Tests are passing and ran linter

contracts/staking/contracts/src/staking_pools/MixinCumulativeRewards.sol

@@ -162,29 +162,37 @@ contract MixinCumulativeRewards is
     function _trySetMostRecentCumulativeRewardEpoch(bytes32 poolId, uint256 epoch)
         internal
     {
-        // load the current value, sanity check that we're not trying to go back in time
-        uint256 currentMostRecentEpoch = cumulativeRewardsByPoolLastStored[poolId];
-        assert(epoch >= currentMostRecentEpoch);
-
         // check if we should do any work
+        uint256 currentMostRecentEpoch = cumulativeRewardsByPoolLastStored[poolId];
         if (epoch == currentMostRecentEpoch) {
             return;
         }
 
         // update state to reflect the most recent cumulative reward
-        _forceSetMostRecentCumulativeRewardEpoch(poolId, epoch);
+        _forceSetMostRecentCumulativeRewardEpoch(
-
+            poolId,
-        // unset the previous most recent reward, if it is no longer needed
+            currentMostRecentEpoch,
-        _tryUnsetCumulativeReward(poolId, currentMostRecentEpoch);
+            epoch
+        );
     }
 
     /// @dev Forcefully sets the epoch of the most recent cumulative reward.
     /// @param poolId Unique Id of pool.
-    /// @param epoch of the most recent cumulative reward.
+    /// @param currentMostRecentEpoch of the most recent cumulative reward.
-    function _forceSetMostRecentCumulativeRewardEpoch(bytes32 poolId, uint256 epoch)
+    /// @param newMostRecentEpoch of the new most recent cumulative reward.
+    function _forceSetMostRecentCumulativeRewardEpoch(
+        bytes32 poolId,
+        uint256 currentMostRecentEpoch,
+        uint256 newMostRecentEpoch
+    )
         internal
     {
-        cumulativeRewardsByPoolLastStored[poolId] = epoch;
+        // sanity check that we're not trying to go back in time
+        assert(newMostRecentEpoch >= currentMostRecentEpoch);
+        cumulativeRewardsByPoolLastStored[poolId] = newMostRecentEpoch;
+
+        // unset the previous most recent reward, if it is no longer needed
+        _tryUnsetCumulativeReward(poolId, currentMostRecentEpoch);
     }
 
     /// @dev Adds a dependency on a cumulative reward for a given epoch.
@@ -209,8 +217,7 @@ contract MixinCumulativeRewards is
         } else {
             _removeDependencyOnCumulativeReward(
                 poolId,
-                epoch,
+                epoch
-                mostRecentCumulativeRewardInfo.cumulativeRewardEpoch
             );
         }
     }
@@ -240,11 +247,9 @@ contract MixinCumulativeRewards is
     /// @dev Removes a dependency on a cumulative reward for a given epoch.
     /// @param poolId Unique Id of pool.
     /// @param epoch to remove dependency from.
-    /// @param mostRecentCumulativeRewardEpoch Epoch of the most recent cumulative reward.
     function _removeDependencyOnCumulativeReward(
         bytes32 poolId,
-        uint256 epoch,
+        uint256 epoch
-        uint256 mostRecentCumulativeRewardEpoch
     )
         internal
     {

contracts/staking/contracts/src/staking_pools/MixinStakingPoolRewards.sol

@@ -135,7 +135,7 @@ contract MixinStakingPoolRewards is
         );
 
         // store cumulative rewards and set most recent
-        _trySetCumulativeReward(
+        _forceSetCumulativeReward(
             poolId,
             epoch,
             IStructs.Fraction({

contracts/staking/contracts/test/TestCumulativeRewardTracking.sol

@@ -48,7 +48,11 @@ contract TestCumulativeRewardTracking is
         internal
     {
         emit SetCumulativeReward(poolId, epoch);
-        MixinCumulativeRewards._forceSetCumulativeReward(poolId, epoch, value);
+        MixinCumulativeRewards._forceSetCumulativeReward(
+            poolId,
+            epoch,
+            value
+        );
     }
 
     function _forceUnsetCumulativeReward(bytes32 poolId, uint256 epoch)
@@ -58,18 +62,26 @@ contract TestCumulativeRewardTracking is
         MixinCumulativeRewards._forceUnsetCumulativeReward(poolId, epoch);
     }
 
-    function _forceSetMostRecentCumulativeRewardEpoch(bytes32 poolId, uint256 epoch)
+    function _forceSetMostRecentCumulativeRewardEpoch(
+        bytes32 poolId,
+        uint256 currentMostRecentEpoch,
+        uint256 newMostRecentEpoch
+    )
         internal
     {
-        emit SetMostRecentCumulativeReward(poolId, epoch);
+        emit SetMostRecentCumulativeReward(poolId, newMostRecentEpoch);
-        MixinCumulativeRewards._forceSetMostRecentCumulativeRewardEpoch(poolId, epoch);
+        MixinCumulativeRewards._forceSetMostRecentCumulativeRewardEpoch(
+            poolId,
+            currentMostRecentEpoch,
+            newMostRecentEpoch
+        );
     }
 
     function _assertMixinParamsBeforeInit()
         internal
-    {}
+    {} // solhint-disable-line no-empty-blocks
 
     function _assertMixinSchedulerBeforeInit()
         internal
-    {}
+    {} // solhint-disable-line no-empty-blocks
 }

contracts/staking/test/cumulative_reward_tracking_test.ts

@@ -35,11 +35,7 @@ blockchainTests.resets('Cumulative Reward Tracking', env => {
 
     describe('Tracking Cumulative Rewards (CR)', () => {
         it('should set CR hen a pool is created is epoch 0', async () => {
-            await simulation.runTestAsync(
+            await simulation.runTestAsync([], [TestAction.CreatePool], [{ event: 'SetCumulativeReward', epoch: 0 }]);
-                [],
-                [TestAction.CreatePool],
-                [{ event: 'SetCumulativeReward', epoch: 0 }],
-            );
         });
         it('should set CR and Most Recent CR when a pool is created in epoch >0', async () => {
             await simulation.runTestAsync(

contracts/staking/test/utils/cumulative_reward_tracking_simulation.ts

@@ -37,20 +37,20 @@ export class CumulativeRewardTrackingSimulation {
     private static _extractTestLogs(txReceiptLogs: DecodedLogArgs[]): TestLog[] {
         const logs = [];
         for (const log of txReceiptLogs) {
-            if ((log as DecodedLogArgs).event === 'SetMostRecentCumulativeReward') {
+            if (log.event === 'SetMostRecentCumulativeReward') {
                 logs.push({
                     event: 'SetMostRecentCumulativeReward',
-                    epoch: (log as DecodedLogArgs).args.epoch.toNumber(),
+                    epoch: log.args.epoch.toNumber(),
                 });
-            } else if ((log as DecodedLogArgs).event === 'SetCumulativeReward') {
+            } else if (log.event === 'SetCumulativeReward') {
                 logs.push({
                     event: 'SetCumulativeReward',
-                    epoch: (log as DecodedLogArgs).args.epoch.toNumber(),
+                    epoch: log.args.epoch.toNumber(),
                 });
-            } else if ((log as DecodedLogArgs).event === 'UnsetCumulativeReward') {
+            } else if (log.event === 'UnsetCumulativeReward') {
                 logs.push({
                     event: 'UnsetCumulativeReward',
-                    epoch: (log as DecodedLogArgs).args.epoch.toNumber(),
+                    epoch: log.args.epoch.toNumber(),
                 });
             }
         }
@@ -159,6 +159,7 @@ export class CumulativeRewardTrackingSimulation {
                         { from: this._poolOperator },
                     );
                     const createStakingPoolLog = txReceipt.logs[0];
+                    // tslint:disable-next-line no-unnecessary-type-assertion
                     this._poolId = (createStakingPoolLog as DecodedLogArgs).args.poolId;
                     break;