should_panic test

ethcore/src/account.rs

@@ -198,7 +198,11 @@ impl Account {
 	pub fn add_balance(&mut self, x: &U256) { self.balance = self.balance + *x; }
 
 	/// Increment the nonce of the account by one.
-	pub fn sub_balance(&mut self, x: &U256) { self.balance = self.balance - *x; }
+	/// Panics if balance is less than `x`
+	pub fn sub_balance(&mut self, x: &U256) {
+		assert!(self.balance >= *x);
+		self.balance = self.balance - *x;
+	}
 
 	/// Commit the `storage_overlay` to the backing DB and update `storage_root`.
 	pub fn commit_storage(&mut self, db: &mut AccountDBMut) {

ethcore/src/externalities.rs

@@ -355,6 +355,7 @@ mod tests {
 	}
 
 	#[test]
+	#[should_panic]
 	fn can_call_fail_empty() {
 		let mut setup = TestSetup::new();
 		let state = setup.state.reference_mut();