From d31d09d7cdea45f107f284c755c31d48d3bdca45 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Dani=C3=ABl=20van=20Noord?=
 <13665637+DanielNoord@users.noreply.github.com>
Date: Tue, 6 Feb 2024 01:33:22 +0100
Subject: [PATCH] Add ``--preview`` to instruction for running newly added
 tests (#9846)

## Summary

This surprised me while working on adding a test. I thought about adding
an additional `note`, but how often is this incorrect? In general,
people reading the contributing guidelines probably want to enable this
flag and those who don't will know enough about the testing setup to
have their own commands/aliases.

## Test Plan

Ran CI on local fork and got an all green.
---
 CONTRIBUTING.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 865bb6dc5c..3cd904bc11 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -231,7 +231,7 @@ Once you've completed the code for the rule itself, you can define tests with th
     For example, if you're adding a new rule named `E402`, you would run:
 
     ```shell
-    cargo run -p ruff -- check crates/ruff_linter/resources/test/fixtures/pycodestyle/E402.py --no-cache --select E402
+    cargo run -p ruff -- check crates/ruff_linter/resources/test/fixtures/pycodestyle/E402.py --no-cache --preview --select E402
     ```
 
     **Note:** Only a subset of rules are enabled by default. When testing a new rule, ensure that