feat: return 0 on duplicate claim

INTEGRATION.MD

@@ -0,0 +1,8 @@
+# Risks to integrators
+
+Somebody could claim on your behalf
+
+Votes not meeting the threshold may result in 0 rewards
+
+Claiming more than once will return 0
+

src/Governance.sol

@@ -581,13 +581,18 @@ contract Governance is Multicall, UserProxyFactory, ReentrancyGuard, IGovernance
         (VoteSnapshot memory votesSnapshot_,) = _snapshotVotes();
         (InitiativeVoteSnapshot memory votesForInitiativeSnapshot_, InitiativeState memory initiativeState_) = _snapshotVotesForInitiative(_initiative);
 
-        /// Invariant: Must only claim once or unregister
-        require(initiativeState_.lastEpochClaim < epoch() - 1, "Governance: already-claimed"); /// TODO: Merge into rest
-        // TODO: We can do a early return instead
-
         // TODO: Return type from state FSM can be standardized
         (, bool canClaimRewards, ) = getInitiativeState(_initiative);
-        require(canClaimRewards, "Governance: claim-not-met");
+
+        /// @audit Return 0 if we cannot claim
+        /// INVARIANT:
+        /// We cannot claim only for 2 reasons:
+        /// We have already claimed
+        /// We do not meet the threshold
+        /// TODO: Enforce this with assertions
+        if(!canClaimRewards) {
+            return 0;
+        }
         // if(!canClaimRewards) {
         //     return 0;
         // }

test/Governance.t.sol

@@ -1126,14 +1126,11 @@ contract GovernanceTest is Test {
 
         // should compute the claim and transfer it to the initiative
         assertEq(governance.claimForInitiative(baseInitiative1), 5000e18);
-
-        vm.expectRevert("Governance: already-claimed"); /// @audit TODO: Decide if we should not revert
-        governance.claimForInitiative(baseInitiative1);
+        // 2nd claim = 0
+        assertEq(governance.claimForInitiative(baseInitiative1), 0);
 
         assertEq(governance.claimForInitiative(baseInitiative2), 5000e18);
-
-        vm.expectRevert("Governance: already-claimed");
-        governance.claimForInitiative(baseInitiative2);
+        assertEq(governance.claimForInitiative(baseInitiative2), 0);
 
         assertEq(lusd.balanceOf(baseInitiative2), 5000e18);
 
@@ -1154,21 +1151,13 @@ contract GovernanceTest is Test {
         vm.warp(block.timestamp + governance.EPOCH_DURATION() + 1);
 
         assertEq(governance.claimForInitiative(baseInitiative1), 10000e18);
+        assertEq(governance.claimForInitiative(baseInitiative1), 0);
 
-        vm.expectRevert("Governance: already-claimed");
-        governance.claimForInitiative(baseInitiative1);
 
         assertEq(lusd.balanceOf(baseInitiative1), 15000e18);
 
-        // TODO: This should most likely either return 0 or we accept the claim not met
-        /// Claim not met is kind of a weird thing to return tbh
-        /// @audit THIS FAILS ON PURPOSE
-        /// TODO: Let's fix this by fixing single claiming
-        /// Let's decide how to handle 0 rewards case and then decide
         assertEq(governance.claimForInitiative(baseInitiative2), 0);
-
-        vm.expectRevert("Governance: already-claimed");
-        governance.claimForInitiative(baseInitiative2);
+        assertEq(governance.claimForInitiative(baseInitiative2), 0);
 
         assertEq(lusd.balanceOf(baseInitiative2), 5000e18);