Add trait to get module and call names. (#4854)

* Add trait to get module and call names.


Co-authored-by: Bastian Köcher <bkchr@users.noreply.github.com>

substrate/frame/support/src/dispatch.rs

@@ -1346,6 +1346,14 @@ macro_rules! decl_module {
 					$call_type::__PhantomItem(_, _) => unreachable!("__PhantomItem should never be used."),
 				}
 			}
+
+			fn get_call_names() -> &'static [&'static str] {
+				&[
+					$(
+						stringify!($fn_name),
+					)*
+				]
+			}
 		}
 
 		// manual implementation of clone/eq/partialeq because using derive erroneously requires
@@ -1518,6 +1526,24 @@ macro_rules! impl_outer_dispatch {
 					}, )*
 				}
 			}
+
+			fn get_module_names() -> &'static [&'static str] {
+				&[$(
+					stringify!($camelcase),
+				)*]
+			}
+
+			fn get_call_names(module: &str) -> &'static [&'static str] {
+				use $crate::dispatch::{Callable, GetCallName};
+				match module {
+					$(
+						stringify!($camelcase) =>
+							<<$camelcase as Callable<$runtime>>::Call
+								as GetCallName>::get_call_names(),
+					)*
+					_ => unreachable!(),
+				}
+			}
 		}
 		impl $crate::dispatch::Dispatchable for $call_type {
 			type Origin = $origin;
@@ -2118,4 +2144,16 @@ mod tests {
 		let expected = CallMetadata { function_name: "aux_3".into(), pallet_name: "Test".into() };
 		assert_eq!(metadata, expected);
 	}
+
+	#[test]
+	fn get_call_names() {
+		let call_names = Call::<TraitImpl>::get_call_names();
+		assert_eq!(["aux_0", "aux_1", "aux_2", "aux_3", "aux_4", "aux_5", "operational"], call_names);
+	}
+
+	#[test]
+	fn get_module_names() {
+		let module_names = OuterCall::get_module_names();
+		assert_eq!(["Test"], module_names);
+	}
 }

substrate/frame/support/src/traits.rs

@@ -819,12 +819,18 @@ pub struct CallMetadata {
 
 /// Gets the function name of the Call.
 pub trait GetCallName {
+	/// Return all function names.
+	fn get_call_names() -> &'static [&'static str];
 	/// Return the function name of the Call.
 	fn get_call_name(&self) -> &'static str;
 }
 
 /// Gets the metadata for the Call - function name and pallet name.
 pub trait GetCallMetadata {
+	/// Return all module names.
+	fn get_module_names() -> &'static [&'static str];
+	/// Return all function names for the given `module`.
+	fn get_call_names(module: &str) -> &'static [&'static str];
 	/// Return a [`CallMetadata`], containing function and pallet name of the Call.
 	fn get_call_metadata(&self) -> CallMetadata;
 }