test account events and fix some bugs

frame/balances/src/lib.rs

@@ -1230,7 +1230,14 @@ impl<T: Trait<I>, I: Instance> ReservableCurrency<T::AccountId> for Module<T, I>
 /// storage (which is the default in most examples and tests) then there's no need.**
 impl<T: Trait<I>, I: Instance> OnKilledAccount<T::AccountId> for Module<T, I> {
 	fn on_killed_account(who: &T::AccountId) {
-		Account::<T, I>::remove(who);
+		Account::<T, I>::mutate_exists(who, |account| {
+			let total = account.as_ref().map(|acc| acc.total()).unwrap_or_default();
+			if !total.is_zero() {
+				T::DustRemoval::on_unbalanced(NegativeImbalance::new(total));
+				Self::deposit_event(RawEvent::DustLost(who.clone(), total));
+			}
+			*account = None;
+		});
 	}
 }
 

frame/balances/src/tests.rs

@@ -61,6 +61,14 @@ macro_rules! decl_tests {
 			DispatchInfo { weight: w, ..Default::default() }
 		}
 
+		fn events() -> Vec<Event> {
+			let evt = System::events().into_iter().map(|evt| evt.event).collect::<Vec<_>>();
+
+			System::reset_events();
+
+			evt
+		}
+
 		#[test]
 		fn basic_locking_should_work() {
 			<$ext_builder>::default().existential_deposit(1).monied(true).build().execute_with(|| {
@@ -674,5 +682,67 @@ macro_rules! decl_tests {
 					assert_eq!(Balances::reserved_balance(1), 0);
 				});
 		}
+
+		#[test]
+		fn emit_events_with_existential_deposit() {
+			<$ext_builder>::default()
+				.existential_deposit(100)
+				.build()
+				.execute_with(|| {
+					assert_ok!(Balances::set_balance(RawOrigin::Root.into(), 1, 100, 0));
+
+					assert_eq!(
+						events(),
+						[
+							Event::system(system::RawEvent::NewAccount(1)),
+							Event::balances(RawEvent::Endowed(1, 100)),
+							Event::balances(RawEvent::BalanceSet(1, 100, 0)),
+						]
+					);
+
+					let _ = Balances::slash(&1, 1);
+
+					assert_eq!(
+						events(),
+						[
+							Event::balances(RawEvent::DustLost(1, 99)),
+							Event::system(system::RawEvent::KilledAccount(1))
+						]
+					);
+				});
+		}
+
+		#[test]
+		fn emit_events_with_no_existential_deposit_suicide() {
+			<$ext_builder>::default()
+				.existential_deposit(0)
+				.build()
+				.execute_with(|| {
+					assert_ok!(Balances::set_balance(RawOrigin::Root.into(), 1, 100, 0));
+
+					assert_eq!(
+						events(),
+						[
+							Event::system(system::RawEvent::NewAccount(1)),
+							Event::balances(RawEvent::Endowed(1, 100)),
+							Event::balances(RawEvent::BalanceSet(1, 100, 0)),
+						]
+					);
+
+					let _ = Balances::slash(&1, 100);
+
+					// no events
+					assert_eq!(events(), []);
+
+					assert_ok!(System::suicide(Origin::signed(1)));
+
+					assert_eq!(
+						events(),
+						[
+							Event::system(system::RawEvent::KilledAccount(1))
+						]
+					);
+				});
+		}
 	}
 }

frame/balances/src/tests_composite.rs

@@ -26,7 +26,7 @@ use sp_runtime::{
 };
 use sp_core::H256;
 use sp_io;
-use frame_support::{impl_outer_origin, parameter_types};
+use frame_support::{impl_outer_origin, impl_outer_event, parameter_types};
 use frame_support::traits::Get;
 use frame_support::weights::{Weight, DispatchInfo, IdentityFee};
 use std::cell::RefCell;
@@ -37,6 +37,17 @@ impl_outer_origin!{
 	pub enum Origin for Test {}
 }
 
+mod balances {
+	pub use crate::Event;
+}
+
+impl_outer_event! {
+	pub enum Event for Test {
+		system<T>,
+		balances<T>,
+	}
+}
+
 thread_local! {
 	static EXISTENTIAL_DEPOSIT: RefCell<u64> = RefCell::new(0);
 }
@@ -65,7 +76,7 @@ impl frame_system::Trait for Test {
 	type AccountId = u64;
 	type Lookup = IdentityLookup<Self::AccountId>;
 	type Header = Header;
-	type Event = ();
+	type Event = Event;
 	type BlockHashCount = BlockHashCount;
 	type MaximumBlockWeight = MaximumBlockWeight;
 	type DbWeight = ();
@@ -93,7 +104,7 @@ impl pallet_transaction_payment::Trait for Test {
 impl Trait for Test {
 	type Balance = u64;
 	type DustRemoval = ();
-	type Event = ();
+	type Event = Event;
 	type ExistentialDeposit = ExistentialDeposit;
 	type AccountStore = system::Module<Test>;
 }
@@ -138,7 +149,10 @@ impl ExtBuilder {
 				vec![]
 			},
 		}.assimilate_storage(&mut t).unwrap();
-		t.into()
+
+		let mut ext = sp_io::TestExternalities::new(t);
+		ext.execute_with(|| System::set_block_number(1));
+		ext
 	}
 }
 

frame/balances/src/tests_local.rs

@@ -26,7 +26,7 @@ use sp_runtime::{
 };
 use sp_core::H256;
 use sp_io;
-use frame_support::{impl_outer_origin, parameter_types};
+use frame_support::{impl_outer_origin, impl_outer_event, parameter_types};
 use frame_support::traits::{Get, StorageMapShim};
 use frame_support::weights::{Weight, DispatchInfo, IdentityFee};
 use std::cell::RefCell;
@@ -37,6 +37,17 @@ impl_outer_origin!{
 	pub enum Origin for Test {}
 }
 
+mod balances {
+	pub use crate::Event;
+}
+
+impl_outer_event! {
+	pub enum Event for Test {
+		system<T>,
+		balances<T>,
+	}
+}
+
 thread_local! {
 	static EXISTENTIAL_DEPOSIT: RefCell<u64> = RefCell::new(0);
 }
@@ -65,7 +76,7 @@ impl frame_system::Trait for Test {
 	type AccountId = u64;
 	type Lookup = IdentityLookup<Self::AccountId>;
 	type Header = Header;
-	type Event = ();
+	type Event = Event;
 	type BlockHashCount = BlockHashCount;
 	type MaximumBlockWeight = MaximumBlockWeight;
 	type DbWeight = ();
@@ -93,7 +104,7 @@ impl pallet_transaction_payment::Trait for Test {
 impl Trait for Test {
 	type Balance = u64;
 	type DustRemoval = ();
-	type Event = ();
+	type Event = Event;
 	type ExistentialDeposit = ExistentialDeposit;
 	type AccountStore = StorageMapShim<
 		super::Account<Test>,
@@ -146,8 +157,45 @@ impl ExtBuilder {
 				vec![]
 			},
 		}.assimilate_storage(&mut t).unwrap();
-		t.into()
+
+		let mut ext = sp_io::TestExternalities::new(t);
+		ext.execute_with(|| System::set_block_number(1));
+		ext
 	}
 }
 
 decl_tests!{ Test, ExtBuilder, EXISTENTIAL_DEPOSIT }
+
+#[test]
+fn emit_events_with_no_existential_deposit_suicide_with_dust() {
+	<ExtBuilder>::default()
+		.existential_deposit(0)
+		.build()
+		.execute_with(|| {
+			assert_ok!(Balances::set_balance(RawOrigin::Root.into(), 1, 100, 0));
+
+			assert_eq!(
+				events(),
+				[
+					Event::system(system::RawEvent::NewAccount(1)),
+					Event::balances(RawEvent::Endowed(1, 100)),
+					Event::balances(RawEvent::BalanceSet(1, 100, 0)),
+				]
+			);
+
+			let _ = Balances::slash(&1, 99);
+
+			// no events
+			assert_eq!(events(), []);
+
+			assert_ok!(System::suicide(Origin::signed(1)));
+
+			assert_eq!(
+				events(),
+				[
+					Event::balances(RawEvent::DustLost(1, 1)),
+					Event::system(system::RawEvent::KilledAccount(1))
+				]
+			);
+		});
+}

frame/system/src/lib.rs

@@ -742,12 +742,12 @@ decl_module! {
 		/// No DB Read or Write operations because caller is already in overlay
 		/// # </weight>
 		#[weight = (10_000_000, DispatchClass::Operational)]
-		fn suicide(origin) {
+		pub fn suicide(origin) {
 			let who = ensure_signed(origin)?;
 			let account = Account::<T>::get(&who);
 			ensure!(account.refcount == 0, Error::<T>::NonZeroRefCount);
 			ensure!(account.data == T::AccountData::default(), Error::<T>::NonDefaultComposite);
-			Account::<T>::remove(who);
+			Self::kill_account(&who);
 		}
 	}
 }
@@ -1131,6 +1131,15 @@ impl<T: Trait> Module<T> {
 		AllExtrinsicsLen::put(len as u32);
 	}
 
+	/// Reset events. Can be used as an alternative to
+	/// `initialize` for tests that don't need to bother with the other environment entries.
+	#[cfg(any(feature = "std", feature = "runtime-benchmarks", test))]
+	pub fn reset_events() {
+		<Events<T>>::kill();
+		EventCount::kill();
+		<EventTopics<T>>::remove_all();
+	}
+
 	/// Return the chain's current runtime version.
 	pub fn runtime_version() -> RuntimeVersion { T::Version::get() }
 
@@ -1222,8 +1231,8 @@ impl<T: Trait> Module<T> {
 					"WARNING: Referenced account deleted. This is probably a bug."
 				);
 			}
-			Module::<T>::on_killed_account(who.clone());
 		}
+		Module::<T>::on_killed_account(who.clone());
 	}
 
 	/// Determine whether or not it is possible to update the code.