Also check Lambda for await-outside-async (#9653)

Author: UTsweetyfish

doc/whatsnew/fragments/9653.false_negative

@@ -0,0 +1,3 @@
+Fix a false positive for `await-outside-async` when await is inside Lambda.
+
+Refs #9653

pylint/checkers/typecheck.py

@@ -2197,7 +2197,7 @@ def _check_await_outside_coroutine(self, node: nodes.Await) -> None:
         while not isinstance(node_scope, nodes.Module):
             if isinstance(node_scope, nodes.AsyncFunctionDef):
                 return
-            if isinstance(node_scope, nodes.FunctionDef):
+            if isinstance(node_scope, (nodes.FunctionDef, nodes.Lambda)):
                 break
             node_scope = node_scope.parent.scope()
         self.add_message("await-outside-async", node=node)

tests/functional/a/await_outside_async.py

@@ -28,3 +28,7 @@ def inner_func():
 def outer_func():
     async def inner_func():
         await asyncio.sleep(1)
+
+# pylint: disable=unnecessary-lambda-assignment
+async def func3():
+    f = lambda: await nested() # [await-outside-async]

tests/functional/a/await_outside_async.txt

@@ -1,2 +1,3 @@
 await-outside-async:12:10:12:24:not_async:'await' should be used within an async function:UNDEFINED
 await-outside-async:25:8:25:30:func2.inner_func:'await' should be used within an async function:UNDEFINED
+await-outside-async:34:16:34:30:func3.<lambda>:'await' should be used within an async function:UNDEFINED