From b05a5c6dfe09f2bca56f8c2bdb4a631104d064b3 Mon Sep 17 00:00:00 2001
From: David Pedersen <david.pdrsn@gmail.com>
Date: Sun, 6 Mar 2022 17:01:14 +0100
Subject: [PATCH] Make it more obvious that `NEST_TAIL_PARAM` is reserved
 (#836)

---
 axum/src/routing/mod.rs       |  4 ++--
 axum/src/routing/tests/mod.rs | 10 ++++++++--
 2 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/axum/src/routing/mod.rs b/axum/src/routing/mod.rs
index be96a644..d80a3fd1 100644
--- a/axum/src/routing/mod.rs
+++ b/axum/src/routing/mod.rs
@@ -99,8 +99,8 @@ impl<B> fmt::Debug for Router<B> {
     }
 }
 
-pub(crate) const NEST_TAIL_PARAM: &str = "axum_nest";
-const NEST_TAIL_PARAM_CAPTURE: &str = "/*axum_nest";
+pub(crate) const NEST_TAIL_PARAM: &str = "__private__axum_nest_tail_param";
+const NEST_TAIL_PARAM_CAPTURE: &str = "/*__private__axum_nest_tail_param";
 
 impl<B> Router<B>
 where
diff --git a/axum/src/routing/tests/mod.rs b/axum/src/routing/tests/mod.rs
index 4dce4073..4052c653 100644
--- a/axum/src/routing/tests/mod.rs
+++ b/axum/src/routing/tests/mod.rs
@@ -525,7 +525,10 @@ async fn route_layer() {
 
 #[tokio::test]
 #[should_panic(
-    expected = "Invalid route: insertion failed due to conflict with previously registered route: /*axum_nest. Note that `nest(\"/\", _)` conflicts with all routes. Use `Router::fallback` instead"
+    expected = "Invalid route: insertion failed due to conflict with previously registered \
+    route: /*__private__axum_nest_tail_param. \
+    Note that `nest(\"/\", _)` conflicts with all routes. \
+    Use `Router::fallback` instead"
 )]
 async fn good_error_message_if_using_nest_root() {
     let app = Router::new()
@@ -536,7 +539,10 @@ async fn good_error_message_if_using_nest_root() {
 
 #[tokio::test]
 #[should_panic(
-    expected = "Invalid route: insertion failed due to conflict with previously registered route: /*axum_nest. Note that `nest(\"/\", _)` conflicts with all routes. Use `Router::fallback` instead"
+    expected = "Invalid route: insertion failed due to conflict with previously registered \
+    route: /*__private__axum_nest_tail_param. \
+    Note that `nest(\"/\", _)` conflicts with all routes. \
+    Use `Router::fallback` instead"
 )]
 async fn good_error_message_if_using_nest_root_when_merging() {
     let one = Router::new().nest("/", get(|| async {}));