Make the proposal/quorum thresholds updatable (#165)

* Make the proposal/quorum thresholds updatable

* Test threshold updating

contracts/treasury/CHANGELOG.json

@@ -1,4 +1,13 @@
 [
+    {
+        "version": "1.1.0",
+        "changes": [
+            {
+                "note": "Make the proposal/quorum thresholds updatable",
+                "pr": 165
+            }
+        ]
+    },
     {
         "timestamp": 1614141718,
         "version": "1.0.2",

contracts/treasury/contracts/src/IZrxTreasury.sol

@@ -96,6 +96,18 @@ interface IZrxTreasury {
         view
         returns (uint256);
 
+    /// @dev Updates the proposal and quorum thresholds to the given
+    ///      values. Note that this function is only callable by the
+    ///      treasury contract itself, so the threshold can only be
+    ///      updated via a successful treasury proposal.
+    /// @param newProposalThreshold The new value for the proposal threshold.
+    /// @param newQuorumThreshold The new value for the quorum threshold.
+    function updateThresholds(
+        uint256 newProposalThreshold,
+        uint256 newQuorumThreshold
+    )
+        external;
+
     /// @dev Creates a proposal to send ZRX from this treasury on the
     ///      the given actions. Must have at least `proposalThreshold`
     ///      of voting power to call this function. See `getVotingPower`

contracts/treasury/contracts/src/ZrxTreasury.sol

@@ -42,8 +42,8 @@ contract ZrxTreasury is
     DefaultPoolOperator public immutable override defaultPoolOperator;
     bytes32 public immutable override defaultPoolId;
     uint256 public immutable override votingPeriod;
-    uint256 public immutable override proposalThreshold;
-    uint256 public immutable override quorumThreshold;
+    uint256 public override proposalThreshold;
+    uint256 public override quorumThreshold;
 
     // Storage
     Proposal[] public proposals;
@@ -82,6 +82,24 @@ contract ZrxTreasury is
     receive() external payable {}
     // solhint-enable
 
+    /// @dev Updates the proposal and quorum thresholds to the given
+    ///      values. Note that this function is only callable by the
+    ///      treasury contract itself, so the threshold can only be
+    ///      updated via a successful treasury proposal.
+    /// @param newProposalThreshold The new value for the proposal threshold.
+    /// @param newQuorumThreshold The new value for the quorum threshold.
+    function updateThresholds(
+        uint256 newProposalThreshold,
+        uint256 newQuorumThreshold
+    )
+        external
+        override
+    {
+        require(msg.sender == address(this), "updateThresholds/ONLY_SELF");
+        proposalThreshold = newProposalThreshold;
+        quorumThreshold = newQuorumThreshold;
+    }
+
     /// @dev Creates a proposal to send ZRX from this treasury on the
     ///      the given actions. Must have at least `proposalThreshold`
     ///      of voting power to call this function. See `getVotingPower`

contracts/treasury/test/treasury_test.ts

@@ -580,4 +580,47 @@ blockchainTests.resets('Treasury governance', env => {
             expect(await weth.balanceOf(staking.address).callAsync()).to.bignumber.equal(wethAmount);
         });
     });
+    describe('Can update thresholds via proposal', () => {
+        it('Updates proposal and quorum thresholds', async () => {
+            // Delegator has enough ZRX to create and pass a proposal
+            await staking.stake(TREASURY_PARAMS.quorumThreshold).awaitTransactionSuccessAsync({ from: delegator });
+            await staking
+                .moveStake(
+                    new StakeInfo(StakeStatus.Undelegated),
+                    new StakeInfo(StakeStatus.Delegated, defaultPoolId),
+                    TREASURY_PARAMS.quorumThreshold,
+                )
+                .awaitTransactionSuccessAsync({ from: delegator });
+            await fastForwardToNextEpochAsync();
+            const currentEpoch = await staking.currentEpoch().callAsync();
+            const newProposalThreshold = new BigNumber(420);
+            const newQuorumThreshold = new BigNumber(1337);
+            const updateThresholdsAction = {
+                target: treasury.address,
+                data: treasury
+                    .updateThresholds(newProposalThreshold, newQuorumThreshold)
+                    .getABIEncodedTransactionData(),
+                value: constants.ZERO_AMOUNT,
+            };
+            const tx = treasury.propose(
+                [updateThresholdsAction],
+                currentEpoch.plus(3),
+                `Updates proposal threshold to ${newProposalThreshold} and quorum threshold to ${newQuorumThreshold}`,
+                [],
+            );
+            const proposalId = await tx.callAsync({ from: delegator });
+            await tx.awaitTransactionSuccessAsync({ from: delegator });
+            await fastForwardToNextEpochAsync();
+            await fastForwardToNextEpochAsync();
+            await treasury.castVote(proposalId, true, []).awaitTransactionSuccessAsync({ from: delegator });
+            await fastForwardToNextEpochAsync();
+            await treasury
+                .execute(proposalId, [updateThresholdsAction])
+                .awaitTransactionSuccessAsync({ from: delegator });
+            const proposalThreshold = await treasury.proposalThreshold().callAsync();
+            const quorumThreshold = await treasury.quorumThreshold().callAsync();
+            expect(proposalThreshold).to.bignumber.equal(newProposalThreshold);
+            expect(quorumThreshold).to.bignumber.equal(newQuorumThreshold);
+        });
+    });
 });