@0x/contracts-staking: Add _computePoolRewardsSplit() tests to MixinStakingPoolRewards unit tests.

contracts/staking/contracts/test/TestMixinStakingPoolRewards.sol

@@ -116,6 +116,23 @@ contract TestMixinStakingPoolRewards is
         return _syncPoolRewards(poolId, reward, membersStake);
     }
 
+    // Expose `_computePoolRewardsSplit()` for testing.
+    function computePoolRewardsSplit(
+        uint32 operatorShare,
+        uint256 totalReward,
+        uint256 membersStake
+    )
+        external
+        pure
+        returns (uint256 operatorReward, uint256 membersReward)
+    {
+        return _computePoolRewardsSplit(
+            operatorShare,
+            totalReward,
+            membersStake
+        );
+    }
+
     // Access `_delegatedStakeToPoolByOwner`
     function delegatedStakeToPoolByOwner(address member, bytes32 poolId)
         external

contracts/staking/test/unit_tests/mixin_staking_pool_rewards.ts

@@ -417,5 +417,68 @@ blockchainTests.resets('MixinStakingPoolRewards unit tests', env => {
             verifyEventsFromLogs(logs, [], Events.Transfer);
         });
     });
+
+    describe('_computePoolRewardsSplit', () => {
+        it("gives all rewards to operator if members' stake is zero", async () => {
+            const operatorShare = getRandomPortion(constants.PPM_100_PERCENT);
+            const totalReward = getRandomInteger(1, 1e18);
+            const membersStake = constants.ZERO_AMOUNT;
+            const [operatorReward, membersReward] = await testContract.computePoolRewardsSplit.callAsync(
+                operatorShare,
+                totalReward,
+                membersStake,
+            );
+            expect(operatorReward).to.bignumber.eq(totalReward);
+            expect(membersReward).to.bignumber.eq(0);
+        });
+        it("gives all rewards to operator if members' stake is zero and operator share is zero", async () => {
+            const operatorShare = constants.ZERO_AMOUNT;
+            const totalReward = getRandomInteger(1, 1e18);
+            const membersStake = constants.ZERO_AMOUNT;
+            const [operatorReward, membersReward] = await testContract.computePoolRewardsSplit.callAsync(
+                operatorShare,
+                totalReward,
+                membersStake,
+            );
+            expect(operatorReward).to.bignumber.eq(totalReward);
+            expect(membersReward).to.bignumber.eq(0);
+        });
+        it('gives all rewards to operator if operator share is 100%', async () => {
+            const operatorShare = constants.PPM_100_PERCENT;
+            const totalReward = getRandomInteger(1, 1e18);
+            const membersStake = getRandomInteger(1, 1e18);
+            const [operatorReward, membersReward] = await testContract.computePoolRewardsSplit.callAsync(
+                operatorShare,
+                totalReward,
+                membersStake,
+            );
+            expect(operatorReward).to.bignumber.eq(totalReward);
+            expect(membersReward).to.bignumber.eq(0);
+        });
+        it('gives all rewards to members if operator share is 0%', async () => {
+            const operatorShare = constants.ZERO_AMOUNT;
+            const totalReward = getRandomInteger(1, 1e18);
+            const membersStake = getRandomInteger(1, 1e18);
+            const [operatorReward, membersReward] = await testContract.computePoolRewardsSplit.callAsync(
+                operatorShare,
+                totalReward,
+                membersStake,
+            );
+            expect(operatorReward).to.bignumber.eq(0);
+            expect(membersReward).to.bignumber.eq(totalReward);
+        });
+        it('splits rewards between operator and members based on operator share', async () => {
+            const operatorShare = getRandomPortion(constants.PPM_100_PERCENT);
+            const totalReward = getRandomInteger(1, 1e18);
+            const membersStake = getRandomInteger(1, 1e18);
+            const [operatorReward, membersReward] = await testContract.computePoolRewardsSplit.callAsync(
+                operatorShare,
+                totalReward,
+                membersStake,
+            );
+            expect(operatorReward).to.bignumber.eq(toOperatorPortion(operatorShare, totalReward));
+            expect(membersReward).to.bignumber.eq(toMembersPortion(operatorShare, totalReward));
+        });
+    });
 });
 // tslint:disable: max-file-line-count