From b3243b5e2aa6b7f15a41af4c61780ed13afa98ae Mon Sep 17 00:00:00 2001
From: Brent Westbrook <36778786+ntBre@users.noreply.github.com>
Date: Fri, 4 Apr 2025 15:13:59 -0400
Subject: [PATCH] Run fuzzer with `--preview` (#17210)

Summary
--

Updates `fuzz.py` to run with `--preview`, which should allow it to
catch semantic syntax errors.

Test Plan
--

@AlexWaygood and I temporarily made any named expression a semantic
syntax error and checked that this led to fuzzing errors. We also tested
that reverting the `--preview` addition did not show any errors.

We also ran the fuzzer on 500 seeds on `main` but didn't find any
issues, (un)fortunately.
---
 python/py-fuzzer/fuzz.py | 1 +
 1 file changed, 1 insertion(+)

diff --git a/python/py-fuzzer/fuzz.py b/python/py-fuzzer/fuzz.py
index 5cbf2b145f..1028ca2d90 100644
--- a/python/py-fuzzer/fuzz.py
+++ b/python/py-fuzzer/fuzz.py
@@ -71,6 +71,7 @@ def ruff_contains_bug(code: str, *, ruff_executable: Path) -> bool:
             "--no-cache",
             "--target-version",
             "py313",
+            "--preview",
             "-",
         ],
         capture_output=True,