fix(pallet-dao): expired proposal approval (#887)

substrate-node/pallets/pallet-dao/src/dao.rs

@@ -205,17 +205,20 @@ impl<T: Config> Pallet<T> {
         let no_votes = voting.nays.len() as u32;
         let yes_votes = voting.ayes.len() as u32;
 
+        let threshold_is_met = (no_votes + yes_votes) >= voting.threshold;
+        let proposal_is_expired = frame_system::Pallet::<T>::block_number() >= voting.end;
+
         // Only allow actual closing of the proposal after the voting threshold is met or voting period has ended
         ensure!(
-            (no_votes + yes_votes) >= voting.threshold
-                || frame_system::Pallet::<T>::block_number() >= voting.end,
+            threshold_is_met || proposal_is_expired,
             Error::<T>::OngoingVoteAndTresholdStillNotMet
         );
 
         let total_aye_weight: u64 = voting.ayes.iter().map(|y| y.weight).sum();
         let total_naye_weight: u64 = voting.nays.iter().map(|y| y.weight).sum();
 
-        let approved = total_aye_weight > total_naye_weight;
+        // Only approve proposal if the voting threshold is met and simple majority (expressed in weight) is reached
+        let approved = threshold_is_met && (total_aye_weight > total_naye_weight);
 
         if approved {
             let proposal = Self::validate_and_get_proposal(&proposal_hash)?;

substrate-node/pallets/pallet-dao/src/tests.rs

@@ -262,6 +262,52 @@ fn close_after_proposal_duration_works() {
     });
 }
 
+#[test]
+fn close_after_proposal_duration_threshold_not_met_works() {
+    new_test_ext().execute_with(|| {
+        System::set_block_number(1);
+
+        let proposal = make_proposal(b"some_remark".to_vec());
+        let hash = BlakeTwo256::hash_of(&proposal);
+        let threshold = 2;
+
+        assert_ok!(DaoModule::propose(
+            RuntimeOrigin::signed(1),
+            threshold,
+            Box::new(proposal.clone()),
+            b"some_description".to_vec(),
+            b"some_link".to_vec(),
+            None
+        ));
+        let proposal_index = 0;
+
+        // Farmer 1 votes yes
+        let farm_id = 1;
+        prepare_twin_farm_and_node(10, b"farm1".to_vec(), farm_id);
+        assert_ok!(DaoModule::vote(
+            RuntimeOrigin::signed(10),
+            farm_id,
+            hash.clone(),
+            true
+        ));
+
+        System::set_block_number(5); // default duration is 4 blocks
+        assert_ok!(DaoModule::close(
+            RuntimeOrigin::signed(2),
+            hash.clone(),
+            proposal_index
+        ));
+
+        let e = System::events();
+        assert_eq!(
+            e[6],
+            record(MockEvent::DaoModule(DaoEvent::Disapproved {
+                proposal_hash: hash,
+            }))
+        );
+    });
+}
+
 #[test]
 fn close_if_not_council_member_fails() {
     new_test_ext().execute_with(|| {