{TypeCheck,SubjectType,PredicateType,ObjectType}Error and related are not being used

[aucampia]

I was going through tests and found that tests in test/type_check.py were not being run, but also, if I try and run them they fail, even if I fix the constructor parameters (see end of this issue for output).

I looked into this a bit and as far as I can tell (TypeCheck|SubjectType|PredicateType|ObjectType)Error and check_(context|subject|predicate|object|statement|pattern) is not being raised at all, I confirmed this by removing the functions and running tests and type checking - see changes: #1640

I also checked with grep after removing the exceptions and functions, and nothing matches:

$ egrep -ri -e '(TypeCheck|SubjectType|PredicateType|ObjectType)Error' -e 'check_(context|subject|predicate|object|statement|pattern)' rdflib/ examples/ test/ || echo NO MATCHES
NO MATCHES

I think it may be best to just remove all of these exceptions and functions, at the very least we should either fix or remove the tests test/type_check.py.

Any input/feedback on this matter will be apreciated.

output

$ git log -1 --oneline
43d86224 (HEAD, upstream/master, gjhiggins/master, iwana-20211231T0217-flake8_strict) Merge pull request #1630 from aucampia/iwana-20211229T0112-fix_version
$ git diff
diff --git a/test/type_check.py b/test/type_check.py
index 19329a39..34a8d956 100644
--- a/test/type_check.py
+++ b/test/type_check.py
@@ -17,7 +17,7 @@ class TypeCheckCase(unittest.TestCase):
     path = "store"
 
     def setUp(self):
-        self.store = Graph(backend=self.backend)
+        self.store = Graph(store=self.backend)
         self.store.open(self.path)
 
     def tearDown(self):
$ .venv/bin/python3 -m pytest test/type_check.py 
============================================================================ test session starts ============================================================================
platform linux -- Python 3.8.12, pytest-6.2.5, py-1.11.0, pluggy-1.0.0
rootdir: /home/iwana/sw/d/github.com/iafork/rdflib, configfile: setup.cfg
plugins: subtests-0.5.0, cov-3.0.0
collected 3 items                                                                                                                                                           

test/type_check.py FFF                                                                                                                                                [100%]

================================================================================= FAILURES ==================================================================================
_____________________________________________________________________ TypeCheckCase.testObjectTypeCheck _____________________________________________________________________

self = <test.type_check.TypeCheckCase testMethod=testObjectTypeCheck>

    def testObjectTypeCheck(self):
>       self.assertRaises(ObjectTypeError, self.store.add, (foo, foo, None))

test/type_check.py:33: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

    def add(self, triple: Tuple[Node, Node, Node]):
        """Add a triple with self as context"""
        s, p, o = triple
        assert isinstance(s, Node), "Subject %s must be an rdflib term" % (s,)
        assert isinstance(p, Node), "Predicate %s must be an rdflib term" % (p,)
>       assert isinstance(o, Node), "Object %s must be an rdflib term" % (o,)
E       AssertionError: Object None must be an rdflib term

rdflib/graph.py:428: AssertionError
___________________________________________________________________ TypeCheckCase.testPredicateTypeCheck ____________________________________________________________________

self = <test.type_check.TypeCheckCase testMethod=testPredicateTypeCheck>

    def testPredicateTypeCheck(self):
>       self.assertRaises(PredicateTypeError, self.store.add, (foo, None, foo))

test/type_check.py:30: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

    def add(self, triple: Tuple[Node, Node, Node]):
        """Add a triple with self as context"""
        s, p, o = triple
        assert isinstance(s, Node), "Subject %s must be an rdflib term" % (s,)
>       assert isinstance(p, Node), "Predicate %s must be an rdflib term" % (p,)
E       AssertionError: Predicate None must be an rdflib term

rdflib/graph.py:427: AssertionError
____________________________________________________________________ TypeCheckCase.testSubjectTypeCheck _____________________________________________________________________

self = <test.type_check.TypeCheckCase testMethod=testSubjectTypeCheck>

    def testSubjectTypeCheck(self):
>       self.assertRaises(SubjectTypeError, self.store.add, (None, foo, foo))

test/type_check.py:27: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

    def add(self, triple: Tuple[Node, Node, Node]):
        """Add a triple with self as context"""
        s, p, o = triple
>       assert isinstance(s, Node), "Subject %s must be an rdflib term" % (s,)
E       AssertionError: Subject None must be an rdflib term

rdflib/graph.py:426: AssertionError
========================================================================== short test summary info ==========================================================================
FAILED test/type_check.py::TypeCheckCase::testObjectTypeCheck - AssertionError: Object None must be an rdflib term
FAILED test/type_check.py::TypeCheckCase::testPredicateTypeCheck - AssertionError: Predicate None must be an rdflib term
FAILED test/type_check.py::TypeCheckCase::testSubjectTypeCheck - AssertionError: Subject None must be an rdflib term
============================================================================= 3 failed in 0.16s =============================================================================