From 931a40edab26206d1651ffd3eabeb42264fd964b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20M=C3=BCller?= <deso@posteo.net>
Date: Sun, 5 Jan 2025 13:28:36 -0800
Subject: [PATCH] subscriber: document Subscriber::with_test_writer()
 limitations

Subscriber::with_test_writer() doesn't compose with any earlier calls of
Subscriber::with_writer(), as one would perhaps hope. Rather, both just
overwrite the same member.
Make sure to add a note of this behavior to make it a bit more obvious.
---
 tracing-subscriber/src/fmt/fmt_subscriber.rs | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/tracing-subscriber/src/fmt/fmt_subscriber.rs b/tracing-subscriber/src/fmt/fmt_subscriber.rs
index eec4c3241..605499af1 100644
--- a/tracing-subscriber/src/fmt/fmt_subscriber.rs
+++ b/tracing-subscriber/src/fmt/fmt_subscriber.rs
@@ -266,6 +266,10 @@ impl<C, N, E, W> Subscriber<C, N, E, W> {
     ///
     /// See [`TestWriter`] for additional details.
     ///
+    /// # Notes
+    /// Usage of this method is will overwrite the result of a previous [`with_writer`] invocation;
+    /// the two do not compose.
+    ///
     /// # Examples
     ///
     /// Using [`TestWriter`] to let `cargo test` capture test output: