fix: add `__hash__` and `__eq__` back to `rdflib.paths.Path` (#2292)

These methods were removed when `@total_ordering` was added, but
`@total_ordering` does not add them, so removing them essentially
removes functionality.

This change adds the methods back and adds tests to ensure they work
correctly.

All path related tests are also moved into one file.

- Closes <https://github.com/RDFLib/rdflib/issues/2281>.
- Closes <https://github.com/RDFLib/rdflib/issues/2242>.

3 files changed, 51 insertions, 9 deletions

diff --git a/rdflib/paths.py b/rdflib/paths.py
index defd0e75..6ca42d74 100644
--- a/rdflib/paths.py
+++ b/rdflib/paths.py
@@ -229,6 +229,12 @@ class Path(object):
     ) -> Iterator[Tuple["_SubjectType", "_ObjectType"]]:
         raise NotImplementedError()
 
+    def __hash__(self):
+        return hash(repr(self))
+
+    def __eq__(self, other):
+        return repr(self) == repr(other)
+
     def __lt__(self, other: Any) -> bool:
         if not isinstance(other, (Path, Node)):
             raise TypeError(
diff --git a/test/test_mulpath_n3.py b/test/test_mulpath_n3.py
deleted file mode 100644
index 41885361..00000000
--- a/test/test_mulpath_n3.py
+++ /dev/null
@@ -1,8 +0,0 @@
-from rdflib import URIRef
-from rdflib.paths import ZeroOrMore
-
-
-def test_mulpath_n3():
-    uri = "http://example.com/foo"
-    n3 = (URIRef(uri) * ZeroOrMore).n3()
-    assert n3 == "<" + uri + ">*"
diff --git a/test/test_paths_n3.py b/test/test_path.py
index b7834721..ad967849 100644
--- a/test/test_paths_n3.py
+++ b/test/test_path.py
@@ -3,13 +3,15 @@ from typing import Union
 
 import pytest
 
-from rdflib import RDF, RDFS, Graph
+from rdflib import RDF, RDFS, Graph, URIRef
+from rdflib.namespace import DCAT, DCTERMS
 from rdflib.paths import (
     AlternativePath,
     InvPath,
     MulPath,
     NegatedPath,
     OneOrMore,
+    Path,
     SequencePath,
     ZeroOrMore,
     ZeroOrOne,
@@ -71,3 +73,45 @@ def test_paths_n3(
     logging.debug("path = %s", path)
     assert path.n3() == no_nsm
     assert path.n3(nsm) == with_nsm
+
+
+def test_mulpath_n3():
+    uri = "http://example.com/foo"
+    n3 = (URIRef(uri) * ZeroOrMore).n3()
+    assert n3 == "<" + uri + ">*"
+
+
+@pytest.mark.parametrize(
+    ["lhs", "rhs"],
+    [
+        (DCTERMS.temporal / DCAT.endDate, DCTERMS.temporal / DCAT.endDate),
+        (SequencePath(DCTERMS.temporal, DCAT.endDate), DCTERMS.temporal / DCAT.endDate),
+    ],
+)
+def test_eq(lhs: Path, rhs: Path) -> None:
+    logging.debug("lhs = %s/%r, rhs = %s/%r", type(lhs), lhs, type(rhs), rhs)
+    assert lhs == rhs
+
+
+@pytest.mark.parametrize(
+    ["lhs", "rhs"],
+    [
+        (DCTERMS.temporal / DCAT.endDate, DCTERMS.temporal / DCAT.endDate),
+        (SequencePath(DCTERMS.temporal, DCAT.endDate), DCTERMS.temporal / DCAT.endDate),
+    ],
+)
+def test_hash(lhs: Path, rhs: Path) -> None:
+    logging.debug("lhs = %s/%r, rhs = %s/%r", type(lhs), lhs, type(rhs), rhs)
+    assert hash(lhs) == hash(rhs)
+
+
+@pytest.mark.parametrize(
+    ["insert_path", "check_path"],
+    [
+        (DCTERMS.temporal / DCAT.endDate, DCTERMS.temporal / DCAT.endDate),
+        (SequencePath(DCTERMS.temporal, DCAT.endDate), DCTERMS.temporal / DCAT.endDate),
+    ],
+)
+def test_dict_key(insert_path: Path, check_path: Path) -> None:
+    d = {insert_path: "foo"}
+    assert d[check_path] == "foo"