diff --git a/openless-all/app/src-tauri/backend-tests/Cargo.toml b/openless-all/app/src-tauri/backend-tests/Cargo.toml
index 8b8b5e47..d3dc05c1 100644
--- a/openless-all/app/src-tauri/backend-tests/Cargo.toml
+++ b/openless-all/app/src-tauri/backend-tests/Cargo.toml
@@ -5,6 +5,10 @@ edition = "2021"
 rust-version = "1.77"
 publish = false
 
+[[test]]
+name = "backend_rust"
+path = "tests/backend_rust.rs"
+
 [dependencies]
 arboard = "3"
 cpal = "0.15"
diff --git a/openless-all/app/src-tauri/backend-tests/tests/backend_rust.rs b/openless-all/app/src-tauri/backend-tests/tests/backend_rust.rs
index 23e75a81..08ef2f2a 100644
--- a/openless-all/app/src-tauri/backend-tests/tests/backend_rust.rs
+++ b/openless-all/app/src-tauri/backend-tests/tests/backend_rust.rs
@@ -2,6 +2,8 @@
 //!
 //! 这个测试 crate 只把纯 Rust 后端模块按源码路径编进来，不链接完整 Tauri
 //! `openless_lib`，避免 Windows CI 在 test harness 启动前被桌面运行时 DLL 拦截。
+//! Cargo 以 `cfg(test)` 编译这些 path-included 模块，所以各模块自己的
+//! `#[cfg(test)]` 单测会在这里实际执行（见 hotkey / recorder / insertion）。
 
 #![allow(dead_code, unused_variables)]