chore: add some more type hints and ignoresadd-nsm-arg-to-path-n3

Sadly the __mul__ dunder is not defined in a way that mypy can find it,
so there are some type errors that arise from using it. I added
`type: ignore` comments for those.

I also added some more type hints, which while not strictly necessary,
does contribute to more complete type hint coverage.

2 files changed, 41 insertions, 10 deletions

diff --git a/rdflib/paths.py b/rdflib/paths.py
index e4a9f95a..9fdd6232 100644
--- a/rdflib/paths.py
+++ b/rdflib/paths.py
@@ -234,7 +234,7 @@ class InvPath(Path):
     def __repr__(self):
         return "Path(~%s)" % (self.arg,)
 
-    def n3(self, namespace_manager: Optional["NamespaceManager"] = None):
+    def n3(self, namespace_manager: Optional["NamespaceManager"] = None) -> str:
         return "^%s" % self.arg.n3(namespace_manager)
 
 
@@ -278,7 +278,7 @@ class SequencePath(Path):
     def __repr__(self):
         return "Path(%s)" % " / ".join(str(x) for x in self.args)
 
-    def n3(self, namespace_manager: Optional["NamespaceManager"] = None):
+    def n3(self, namespace_manager: Optional["NamespaceManager"] = None) -> str:
         return "/".join(a.n3(namespace_manager) for a in self.args)
 
 
@@ -299,7 +299,7 @@ class AlternativePath(Path):
     def __repr__(self):
         return "Path(%s)" % " | ".join(str(x) for x in self.args)
 
-    def n3(self, namespace_manager: Optional["NamespaceManager"] = None):
+    def n3(self, namespace_manager: Optional["NamespaceManager"] = None) -> str:
         return "|".join(a.n3(namespace_manager) for a in self.args)
 
 
@@ -403,7 +403,7 @@ class MulPath(Path):
     def __repr__(self):
         return "Path(%s%s)" % (self.path, self.mod)
 
-    def n3(self, namespace_manager: Optional["NamespaceManager"] = None):
+    def n3(self, namespace_manager: Optional["NamespaceManager"] = None) -> str:
         return "%s%s" % (self.path.n3(namespace_manager), self.mod)
 
 
@@ -436,7 +436,7 @@ class NegatedPath(Path):
     def __repr__(self):
         return "Path(! %s)" % ",".join(str(x) for x in self.args)
 
-    def n3(self, namespace_manager: Optional["NamespaceManager"] = None):
+    def n3(self, namespace_manager: Optional["NamespaceManager"] = None) -> str:
         return "!(%s)" % ("|".join(arg.n3(namespace_manager) for arg in self.args))
 
 
diff --git a/test/test_paths_n3.py b/test/test_paths_n3.py
index dfc8244d..b7834721 100644
--- a/test/test_paths_n3.py
+++ b/test/test_paths_n3.py
@@ -1,7 +1,19 @@
+import logging
+from typing import Union
+
 import pytest
 
 from rdflib import RDF, RDFS, Graph
-from rdflib.paths import OneOrMore, ZeroOrMore, ZeroOrOne
+from rdflib.paths import (
+    AlternativePath,
+    InvPath,
+    MulPath,
+    NegatedPath,
+    OneOrMore,
+    SequencePath,
+    ZeroOrMore,
+    ZeroOrOne,
+)
 
 g = Graph()
 nsm = g.namespace_manager
@@ -22,9 +34,23 @@ nsm = g.namespace_manager
             "rdf:type|rdfs:subClassOf",
         ),
         (-RDF.type, f"!(<{RDF.type}>)", "!(rdf:type)"),
-        (RDFS.subClassOf * ZeroOrMore, f"<{RDFS.subClassOf}>*", "rdfs:subClassOf*"),
-        (RDFS.subClassOf * OneOrMore, f"<{RDFS.subClassOf}>+", "rdfs:subClassOf+"),
-        (RDFS.subClassOf * ZeroOrOne, f"<{RDFS.subClassOf}>?", "rdfs:subClassOf?"),
+        # type errors: Unsupported operand types for * ("URIRef" and "str")
+        # note on type errors: The operator is defined but in an odd place
+        (
+            RDFS.subClassOf * ZeroOrMore,  # type: ignore[operator]
+            f"<{RDFS.subClassOf}>*",
+            "rdfs:subClassOf*",
+        ),
+        (
+            RDFS.subClassOf * OneOrMore,  # type: ignore[operator]
+            f"<{RDFS.subClassOf}>+",
+            "rdfs:subClassOf+",
+        ),
+        (
+            RDFS.subClassOf * ZeroOrOne,  # type: ignore[operator]
+            f"<{RDFS.subClassOf}>?",
+            "rdfs:subClassOf?",
+        ),
         (
             RDF.type / RDFS.subClassOf * "*",
             f"<{RDF.type}>/<{RDFS.subClassOf}>*",
@@ -37,6 +63,11 @@ nsm = g.namespace_manager
         ),
     ],
 )
-def test_paths_n3(path, no_nsm, with_nsm):
+def test_paths_n3(
+    path: Union[InvPath, SequencePath, AlternativePath, MulPath, NegatedPath],
+    no_nsm: str,
+    with_nsm: str,
+) -> None:
+    logging.debug("path = %s", path)
     assert path.n3() == no_nsm
     assert path.n3(nsm) == with_nsm