Attempt to make the test suite pass under mypy 1.0.0

setup.cfg

@@ -27,7 +27,7 @@ packages =
     zope-stubs
 package_dir = =src
 install_requires =
-    mypy==0.981
+    mypy==1.0.0
     zope.interface
     zope.schema
 include_package_data = True

src/mypy_zope/plugin.py

@@ -96,6 +96,9 @@ def make_simple_type(
 }
 
 
+HACK_IS_ABSTRACT_NON_PROPAGATING = -12345678
+
+
 class ZopeInterfacePlugin(Plugin):
     def __init__(self, options: Options):
         super().__init__(options)
@@ -479,6 +482,9 @@ def _analyze_zope_interface(
                 replacement = self._adjust_interface_function(api, cls.info, item)
             elif isinstance(item, OverloadedFuncDef):
                 replacement = self._adjust_interface_overload(api, cls.info, item)
+            elif isinstance(item, Decorator):
+                replacement = item
+                replacement.func = self._adjust_interface_function(api, cls.info, item.func)
             else:
                 continue
 
@@ -520,6 +526,27 @@ def _adjust_interface_function(
             func_def.arg_kinds.insert(0, ARG_POS)
             func_def.arguments.insert(0, selfarg)
 
+        # 1: We want mypy to consider this method abstract, so that it allows the
+        #    method to have an empty body without causing a warning.
+        # 2: We want mypy to consider the interface class NOT abstract, so we can use the
+        #   "adaption" pattern.
+        # Unfortunately whenever mypy sees (1) it will mark the class as abstract,
+        # forcing (2) to be false. This seems to be a change in mypy 0.990, namely
+        #    https://github.com/python/mypy/pull/13729
+        #
+        # Mypy 1.0.0:
+        # - allows empty bodies for abstract methods in mypy/checker.py:1240
+        #   by testing if
+        #       abstract_status != NOT_ABSTRACT.
+        # - marks classes as abstract based on their methods in
+        #   mypy/semanal_classprop.py:79 by testing if
+        #       abstract_status in (IS_ABSTRACT, IMPLICITLY_ABSTRACT)
+        #
+        # Thus we can make (1) and (2) true by setting abstract_status to some value
+        # distinct from these three NOT_ABSTRACT, IS_ABSTRACT and IMPLICITLY_ABSTRACT.
+        # These are presently the integers 0, 1, and 2 defined in mypy/nodes.py:738-743.
+        func_def.abstract_status = HACK_IS_ABSTRACT_NON_PROPAGATING
+
         return func_def
 
     def _adjust_interface_overload(

tests/samples/contextmanager.py

@@ -9,7 +9,7 @@ class A(Generic[_T]):
 
 @contextmanager
 def m(x: _T) -> Iterator[A[_T]]:
-    ...
+    return iter([A()])
 
 
 with m(7) as x:

tests/samples/interface_unknown_inherit.py

@@ -20,7 +20,7 @@ class Bookmark(object):
 <output>
 interface_unknown_inherit.py:8: error: Cannot find implementation or library stub for module named "unknown.interfaces"
 interface_unknown_inherit.py:8: note: See https://mypy.readthedocs.io/en/stable/running_mypy.html#missing-imports
-interface_unknown_inherit.py:11: error: Method must have at least one argument
+interface_unknown_inherit.py:11: error: Method must have at least one argument. Did you forget the "self" argument?
 interface_unknown_inherit.py:14: error: zope.interface.implementer accepts interface, not __main__.IKnownInterface.
 interface_unknown_inherit.py:14: error: Make sure you have stubs for all packages that provide interfaces for __main__.IKnownInterface class hierarchy.
 </output>

tests/samples/overload_readme.py

@@ -14,7 +14,7 @@ def say() -> str:
     def say(count: int) -> List[str]:
         ...
 
-    def say(count: int = None) -> Union[str, List[str]]:
+    def say(count: Optional[int] = None) -> Union[str, List[str]]:
         pass
 
 
@@ -28,7 +28,7 @@ def say(self) -> str:
     def say(self, count: int) -> List[str]:
         ...
 
-    def say(self, count: int = None) -> Union[str, List[str]]:
+    def say(self, count: Optional[int] = None) -> Union[str, List[str]]:
         if count is None:
             return "Mooo"
         return ["Mooo"] * count

tests/test_samples.py

@@ -25,6 +25,7 @@ def test_samples(samplefile, mypy_cache_dir):
     opts.cache_dir = mypy_cache_dir
     opts.show_traceback = True
     opts.namespace_packages = True
+    opts.hide_error_codes = True
     opts.plugins = ['mypy_zope:plugin']
     # Config file is needed to load plugins, it doesn't not exist and is not
     # supposed to.