1 files changed, 101 insertions, 3 deletions
diff --git a/tests/run/cyfunction_defaults.pyx b/tests/run/cyfunction_defaults.pyx
index 2fe592a23..e57538952 100644
--- a/tests/run/cyfunction_defaults.pyx
+++ b/tests/run/cyfunction_defaults.pyx
@@ -86,10 +86,49 @@ def test_defaults_nonliteral_func_call(f):
         return a
     return func
 
+def assign_defaults_and_check_warnings(func, value=None, delete=False):
+    import warnings
+    with warnings.catch_warnings(record=True) as w:
+        warnings.simplefilter("always")
+        if delete:
+            del func.__defaults__
+        else:
+            func.__defaults__ = value
+        assert len(w) == 1, len(w)
+        assert issubclass(w[0].category, RuntimeWarning), w[0].category
+        assert "changes to cyfunction.__defaults__" in str(w[0].message), str(w[0].message)
+
+def test_assign_defaults():
+    """
+    >>> f = test_assign_defaults()
+    >>> f.__defaults__
+    (5, 10)
+    >>> assign_defaults_and_check_warnings(f, value=())
+    >>> f.__defaults__
+    ()
+    >>> assign_defaults_and_check_warnings(f, delete=True)
+    >>> f.__defaults__
+    >>> f.__defaults__ = "Not a tuple"
+    Traceback (most recent call last):
+    TypeError: __defaults__ must be set to a tuple object
+    """
+    def func(a=5, b=10):
+        return a, b
+    return func
+
 
 def cy_kwonly_default_args(a, x=1, *, b=2):
     l = m = 1
 
+def assign_kwdefaults_and_check_warnings(func, value):
+    import warnings
+    with warnings.catch_warnings(record=True) as w:
+        warnings.simplefilter("always")
+        func.__kwdefaults__ = value
+        assert len(w) == 1, len(w)
+        assert issubclass(w[0].category, RuntimeWarning), w[0].category
+        assert "changes to cyfunction.__kwdefaults__" in str(w[0].message), str(w[0].message)
+
 def test_kwdefaults(value):
     """
     >>> cy_kwonly_default_args.__defaults__
@@ -111,12 +150,12 @@ def test_kwdefaults(value):
     >>> f.__kwdefaults__ = ()
     Traceback (most recent call last):
     TypeError: __kwdefaults__ must be set to a dict object
-    >>> f.__kwdefaults__ = None
+    >>> assign_kwdefaults_and_check_warnings(f, None)
     >>> f.__kwdefaults__
-    >>> f.__kwdefaults__ = {}
+    >>> assign_kwdefaults_and_check_warnings(f, {})
     >>> f.__kwdefaults__
     {}
-    >>> f.__kwdefaults__ = {'a': 2}
+    >>> assign_kwdefaults_and_check_warnings(f, {'a': 2})
     >>> f.__kwdefaults__
     {'a': 2}
     """
@@ -251,3 +290,62 @@ def test_func_default_scope_local():
         return arg
     print i  # genexprs don't leak
     return func
+
+cdef class C:
+    def f1(self, a, b=1, c=[]):
+        pass
+    def f2(self, a, b=1,/, c=[1]):
+        pass
+    def f3(self, a, /, b=1, *, c=[1]):
+        pass
+    cpdef f4(self, a, char*c=NULL):
+        pass
+    cpdef f5(self, a, str s = "123"):
+        pass
+    cpdef f6(self, a, int s = 4):
+        pass
+    cpdef f7(self, a, dict s = {'a':22}):
+        pass
+    cpdef f8(self, a, list s = [15]):
+        pass
+    cpdef f9(self, a, int[:] s = None):
+        pass
+    def f10(self, a, /, b=1, *, int[:] c=None):
+        pass
+
+
+def check_defaults_on_methods_for_introspection():
+    """
+    >>> C.f1.__defaults__
+    (1, [])
+    >>> C.f1.__kwdefaults__
+    >>> C.f2.__defaults__
+    (1, [1])
+    >>> C.f2.__kwdefaults__
+    >>> C.f3.__defaults__
+    (1,)
+    >>> C.f3.__kwdefaults__
+    {'c': [1]}
+    >>> C.f4.__defaults__
+    >>> C.f4.__kwdefaults__
+    >>> C.f5.__defaults__
+    ('123',)
+    >>> C.f5.__kwdefaults__
+    >>> C.f6.__defaults__
+    (4,)
+    >>> C.f6.__kwdefaults__
+    >>> C.f7.__defaults__
+    ({'a': 22},)
+    >>> C.f7.__kwdefaults__
+    >>> C.f8.__defaults__
+    ([15],)
+    >>> C.f8.__kwdefaults__
+    >>> C.f9.__defaults__
+    (None,)
+    >>> C.f9.__kwdefaults__
+    >>> C.f10.__defaults__
+    (1,)
+    >>> C.f10.__kwdefaults__
+    {'c': None}
+    """
+    pass