Fix #5399: Fix false negative for undefined-variable when a type an…

…notation is accessed multiple times
pylint-dev · Jan 26, 2022 · ba0a8ac · ba0a8ac
1 parent 44ad84a
commit ba0a8ac
Show file tree

Hide file tree

Showing 9 changed files with 43 additions and 21 deletions.
diff --git a/ChangeLog b/ChangeLog
@@ -87,6 +87,12 @@ Release date: TBA
 
   Closes #5568
 
+* Fix false negative for ``undefined-variable`` and related variable messages
+  when the same undefined variable is used as a type annotation and is
+  accessed multiple times, or is used as a default argument to a function.
+
+  Closes #5399
+
 * Pyreverse - add output in mermaidjs format
 
 * Emit ``used-before-assignment`` instead of ``undefined-variable`` when attempting

diff --git a/doc/whatsnew/2.13.rst b/doc/whatsnew/2.13.rst
@@ -124,6 +124,12 @@ Other Changes
   Closes #4798
   Closes #5081
 
+* Fix false negative for ``undefined-variable`` and related variable messages
+  when the same undefined variable is used as a type annotation and is
+  accessed multiple times, or is used as a default argument to a function.
+
+  Closes #5399
+
 * Emit ``used-before-assignment`` instead of ``undefined-variable`` when attempting
   to access unused type annotations.
 

diff --git a/pylint/checkers/variables.py b/pylint/checkers/variables.py
@@ -1528,10 +1528,7 @@ def _check_consumer(
                         )
                         and node.name in node.root().locals
                     ):
-                        self.add_message(
-                            "undefined-variable", args=node.name, node=node
-                        )
-                        return (VariableVisitConsumerAction.CONSUME, found_nodes)
+                        return (VariableVisitConsumerAction.CONTINUE, None)
 
             elif base_scope_type != "lambda":
                 # E0601 may *not* occurs in lambda scope.
@@ -1585,9 +1582,7 @@ def _check_consumer(
         elif isinstance(defstmt, nodes.ClassDef):
             is_first_level_ref = self._is_first_level_self_reference(node, defstmt)
             if is_first_level_ref == 2:
-                self.add_message(
-                    "used-before-assignment", node=node, args=node.name, confidence=HIGH
-                )
+                return (VariableVisitConsumerAction.CONTINUE, None)
             if is_first_level_ref:
                 return (VariableVisitConsumerAction.RETURN, None)
 
@@ -1988,15 +1983,15 @@ def _is_first_level_self_reference(
         refers to its own class.
 
         Return values correspond to:
-            0 = Continue
+            0 = Continue and consume names
             1 = Break
-            2 = Break + emit message
+            2 = Continue without consuming names
         """
         if node.frame(future=True).parent == defstmt and node.statement(
             future=True
         ) == node.frame(future=True):
             # Check if used as type annotation
-            # Break but don't emit message if postponed evaluation is enabled
+            # Break if postponed evaluation is enabled
             if utils.is_node_in_type_annotation_context(node):
                 if not utils.is_postponed_evaluation_enabled(node):
                     return 2

diff --git a/tests/functional/u/undefined/undefined_variable.py b/tests/functional/u/undefined/undefined_variable.py
@@ -28,8 +28,8 @@ def bad_default(var, default=unknown2):  # [undefined-variable]
     """function with default arg's value set to an nonexistent name"""
     print(var, default)
     print(xxxx)  # [undefined-variable]
-    augvar += 1  # [undefined-variable]
-    del vardel  # [undefined-variable]
+    augvar += 1  # [undefined-variable, unused-variable]
+    del vardel  # [undefined-variable, unused-variable]
 
 LMBD = lambda x, y=doesnotexist: x+y  # [undefined-variable]
 LMBD2 = lambda x, y: x+z  # [undefined-variable]
@@ -133,7 +133,7 @@ class Ancestor1(object):
     """ No op """
 
 NANA = BAT # [undefined-variable]
-del BAT
+del BAT  # [undefined-variable]
 
 
 class KeywordArgument(object):
@@ -356,3 +356,12 @@ def global_var_mixed_assignment():
 
 GLOBAL_VAR: int
 GLOBAL_VAR_TWO: int
+
+
+class RepeatedReturnAnnotations:
+    def x(self, o: RepeatedReturnAnnotations) -> bool:  # [undefined-variable]
+        pass
+    def y(self) -> RepeatedReturnAnnotations:  # [undefined-variable]
+        pass
+    def z(self) -> RepeatedReturnAnnotations:  # [undefined-variable]
+        pass
diff --git a/tests/functional/u/undefined/undefined_variable.txt b/tests/functional/u/undefined/undefined_variable.txt
@@ -5,7 +5,9 @@ undefined-variable:23:8:23:20::Undefined variable '__revision__':UNDEFINED
 undefined-variable:27:29:27:37:bad_default:Undefined variable 'unknown2':UNDEFINED
 undefined-variable:30:10:30:14:bad_default:Undefined variable 'xxxx':UNDEFINED
 undefined-variable:31:4:31:10:bad_default:Undefined variable 'augvar':UNDEFINED
+unused-variable:31:4:31:10:bad_default:Unused variable 'augvar':UNDEFINED
 undefined-variable:32:8:32:14:bad_default:Undefined variable 'vardel':UNDEFINED
+unused-variable:32:8:32:14:bad_default:Unused variable 'vardel':UNDEFINED
 undefined-variable:34:19:34:31:<lambda>:Undefined variable 'doesnotexist':UNDEFINED
 undefined-variable:35:23:35:24:<lambda>:Undefined variable 'z':UNDEFINED
 used-before-assignment:38:4:38:9::Using variable 'POUET' before assignment:CONTROL_FLOW
@@ -19,6 +21,7 @@ used-before-assignment:98:26:98:35:TestClass.MissingAncestor:Using variable 'Anc
 used-before-assignment:105:36:105:41:TestClass.test1.UsingBeforeDefinition:Using variable 'Empty' before assignment:HIGH
 undefined-variable:119:10:119:14:Self:Undefined variable 'Self':UNDEFINED
 undefined-variable:135:7:135:10::Undefined variable 'BAT':UNDEFINED
+undefined-variable:136:4:136:7::Undefined variable 'BAT':UNDEFINED
 used-before-assignment:146:31:146:38:KeywordArgument.test1:Using variable 'enabled' before assignment:HIGH
 undefined-variable:149:32:149:40:KeywordArgument.test2:Undefined variable 'disabled':UNDEFINED
 undefined-variable:154:22:154:25:KeywordArgument.<lambda>:Undefined variable 'arg':UNDEFINED
@@ -33,3 +36,6 @@ used-before-assignment:294:7:294:8:undefined_annotation:Using variable 'x' befor
 undefined-variable:324:11:324:12:decorated3:Undefined variable 'x':UNDEFINED
 undefined-variable:329:19:329:20:decorated4:Undefined variable 'y':UNDEFINED
 undefined-variable:350:10:350:20:global_var_mixed_assignment:Undefined variable 'GLOBAL_VAR':HIGH
+undefined-variable:362:19:362:44:RepeatedReturnAnnotations.x:Undefined variable 'RepeatedReturnAnnotations':UNDEFINED
+undefined-variable:364:19:364:44:RepeatedReturnAnnotations.y:Undefined variable 'RepeatedReturnAnnotations':UNDEFINED
+undefined-variable:366:19:366:44:RepeatedReturnAnnotations.z:Undefined variable 'RepeatedReturnAnnotations':UNDEFINED
diff --git a/tests/functional/u/use/used_before_assignment_py37.py b/tests/functional/u/use/used_before_assignment_py37.py
@@ -14,7 +14,7 @@ def second_correct_typing_method(self, other: List[MyClass]) -> bool:
         return self == other[0]
 
     def incorrect_default_method(
-        self, other=MyClass() # [used-before-assignment]
+        self, other=MyClass() # [undefined-variable]
     ) -> bool:
         return self == other
 

diff --git a/tests/functional/u/use/used_before_assignment_py37.txt b/tests/functional/u/use/used_before_assignment_py37.txt
@@ -1 +1 @@
-used-before-assignment:17:20:17:27:MyClass.incorrect_default_method:Using variable 'MyClass' before assignment:HIGH
+undefined-variable:17:20:17:27:MyClass.incorrect_default_method:Undefined variable 'MyClass':UNDEFINED
diff --git a/tests/functional/u/use/used_before_assignment_typing.py b/tests/functional/u/use/used_before_assignment_typing.py
@@ -9,17 +9,17 @@ class MyClass:
     """Type annotation or default values for first level methods can't refer to their own class"""
 
     def incorrect_typing_method(
-        self, other: MyClass  # [used-before-assignment]
+        self, other: MyClass  # [undefined-variable]
     ) -> bool:
         return self == other
 
     def incorrect_nested_typing_method(
-        self, other: List[MyClass]  # [used-before-assignment]
+        self, other: List[MyClass]  # [undefined-variable]
     ) -> bool:
         return self == other[0]
 
     def incorrect_default_method(
-        self, other=MyClass()  # [used-before-assignment]
+        self, other=MyClass()  # [undefined-variable]
     ) -> bool:
         return self == other
 

diff --git a/tests/functional/u/use/used_before_assignment_typing.txt b/tests/functional/u/use/used_before_assignment_typing.txt
@@ -1,3 +1,3 @@
-used-before-assignment:12:21:12:28:MyClass.incorrect_typing_method:Using variable 'MyClass' before assignment:HIGH
-used-before-assignment:17:26:17:33:MyClass.incorrect_nested_typing_method:Using variable 'MyClass' before assignment:HIGH
-used-before-assignment:22:20:22:27:MyClass.incorrect_default_method:Using variable 'MyClass' before assignment:HIGH
+undefined-variable:12:21:12:28:MyClass.incorrect_typing_method:Undefined variable 'MyClass':UNDEFINED
+undefined-variable:17:26:17:33:MyClass.incorrect_nested_typing_method:Undefined variable 'MyClass':UNDEFINED
+undefined-variable:22:20:22:27:MyClass.incorrect_default_method:Undefined variable 'MyClass':UNDEFINED
Original file line number	Diff line number	Diff line change
		@@ -1 +1 @@
		used-before-assignment:17:20:17:27:MyClass.incorrect_default_method:Using variable 'MyClass' before assignment:HIGH
		undefined-variable:17:20:17:27:MyClass.incorrect_default_method:Undefined variable 'MyClass':UNDEFINED