Handle deferred evaluation of annotations in Python 3.14

Author: cdce8p

doc/whatsnew/fragments/10149.feature

@@ -0,0 +1,3 @@
+Handle deferred evaluation of annotations in Python 3.14.
+
+Closes #10149

pylint/checkers/typecheck.py

@@ -976,8 +976,15 @@ class TypeChecker(BaseChecker):
     def open(self) -> None:
         py_version = self.linter.config.py_version
         self._py310_plus = py_version >= (3, 10)
+        self._py314_plus = py_version >= (3, 14)
+        self._postponed_evaluation_enabled = False
         self._mixin_class_rgx = self.linter.config.mixin_class_rgx
 
+    def visit_module(self, node: nodes.Module) -> None:
+        self._postponed_evaluation_enabled = (
+            self._py314_plus or is_postponed_evaluation_enabled(node)
+        )
+
     @cached_property
     def _compiled_generated_members(self) -> tuple[Pattern[str], ...]:
         # do this lazily since config not fully initialized in __init__
@@ -1066,7 +1073,7 @@ def visit_attribute(
         ):
             return
 
-        if is_postponed_evaluation_enabled(node) and is_node_in_type_annotation_context(
+        if self._postponed_evaluation_enabled and is_node_in_type_annotation_context(
             node
         ):
             return
@@ -1950,9 +1957,10 @@ def _detect_unsupported_alternative_union_syntax(self, node: nodes.BinOp) -> Non
         if self._py310_plus:  # 310+ supports the new syntax
             return
 
-        if isinstance(
-            node.parent, TYPE_ANNOTATION_NODES_TYPES
-        ) and not is_postponed_evaluation_enabled(node):
+        if (
+            isinstance(node.parent, TYPE_ANNOTATION_NODES_TYPES)
+            and not self._postponed_evaluation_enabled
+        ):
             # Use in type annotations only allowed if
             # postponed evaluation is enabled.
             self._check_unsupported_alternative_union_syntax(node)
@@ -1974,7 +1982,7 @@ def _detect_unsupported_alternative_union_syntax(self, node: nodes.BinOp) -> Non
             # Make sure to filter context if postponed evaluation is enabled
             # and parent is allowed node type.
             allowed_nested_syntax = False
-            if is_postponed_evaluation_enabled(node):
+            if self._postponed_evaluation_enabled:
                 parent_node = node.parent
                 while True:
                     if isinstance(parent_node, TYPE_ANNOTATION_NODES_TYPES):

pylint/checkers/variables.py

@@ -1300,6 +1300,10 @@ def __init__(self, linter: PyLinter) -> None:
         ] = {}
         self._postponed_evaluation_enabled = False
 
+    def open(self) -> None:
+        py_version = self.linter.config.py_version
+        self._py314_plus = py_version >= (3, 14)
+
     @utils.only_required_for_messages(
         "unbalanced-dict-unpacking",
     )
@@ -1363,7 +1367,9 @@ def visit_module(self, node: nodes.Module) -> None:
         checks globals doesn't overrides builtins.
         """
         self._to_consume = [NamesConsumer(node, "module")]
-        self._postponed_evaluation_enabled = is_postponed_evaluation_enabled(node)
+        self._postponed_evaluation_enabled = (
+            self._py314_plus or is_postponed_evaluation_enabled(node)
+        )
 
         for name, stmts in node.locals.items():
             if utils.is_builtin(name):
@@ -2489,8 +2495,8 @@ def _is_only_type_assignment(
             parent = parent_scope.parent
         return True
 
-    @staticmethod
     def _is_first_level_self_reference(
+        self,
         node: nodes.Name,
         defstmt: nodes.ClassDef,
         found_nodes: list[nodes.NodeNG],
@@ -2502,7 +2508,7 @@ def _is_first_level_self_reference(
             # Check if used as type annotation
             # Break if postponed evaluation is enabled
             if utils.is_node_in_type_annotation_context(node):
-                if not utils.is_postponed_evaluation_enabled(node):
+                if not self._postponed_evaluation_enabled:
                     return (VariableVisitConsumerAction.CONTINUE, None)
                 return (VariableVisitConsumerAction.RETURN, None)
             # Check if used as default value by calling the class

pylint/extensions/typing.py

@@ -186,6 +186,8 @@ def open(self) -> None:
         self._py39_plus = py_version >= (3, 9)
         self._py310_plus = py_version >= (3, 10)
         self._py313_plus = py_version >= (3, 13)
+        self._py314_plus = py_version >= (3, 14)
+        self._postponed_evaluation_enabled = False
 
         self._should_check_typing_alias = self._py39_plus or (
             self._py37_plus and self.linter.config.runtime_typing is False
@@ -197,6 +199,11 @@ def open(self) -> None:
         self._should_check_noreturn = py_version < (3, 7, 2)
         self._should_check_callable = py_version < (3, 9, 2)
 
+    def visit_module(self, node: nodes.Module) -> None:
+        self._postponed_evaluation_enabled = (
+            self._py314_plus or is_postponed_evaluation_enabled(node)
+        )
+
     def _msg_postponed_eval_hint(self, node: nodes.NodeNG) -> str:
         """Message hint if postponed evaluation isn't enabled."""
         if self._py310_plus or "annotations" in node.root().future_imports:
@@ -474,7 +481,7 @@ def _check_broken_noreturn(self, node: nodes.Name | nodes.Attribute) -> None:
             return
 
         if in_type_checking_block(node) or (
-            is_postponed_evaluation_enabled(node)
+            self._postponed_evaluation_enabled
             and is_node_in_type_annotation_context(node)
         ):
             return
@@ -511,7 +518,7 @@ def _check_broken_callable(self, node: nodes.Name | nodes.Attribute) -> None:
     def _broken_callable_location(self, node: nodes.Name | nodes.Attribute) -> bool:
         """Check if node would be a broken location for collections.abc.Callable."""
         if in_type_checking_block(node) or (
-            is_postponed_evaluation_enabled(node)
+            self._postponed_evaluation_enabled
             and is_node_in_type_annotation_context(node)
         ):
             return False

pylint/testutils/functional/find_functional_tests.py

@@ -10,7 +10,7 @@
 
 from pylint.testutils.functional.test_file import FunctionalTestFile
 
-REASONABLY_DISPLAYABLE_VERTICALLY = 49
+REASONABLY_DISPLAYABLE_VERTICALLY = 55
 """'Wet finger' number of files that are reasonable to display by an IDE.
 
 'Wet finger' as in 'in my settings there are precisely this many'.

tests/functional/p/postponed/postponed_evaluation_not_activated.rc

@@ -0,0 +1,2 @@
+[testoptions]
+max_pyver=3.14

tests/functional/p/postponed/postponed_evaluation_not_activated_py314.py

@@ -0,0 +1,14 @@
+# pylint: disable=missing-docstring,unused-argument,pointless-statement
+# pylint: disable=too-few-public-methods
+
+class Class:
+    @classmethod
+    def from_string(cls, source) -> Class:
+        ...
+
+    def validate_b(self, obj: OtherClass) -> bool:
+        ...
+
+
+class OtherClass:
+    ...

tests/functional/p/postponed/postponed_evaluation_not_activated_py314.rc

@@ -0,0 +1,2 @@
+[testoptions]
+min_pyver=3.14

tests/functional/u/undefined/undefined_variable_deferred_annotations.py

@@ -0,0 +1,18 @@
+# pylint: disable=missing-docstring
+class Undefined:
+    """ test various annotation problems. """
+
+    def test(self) -> Undefined:  # [undefined-variable]
+        """ used Undefined, which is Undefined in this scope. """
+
+    Undefined = True
+
+    def test1(self) -> Undefined:
+        """ This Undefined exists at local scope. """
+
+    def test2(self):
+        """ This should not emit. """
+        def func() -> Undefined:
+            """ empty """
+            return 2
+        return func

tests/functional/u/undefined/undefined_variable_deferred_annotations.rc

@@ -0,0 +1,2 @@
+[testoptions]
+max_pyver=3.14