Add tests that the class attribute is properly updated

IPython/extensions/tests/test_autoreload.py

@@ -39,7 +39,7 b' class FakeShell:'
 
     def __init__(self):
         self.ns = {}
-        self.user_ns = {}
+        self.user_ns = self.ns
         self.user_ns_hidden = {}
         self.events = EventManager(self, {'pre_run_cell', pre_run_cell})
         self.auto_magics = AutoreloadMagics(shell=self)
@@ -49,7 +49,7 b' class FakeShell:'
 
     def run_code(self, code):
         self.events.trigger('pre_run_cell')
-        exec(code, self.ns)
+        exec(code, self.user_ns)
         self.auto_magics.post_execute_hook()
 
     def push(self, items):
@@ -106,7 +106,7 b' class Fixture(object):'
         (because that is stored in the file).  The only reliable way
         to achieve this seems to be to sleep.
         """
-
+        content = textwrap.dedent(content)
         # Sleep one second + eps
         time.sleep(1.05)
 
@@ -115,6 +115,7 b' class Fixture(object):'
             f.write(content)
 
     def new_module(self, code):
+        code = textwrap.dedent(code)
         mod_name, mod_fn = self.get_module()
         with open(mod_fn, 'w') as f:
             f.write(code)
@@ -124,6 +125,17 b' class Fixture(object):'
 # Test automatic reloading
 #-----------------------------------------------------------------------------
 
+def pickle_get_current_class(obj):
+    """
+    Original issue comes from pickle; hence the name.
+    """
+    name = obj.__class__.__name__
+    module_name = getattr(obj, "__module__", None)
+    obj2 = sys.modules[module_name]
+    for subpath in name.split("."):
+        obj2 = getattr(obj2, subpath)
+    return obj2
+
 class TestAutoreload(Fixture):
 
     @skipif(sys.version_info < (3, 6))
@@ -147,6 +159,42 b' class TestAutoreload(Fixture):'
         with tt.AssertNotPrints(('[autoreload of %s failed:' % mod_name), channel='stderr'):
             self.shell.run_code("pass")  # trigger another reload
 
+    def test_reload_class_type(self):
+        self.shell.magic_autoreload("2")
+        mod_name, mod_fn = self.new_module(
+            """
+            class Test():
+                def meth(self):
+                    return "old"
+        """
+        )
+        assert "test" not in self.shell.ns
+        assert "result" not in self.shell.ns
+
+        self.shell.run_code("from %s import Test" % mod_name)
+        self.shell.run_code("test = Test()")
+
+        self.write_file(
+            mod_fn,
+            """
+            class Test():
+                def meth(self):
+                    return "new"
+        """,
+        )
+
+        test_object = self.shell.ns["test"]
+
+        # important to trigger autoreload logic !
+        self.shell.run_code("pass")
+
+        test_class = pickle_get_current_class(test_object)
+        assert isinstance(test_object, test_class)
+
+        # extra check.
+        self.shell.run_code("import pickle")
+        self.shell.run_code("p = pickle.dumps(test)")
+
     def test_reload_class_attributes(self):
         self.shell.magic_autoreload("2")
         mod_name, mod_fn = self.new_module(textwrap.dedent("""
@@ -398,3 +446,4 b' x = -99'
 
 
 
+