
+    if isinstance(expected_result, dict):
+        check_graph_ns(graph, expected_result)