test: Add trybuild tests for codegen visibility

actix-web-codegen/tests/trybuild.rs

@@ -6,6 +6,9 @@ fn compile_macros() {
     t.pass("tests/trybuild/simple.rs");
     t.compile_fail("tests/trybuild/simple-fail.rs");
 
+    t.pass("tests/trybuild/visibility-ok.rs");
+    t.compile_fail("tests/trybuild/visibility-fail.rs");
+
     t.pass("tests/trybuild/route-ok.rs");
     t.compile_fail("tests/trybuild/route-missing-method-fail.rs");
     t.compile_fail("tests/trybuild/route-duplicate-method-fail.rs");

actix-web-codegen/tests/trybuild/visibility-fail.rs

@@ -0,0 +1,20 @@
+use actix_web::App;
+
+mod config {
+    use actix_web_codegen::*;
+    use actix_web::{Responder, HttpResponse};
+    
+    #[get("/config")]
+    async fn config() -> impl Responder {
+        HttpResponse::Ok()
+    }
+}
+
+#[actix_web::main]
+async fn main() {
+    let srv = actix_test::start(|| App::new().service(config::config));
+
+    let request = srv.get("/config");
+    let response = request.send().await.unwrap();
+    assert!(response.status().is_success());
+}

actix-web-codegen/tests/trybuild/visibility-fail.stderr

@@ -0,0 +1,12 @@
+error[E0603]: unit struct `config` is private
+  --> tests/trybuild/visibility-fail.rs:15:63
+   |
+15 |     let srv = actix_test::start(|| App::new().service(config::config));
+   |                                                               ^^^^^^ private unit struct
+   |
+note: the unit struct `config` is defined here
+  --> tests/trybuild/visibility-fail.rs:7:5
+   |
+7  |     #[get("/config")]
+   |     ^^^^^^^^^^^^^^^^^
+   = note: this error originates in the attribute macro `get` (in Nightly builds, run with -Z macro-backtrace for more info)

actix-web-codegen/tests/trybuild/visibility-ok.rs

@@ -0,0 +1,20 @@
+use actix_web::App;
+
+mod config {
+    use actix_web_codegen::*;
+    use actix_web::{Responder, HttpResponse};
+
+    #[get("/config")]
+    pub async fn config() -> impl Responder {
+        HttpResponse::Ok()
+    }
+}
+
+#[actix_web::main]
+async fn main() {
+    let srv = actix_test::start(|| App::new().service(config::config));
+
+    let request = srv.get("/config");
+    let response = request.send().await.unwrap();
+    assert!(response.status().is_success());
+}