bonding: Update reward cut logic to match LIP

It is a little less exact (might overmint on the last reward call), but the simpler logic might be just worth it.
livepeer · Jul 21, 2023 · 90f63e5 · 90f63e5
1 parent f580f29
commit 90f63e5
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Showing 2 changed files with 37 additions and 32 deletions.
diff --git a/contracts/bonding/BondingManager.sol b/contracts/bonding/BondingManager.sol
@@ -873,29 +873,25 @@ contract BondingManager is ManagerProxyTarget, IBondingManager {
             earningsPool.setStake(t.earningsPoolPerRound[lastUpdateRound].totalStake);
         }
 
+        if (treasuryBalanceCeiling > 0) {
+            uint256 treasuryBalance = livepeerToken().balanceOf(treasury());
+            if (treasuryBalance >= treasuryBalanceCeiling) {
+                // halt treasury contributions until the cut rate param is updated again
+                treasuryRewardCutRate = 0;
+            }
+        }
+
         // Create reward based on active transcoder's stake relative to the total active stake
         // rewardTokens = (current mintable tokens for the round * active transcoder stake) / total active stake
         IMinter mtr = minter();
         uint256 totalRewardTokens = mtr.createReward(earningsPool.totalStake, currentRoundTotalActiveStake);
-
         uint256 treasuryRewards = PreciseMathUtils.percOf(totalRewardTokens, treasuryRewardCutRate);
         if (treasuryRewards > 0) {
-            address trsy = treasury();
-            uint256 treasuryBalance = livepeerToken().balanceOf(trsy);
-
-            uint256 maxTreasuryRewards = treasuryBalanceCeiling > treasuryBalance
-                ? treasuryBalanceCeiling - treasuryBalance
-                : 0;
-            if (treasuryRewards > maxTreasuryRewards) {
-                treasuryRewards = maxTreasuryRewards;
-                // halt treasury contributions until the cut rate param is updated again
-                treasuryRewardCutRate = 0;
-            }
+            address trsry = treasury();
 
-            if (treasuryRewards > 0) {
-                mtr.trustedTransferTokens(trsy, treasuryRewards);
-                emit TreasuryReward(msg.sender, trsy, treasuryRewards);
-            }
+            mtr.trustedTransferTokens(trsry, treasuryRewards);
+
+            emit TreasuryReward(msg.sender, trsry, treasuryRewards);
         }
 
         uint256 transcoderRewards = totalRewardTokens.sub(treasuryRewards);

diff --git a/test/unit/BondingManager.js b/test/unit/BondingManager.js
@@ -4800,26 +4800,35 @@ describe("BondingManager", () => {
             })
 
             describe("ceiling behavior", () => {
-                beforeEach(async () => {
-                    await fixture.token.setMockUint256(
-                        functionSig("balanceOf(address)"),
-                        990
-                    )
-                })
+                describe("under the limit", () => {
+                    beforeEach(async () => {
+                        await fixture.token.setMockUint256(
+                            functionSig("balanceOf(address)"),
+                            990
+                        )
+                    })
 
-                it("should limit contribution to ceiling", async () => {
-                    const tx = await bondingManager.connect(transcoder).reward()
+                    it("should contribute normally", async () => {
+                        const tx = await bondingManager
+                            .connect(transcoder)
+                            .reward()
 
-                    await expect(tx)
-                        .to.emit(fixture.minter, "TrustedTransferTokens")
-                        .withArgs(fixture.treasury.address, 10) // 1000 - 990
-                })
+                        await expect(tx)
+                            .to.emit(fixture.minter, "TrustedTransferTokens")
+                            .withArgs(fixture.treasury.address, 63)
+                    })
 
-                it("should clear treasuryRewardCutRate param", async () => {
-                    await bondingManager.connect(transcoder).reward()
+                    it("should not clear treasuryRewardCutRate param", async () => {
+                        await bondingManager.connect(transcoder).reward()
 
-                    const cutRate = await bondingManager.treasuryRewardCutRate()
-                    assert.equal(cutRate.toNumber(), 0, "cut rate not cleared")
+                        const cutRate =
+                            await bondingManager.treasuryRewardCutRate()
+                        assert.equal(
+                            cutRate.toString(),
+                            TREASURY_CUT.toString(),
+                            "cut rate updated"
+                        )
+                    })
                 })
 
                 describe("when at limit", () => {