Allow pallet::call to return DispatchResult (#8241)

* allow dispatch result

* remove custom error message

* format

* add forgotten UI test

* fix test

* fix tests

substrate/frame/support/test/tests/pallet.rs

@@ -161,6 +161,14 @@ pub mod pallet {
 
 			Ok(().into())
 		}
+
+		// Test for DispatchResult return type
+		#[pallet::weight(1)]
+		fn foo_no_post_info(
+			_origin: OriginFor<T>,
+		) -> DispatchResult {
+			Ok(())
+		}
 	}
 
 	#[pallet::error]
@@ -425,7 +433,7 @@ fn call_expand() {
 	assert_eq!(call_foo.get_call_name(), "foo");
 	assert_eq!(
 		pallet::Call::<Runtime>::get_call_names(),
-		&["foo", "foo_transactional"],
+		&["foo", "foo_transactional", "foo_no_post_info"],
 	);
 }
 
@@ -669,6 +677,11 @@ fn metadata() {
 					" Doc comment put in metadata".to_string(),
 				]),
 			},
+			FunctionMetadata {
+				name: DecodeDifferent::Decoded("foo_no_post_info".to_string()),
+				arguments: DecodeDifferent::Decoded(vec![]),
+				documentation: DecodeDifferent::Decoded(vec![]),
+			},
 		])),
 		event: Some(DecodeDifferent::Decoded(vec![
 			EventMetadata {

substrate/frame/support/test/tests/pallet_ui/call_invalid_return.rs

@@ -0,0 +1,22 @@
+#[frame_support::pallet]
+mod pallet {
+	use frame_support::pallet_prelude::Hooks;
+	use frame_system::pallet_prelude::{BlockNumberFor, OriginFor};
+
+	#[pallet::config]
+	pub trait Config: frame_system::Config {}
+
+	#[pallet::pallet]
+	pub struct Pallet<T>(core::marker::PhantomData<T>);
+
+	#[pallet::hooks]
+	impl<T: Config> Hooks<BlockNumberFor<T>> for Pallet<T> {}
+
+	#[pallet::call]
+	impl<T: Config> Pallet<T> {
+		fn foo(origin: OriginFor<T>) -> ::DispatchResult { todo!() }
+	}
+}
+
+fn main() {
+}

substrate/frame/support/test/tests/pallet_ui/call_invalid_return.stderr

@@ -0,0 +1,5 @@
+error: expected `DispatchResultWithPostInfo` or `DispatchResult`
+  --> $DIR/call_invalid_return.rs:17:35
+   |
+17 |         fn foo(origin: OriginFor<T>) -> ::DispatchResult { todo!() }
+   |                                         ^^