From 7f3bd109fc5f3759b4f1d03f3f5e37695507d77b Mon Sep 17 00:00:00 2001
From: Steffen Deusch <steffen@deusch.me>
Date: Thu, 19 Feb 2026 18:36:54 +0100
Subject: [PATCH] Fail when misnamed test files are detected and
 --warnings-as-errors is set

Closes https://github.com/elixir-lang/elixir/issues/15105.
---
 lib/mix/lib/mix/tasks/test.ex | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/lib/mix/lib/mix/tasks/test.ex b/lib/mix/lib/mix/tasks/test.ex
index 7e87a2fba2..e875eaade6 100644
--- a/lib/mix/lib/mix/tasks/test.ex
+++ b/lib/mix/lib/mix/tasks/test.ex
@@ -714,7 +714,8 @@ defmodule Mix.Tasks.Test do
         cover && cover.()
 
         cond do
-          warnings_as_errors? and (warnings? or helper_warned?) and failures == 0 ->
+          warnings_as_errors? and (warnings? or helper_warned? or warn_files != []) and
+              failures == 0 ->
             message =
               "\nERROR! Test suite aborted after successful execution due to warnings while using the --warnings-as-errors option"