Testing on rustbiteshttps://www.rustbites.com/tags/testing/Recent content in Testing on rustbitesHugoenSat, 30 May 2026 18:44:06 +0200172. #[track_caller] — Point the Panic at the Caller, Not Your Helperhttps://www.rustbites.com/posts/bite-172/Sat, 30 May 2026 17:00:00 +0100https://www.rustbites.com/posts/bite-172/<p>You wrap an <code>assert</code> in a helper to clean up your tests. Now every failure points at the helper&rsquo;s source line instead of the test that called it. <code>#[track_caller]</code> fixes that with a single line of code.</p>171. assert_matches! — A Test Failure That Actually Tells You What Went Wronghttps://www.rustbites.com/posts/bite-171/Sat, 30 May 2026 09:00:00 +0100https://www.rustbites.com/posts/bite-171/<p><code>assert!(matches!(x, Foo::Bar))</code> panics with <code>assertion failed: matches!(x, Foo::Bar)</code> and zero hint about what <code>x</code> actually was. Rust 1.96 stabilises <code>assert_matches!</code>, which prints the offending value for you.</p>