Provide simple TestSessionHandler that works with UintAuthorityId (#3962)

substrate/core/primitives/src/crypto.rs

@@ -898,7 +898,6 @@ pub mod key_types {
 	/// Key type for ImOnline module, built-in.
 	pub const IM_ONLINE: KeyTypeId = KeyTypeId(*b"imon");
 	/// A key type ID useful for tests.
-	#[cfg(feature = "std")]
 	pub const DUMMY: KeyTypeId = KeyTypeId(*b"dumy");
 }
 

substrate/srml/session/src/lib.rs

@@ -259,7 +259,7 @@ pub trait OneSessionHandler<ValidatorId>: BoundToRuntimeAppPublic {
 	fn on_disabled(_validator_index: usize);
 }
 
-#[impl_trait_for_tuples::impl_for_tuples(30)]
+#[impl_trait_for_tuples::impl_for_tuples(1, 30)]
 #[tuple_types_no_default_trait_bound]
 impl<AId> SessionHandler<AId> for Tuple {
 	for_tuples!( where #( Tuple: OneSessionHandler<AId> )* );
@@ -307,6 +307,20 @@ impl<AId> SessionHandler<AId> for Tuple {
 	}
 }
 
+/// `SessionHandler` for tests that use `UintAuthorityId` as `Keys`.
+pub struct TestSessionHandler;
+impl<AId> SessionHandler<AId> for TestSessionHandler {
+	const KEY_TYPE_IDS: &'static [KeyTypeId] = &[sr_primitives::key_types::DUMMY];
+
+	fn on_genesis_session<Ks: OpaqueKeys>(_: &[(AId, Ks)]) {}
+
+	fn on_new_session<Ks: OpaqueKeys>(_: bool, _: &[(AId, Ks)], _: &[(AId, Ks)]) {}
+
+	fn on_before_session_ending() {}
+
+	fn on_disabled(_: usize) {}
+}
+
 /// Handler for selecting the genesis validator set.
 pub trait SelectInitialValidators<ValidatorId> {
 	/// Returns the initial validator set. If `None` is returned