error on missing methods

actix-web-codegen/src/route.rs

@@ -427,23 +427,31 @@ pub(crate) fn with_methods(input: TokenStream) -> TokenStream {
 
     ast.attrs = others.into_iter().map(Result::unwrap_err).collect();
 
-    let methods = match methods
+    let methods =
-        .into_iter()
+        match methods
-        .map(Result::unwrap)
+            .into_iter()
-        .map(|(method, attr)| {
+            .map(Result::unwrap)
-            attr.parse_meta().and_then(|args| {
+            .map(|(method, attr)| {
-                if let Meta::List(args) = args {
+                attr.parse_meta().and_then(|args| {
-                    Args::new(args.nested.into_iter().collect(), Some(method))
+                    if let Meta::List(args) = args {
-                } else {
+                        Args::new(args.nested.into_iter().collect(), Some(method))
-                    Err(syn::Error::new_spanned(attr, "Invalid input for macro"))
+                    } else {
-                }
+                        Err(syn::Error::new_spanned(attr, "Invalid input for macro"))
+                    }
+                })
             })
-        })
+            .collect::<Result<Vec<_>, _>>()
-        .collect()
+        {
-    {
+            Ok(methods) if methods.is_empty() => return input_and_compile_error(
-        Ok(methods) => methods,
+                input,
-        Err(err) => return input_and_compile_error(input, err),
+                syn::Error::new(
-    };
+                    Span::call_site(),
+                    "The #[routes] macro requires at least one `#[<method>(..)]` attribute.",
+                ),
+            ),
+            Ok(methods) => methods,
+            Err(err) => return input_and_compile_error(input, err),
+        };
 
     match Route::multiple(methods, ast) {
         Ok(route) => route.into_token_stream().into(),

actix-web-codegen/tests/trybuild.rs

@@ -13,6 +13,7 @@ fn compile_macros() {
     t.compile_fail("tests/trybuild/route-malformed-path-fail.rs");
 
     t.pass("tests/trybuild/routes-ok.rs");
+    t.compile_fail("tests/trybuild/routes-missing-method-fail.rs");
 
     t.pass("tests/trybuild/docstring-ok.rs");
 

actix-web-codegen/tests/trybuild/routes-missing-method-fail.rs

@@ -0,0 +1,13 @@
+use actix_web_codegen::*;
+
+#[routes]
+async fn index() -> String {
+    "Hello World!".to_owned()
+}
+
+#[actix_web::main]
+async fn main() {
+    use actix_web::App;
+
+    let srv = actix_test::start(|| App::new().service(index));
+}

actix-web-codegen/tests/trybuild/routes-missing-method-fail.stderr

@@ -0,0 +1,13 @@
+error: The #[routes] macro requires at least one `#[<method>(..)]` attribute.
+ --> tests/trybuild/routes-missing-method-fail.rs:3:1
+  |
+3 | #[routes]
+  | ^^^^^^^^^
+  |
+  = note: this error originates in the attribute macro `routes` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error[E0277]: the trait bound `fn() -> impl std::future::Future {index}: HttpServiceFactory` is not satisfied
+  --> tests/trybuild/routes-missing-method-fail.rs:12:55
+   |
+12 |     let srv = actix_test::start(|| App::new().service(index));
+   |                                                       ^^^^^ the trait `HttpServiceFactory` is not implemented for `fn() -> impl std::future::Future {index}`