[flake8-logging] Allow closures in except handlers for LOG004 (#24464)

## Summary

Fixes #18646. 

`outside_handlers` walks AST ancestors looking for a `Try` statement
whose handler range contains the call offset. It used to bail out at
`FunctionDef` nodes to avoid crossing scope boundaries, which meant any
`logging.exception()` inside a closure defined in an except block got
flagged.
                                                            
The range check applies to where the function is defined, not where it's
called (which Ruff can't track). This means functions defined inside an
except block but called outside of it won't be flagged. This tradeoff
fixes the more common false positive at the cost of a less common false
negative.
                                                            
Dropped the `FunctionDef` break.

## Test Plan

- Updated fixture to move function-inside-except to no-errors section
- Added closure-called-within-except test case
- local ecosystem runs showed expected results

---------

Co-authored-by: Charlie Marsh <charlie.r.marsh@gmail.com>

Author: anishgirianish

crates/ruff_linter/resources/test/fixtures/flake8_logging/LOG004_0.py

@@ -21,6 +21,17 @@ def _():
     exc("")
 
 
+### No errors
+
+try:
+    ...
+except ...:
+    logging.exception("")
+    logger.exception("")
+    exc("")
+
+
+# Closures defined in except handlers have access to exc_info
 try:
     ...
 except ...:
@@ -30,14 +41,12 @@ def _():
         exc("")
 
 
-### No errors
-
 try:
     ...
 except ...:
-    logging.exception("")
-    logger.exception("")
-    exc("")
+    def on_failure():
+        logging.exception("closure called within except")
+    on_failure()
 
 
 def _():

crates/ruff_linter/src/rules/flake8_logging/helpers.rs

@@ -4,10 +4,6 @@ use ruff_text_size::{Ranged, TextSize};
 
 pub(super) fn outside_handlers(offset: TextSize, semantic: &SemanticModel) -> bool {
     for stmt in semantic.current_statements() {
-        if matches!(stmt, Stmt::FunctionDef(_)) {
-            break;
-        }
-
         let Stmt::Try(StmtTry { handlers, .. }) = stmt else {
             continue;
         };

crates/ruff_linter/src/rules/flake8_logging/rules/exc_info_outside_except_handler.rs

@@ -41,6 +41,27 @@ use crate::{Fix, FixAvailability, Violation};
 /// logging.warning("Foobar")
 /// ```
 ///
+/// ## Known limitations
+/// This rule checks whether a call is _defined_ inside an exception handler, not
+/// whether it _executes_ inside one. A function defined in an `except` block but
+/// called outside of it will not be flagged, despite the fact that the call may
+/// not have access to an active exception at runtime:
+///
+/// ```python
+/// import logging
+///
+///
+/// try:
+///     raise ValueError()
+/// except Exception:
+///
+///     def handler():
+///         logging.error("Foobar", exc_info=True)  # LOG014 not raised (false negative)
+///
+///
+/// handler()
+/// ```
+///
 /// ## Fix safety
 /// The fix is always marked as unsafe, as it changes runtime behavior.
 ///

crates/ruff_linter/src/rules/flake8_logging/rules/log_exception_outside_except_handler.rs

@@ -39,6 +39,27 @@ use crate::{Edit, Fix, FixAvailability, Violation};
 /// logging.error("Foobar")
 /// ```
 ///
+/// ## Known limitations
+/// This rule checks whether a call is _defined_ inside an exception handler, not
+/// whether it _executes_ inside one. A function defined in an `except` block but
+/// called outside of it will not be flagged, despite the fact that the call may
+/// not have access to an active exception at runtime:
+///
+/// ```python
+/// import logging
+///
+///
+/// try:
+///     raise ValueError()
+/// except Exception:
+///
+///     def handler():
+///         logging.exception("Foobar")  # LOG004 not raised (false negative)
+///
+///
+/// handler()
+/// ```
+///
 /// ## Fix safety
 /// The fix, if available, will always be marked as unsafe, as it changes runtime behavior.
 ///

crates/ruff_linter/src/rules/flake8_logging/snapshots/ruff_linter__rules__flake8_logging__tests__LOG004_LOG004_0.py.snap

@@ -100,54 +100,3 @@ LOG004 `.exception()` call outside exception handlers
    |     ^^^^^^^
    |
 help: Replace with `.error()`
-
-LOG004 [*] `.exception()` call outside exception handlers
-  --> LOG004_0.py:28:9
-   |
-26 | except ...:
-27 |     def _():
-28 |         logging.exception("")
-   |         ^^^^^^^^^^^^^^^^^^^^^
-29 |         logger.exception("")
-30 |         exc("")
-   |
-help: Replace with `.error()`
-25 |     ...
-26 | except ...:
-27 |     def _():
-   -         logging.exception("")
-28 +         logging.error("")
-29 |         logger.exception("")
-30 |         exc("")
-31 |
-note: This is an unsafe fix and may change runtime behavior
-
-LOG004 [*] `.exception()` call outside exception handlers
-  --> LOG004_0.py:29:9
-   |
-27 |     def _():
-28 |         logging.exception("")
-29 |         logger.exception("")
-   |         ^^^^^^^^^^^^^^^^^^^^
-30 |         exc("")
-   |
-help: Replace with `.error()`
-26 | except ...:
-27 |     def _():
-28 |         logging.exception("")
-   -         logger.exception("")
-29 +         logger.error("")
-30 |         exc("")
-31 |
-32 |
-note: This is an unsafe fix and may change runtime behavior
-
-LOG004 `.exception()` call outside exception handlers
-  --> LOG004_0.py:30:9
-   |
-28 |         logging.exception("")
-29 |         logger.exception("")
-30 |         exc("")
-   |         ^^^^^^^
-   |
-help: Replace with `.error()`

crates/ruff_linter/src/rules/flake8_logging/snapshots/ruff_linter__rules__flake8_logging__tests__LOG014_LOG014_0.py.snap

@@ -112,42 +112,3 @@ help: Remove `exc_info=`
 24 |
 25 | try:
 note: This is an unsafe fix and may change runtime behavior
-
-LOG014 [*] `exc_info=` outside exception handlers
-  --> LOG014_0.py:29:26
-   |
-27 | except ...:
-28 |     def _():
-29 |         logging.info("", exc_info=True)
-   |                          ^^^^^^^^^^^^^
-30 |         logger.info("", exc_info=True)
-   |
-help: Remove `exc_info=`
-26 |     ...
-27 | except ...:
-28 |     def _():
-   -         logging.info("", exc_info=True)
-29 +         logging.info("")
-30 |         logger.info("", exc_info=True)
-31 |
-32 |
-note: This is an unsafe fix and may change runtime behavior
-
-LOG014 [*] `exc_info=` outside exception handlers
-  --> LOG014_0.py:30:25
-   |
-28 |     def _():
-29 |         logging.info("", exc_info=True)
-30 |         logger.info("", exc_info=True)
-   |                         ^^^^^^^^^^^^^
-   |
-help: Remove `exc_info=`
-27 | except ...:
-28 |     def _():
-29 |         logging.info("", exc_info=True)
-   -         logger.info("", exc_info=True)
-30 +         logger.info("")
-31 |
-32 |
-33 | ### No errors
-note: This is an unsafe fix and may change runtime behavior