fix nested self (#382)

docs/changelog.md

@@ -2,6 +2,8 @@
 
 ## Unreleased
 
+- Fix incorrect inference of `self` argument on
+  some nested methods (#382)
 - Fix compatibility between `Callable` and `Annotated`
   (#381)
 - Fix inference for nested `async def` functions (#380)

pyanalyze/name_check_visitor.py

@@ -1553,8 +1553,11 @@ def visit_FunctionDef(
         info = compute_function_info(
             node,
             self,
+            # If we set the current_class in the collecting phase,
+            # the self argument of nested methods with an unannotated
+            # first argument is incorrectly inferred.
             enclosing_class=TypedValue(self.current_class)
-            if self.current_class is not None
+            if self.current_class is not None and self._is_checking()
             else None,
             is_nested_in_class=self.node_context.includes(ast.ClassDef),
             potential_function=potential_function,

pyanalyze/test_functions.py

@@ -82,6 +82,18 @@ def inner():
             inner.punare = 3
             assert_is_value(inner.punare, KnownValue(3))
 
+    @assert_passes()
+    def test_nested_in_method(self):
+        class Capybara:
+            def method(self):
+                def nested(arg) -> int:
+                    assert_is_value(arg, AnyValue(AnySource.unannotated))
+                    # Make sure we don't think this is an access to Capybara.numerator
+                    print(arg.numerator)
+                    return 1
+
+                assert_is_value(nested(1), TypedValue(int))
+
 
 class TestFunctionDefinitions(TestNameCheckVisitorBase):
     @assert_passes()