Auction improvements

contracts/staking/stakeManager/StakeManager.sol

@@ -190,6 +190,14 @@ contract StakeManager is
         Governance Methods
      */
 
+    function setMinBidStakeFraction(uint256 fraction) public onlyGovernance {
+        minBidStakeFraction = fraction;
+    }
+
+    function setBidCooldown(uint256 cooldown) public onlyGovernance {
+        bidCooldown = cooldown;
+    }
+
     function setDelegationEnabled(bool enabled) public onlyGovernance {
         delegationEnabled = enabled;
     }
@@ -451,7 +459,7 @@ contract StakeManager is
         bytes memory signerPubkey
     ) public onlyWhenUnlocked {
         require(currentValidatorSetSize() < validatorThreshold, "no more slots");
-        require(amount >= minDeposit, "not enough deposit");
+        require(amount >= validatorState.amount.mul(minBidStakeFraction).div(MIN_BID_PRECISION), "not enough deposit");
         _transferAndTopUp(user, msg.sender, heimdallFee, amount);
         _stakeFor(user, amount, acceptDelegation, signerPubkey);
     }

contracts/staking/stakeManager/StakeManagerExtension.sol

@@ -38,9 +38,9 @@ contract StakeManagerExtension is StakeManagerStorage, Initializable, StakeManag
         );
 
         uint256 _currentEpoch = currentEpoch;
-        uint256 _replacementCoolDown = replacementCoolDown;
+        uint256 cooldown = replacementCoolDown;
         // when dynasty period is updated validators are in cooldown period
-        require(_replacementCoolDown == 0 || _replacementCoolDown <= _currentEpoch, "Cooldown period");
+        require(cooldown == 0 || cooldown <= _currentEpoch, "Cooldown period");
         // (auctionPeriod--dynasty)--(auctionPeriod--dynasty)--(auctionPeriod--dynasty)
         // if it's auctionPeriod then will get residue smaller then auctionPeriod
         // from (CurrentPeriod of validator )%(auctionPeriod--dynasty)
@@ -57,9 +57,17 @@ contract StakeManagerExtension is StakeManagerStorage, Initializable, StakeManag
         perceivedStake = perceivedStake.add(validators[validatorId].delegatedAmount);
 
         Auction storage auction = validatorAuction[validatorId];
+
+        // do not allow bidding too often
+        cooldown = lastBidTimestamp[msg.sender];
+        require(cooldown == 0 || cooldown < block.timestamp, "bid too often");
+
         uint256 currentAuctionAmount = auction.amount;
 
-        perceivedStake = Math.max(perceivedStake, currentAuctionAmount);
+        perceivedStake = Math.max(
+            validatorState.amount.mul(minBidStakeFraction).div(MIN_BID_PRECISION), 
+            Math.max(perceivedStake, currentAuctionAmount)
+        );
 
         require(perceivedStake < amount, "Must bid higher");
         require(token.transferFrom(msg.sender, address(this), amount), "Transfer failed");
@@ -74,6 +82,7 @@ contract StakeManagerExtension is StakeManagerStorage, Initializable, StakeManag
         auction.user = msg.sender;
         auction.acceptDelegation = _acceptDelegation;
         auction.signerPubkey = _signerPubkey;
+        lastBidTimestamp[msg.sender] = block.timestamp + bidCooldown;
 
         logger.logStartAuction(validatorId, currentValidatorAmount, amount);
     }

contracts/staking/stakeManager/StakeManagerStorage.sol

@@ -51,6 +51,7 @@ contract StakeManagerStorage is GovernanceLockable, RootChainable {
     uint256 constant REWARD_PRECISION = 10**25;
     uint256 internal constant INCORRECT_VALIDATOR_ID = 2**256 - 1;
     uint256 internal constant INITIALIZED_AMOUNT = 1;
+    uint256 constant CHK_REWARD_PRECISION = 100;
 
     IERC20 public token;
     address public registry;

contracts/staking/stakeManager/StakeManagerStorageExtension.sol

@@ -1,17 +1,24 @@
 pragma solidity 0.5.17;
 
 contract StakeManagerStorageExtension {
+    uint256 public constant MIN_BID_PRECISION = 10000; // down to 0.0001% fractions
+
     address public eventsHub;
     uint256 public rewardPerStake;
     address public extensionCode;
     address[] public signers;
 
-    uint256 constant CHK_REWARD_PRECISION = 100;
     uint256 public prevBlockInterval;
     // how much less reward per skipped checkpoint, 0 - 100%
     uint256 public rewardDecreasePerCheckpoint;
     // how many checkpoints to reward
     uint256 public maxRewardedCheckpoints;
     // increase / decrease value for faster or slower checkpoints, 0 - 100%
     uint256 public checkpointRewardDelta;
+    // do not prevent bidding for some time to incentivize early bidding
+    uint256 public bidCooldown;
+    // fraction of the total stake acting as a minimum for auction bidding, 
+    uint256 public minBidStakeFraction; 
+    // tracks when auction bid happened for the user
+    mapping(address => uint256) public lastBidTimestamp;
 }   

test/helpers/deployer.js

@@ -171,6 +171,20 @@ class Deployer {
         stakeManager.contract.methods.updateCheckpointRewardParams(val1, val2, val3).encodeABI()
       )
     }
+
+    stakeManager.setBidCooldown = (cooldown) => {
+      return governance.update(
+        stakeManager.address,
+        stakeManager.contract.methods.setBidCooldown(cooldown).encodeABI()
+      )
+    }
+
+    stakeManager.setMinBidStakeFraction = (fraction) => {
+      return governance.update(
+        stakeManager.address,
+        stakeManager.contract.methods.setMinBidStakeFraction(fraction).encodeABI()
+      )
+    }
   }
 
   async deployStakeManager(wallets) {

test/units/staking/stakeManager/StakeManager.Staking.js

@@ -6,6 +6,7 @@ import {
 } from '../../../helpers/utils.js'
 import { expectEvent, expectRevert, BN } from '@openzeppelin/test-helpers'
 import { wallets, walletAmounts, freshDeploy, approveAndStake } from '../deployment'
+const { toWei } = web3.utils
 
 module.exports = function(accounts) {
   let owner = accounts[0]
@@ -17,7 +18,7 @@ module.exports = function(accounts) {
       let _aproveAmount = aproveAmount || walletAmounts[user].amount
       let _stakeAmount = stakeAmount || walletAmounts[user].stakeAmount
 
-      await approveAndStake.call(this, { wallet, stakeAmount: _stakeAmount, approveAmount: _aproveAmount, noMinting, signer })
+      return approveAndStake.call(this, { wallet, stakeAmount: _stakeAmount, approveAmount: _aproveAmount, noMinting, signer })
     }
   }
 
@@ -76,7 +77,7 @@ module.exports = function(accounts) {
       })
     }
 
-    function testStake(user, userPubkey, amount, stakeAmount, validatorId, fee) {
+    function testStake({ user, userPubkey, amount, stakeAmount, validatorId, fee, totalStake }) {
       before('Approve', async function() {
         this.user = user
         this.fee = new BN(fee || this.defaultHeimdallFee)
@@ -116,7 +117,7 @@ module.exports = function(accounts) {
 
       it('must have correct total staked balance', async function() {
         const stake = await this.stakeManager.currentValidatorSetTotalStake()
-        assertBigNumberEquality(stake, stakeAmount)
+        assertBigNumberEquality(stake, totalStake || stakeAmount)
       })
 
       it(`must have validatorId == ${validatorId}`, async function() {
@@ -174,21 +175,21 @@ module.exports = function(accounts) {
 
       describe('when stakes first time', function() {
         const amounts = walletAmounts[wallets[1].getAddressString()]
-        testStake(
-          wallets[1].getChecksumAddressString(),
-          wallets[1].getPublicKeyString(),
-          amounts.amount,
-          amounts.stakeAmount,
-          1
-        )
+        testStake({
+          user: wallets[1].getChecksumAddressString(),
+          userPubkey: wallets[1].getPublicKeyString(),
+          amount: amounts.amount,
+          stakeAmount: amounts.stakeAmount,
+          validatorId: 1
+        })
       })
 
       describe('when stakes again', function() {
         testStakeRevert(
           wallets[1].getChecksumAddressString(),
           wallets[1].getPublicKeyString(),
-          web3.utils.toWei('200'),
-          web3.utils.toWei('200')
+          toWei('200'),
+          toWei('200')
         )
       })
     })
@@ -213,13 +214,13 @@ module.exports = function(accounts) {
         testStakeRevert(
           wallets[2].getChecksumAddressString(),
           wallets[2].getPublicKeyString(),
-          web3.utils.toWei('250'),
-          web3.utils.toWei('150')
+          toWei('250'),
+          toWei('150')
         )
       })
       describe('when reStakes while on going auction', function() {
         it('when auction is active', async function() {
-          let auctionBid = web3.utils.toWei('10000')
+          let auctionBid = toWei('10000')
           const auctionUser = wallets[4].getAddressString()
           await this.stakeToken.mint(auctionUser, auctionBid)
           await this.stakeToken.approve(this.stakeManager.address, auctionBid, {
@@ -245,21 +246,21 @@ module.exports = function(accounts) {
 
       describe('when user stakes', function() {
         const amounts = walletAmounts[wallets[3].getAddressString()]
-        testStake(
-          wallets[3].getChecksumAddressString(),
-          wallets[3].getPublicKeyString(),
-          amounts.amount,
-          amounts.stakeAmount,
-          1
-        )
+        testStake({
+          user: wallets[3].getChecksumAddressString(),
+          userPubkey: wallets[3].getPublicKeyString(),
+          amount: amounts.amount,
+          stakeAmount: amounts.stakeAmount,
+          validatorId: 1
+        })
       })
 
       describe('when other user stakes beyond validator threshold', function() {
         testStakeRevert(
           wallets[4].getChecksumAddressString(),
           wallets[4].getPublicKeyString(),
-          web3.utils.toWei('100'),
-          web3.utils.toWei('100'),
+          toWei('100'),
+          toWei('100'),
           true
         )
       })
@@ -272,7 +273,7 @@ module.exports = function(accounts) {
         const _wallets = [wallets[1], wallets[2], wallets[3]]
         let expectedValidatorId = 1
         for (const wallet of _wallets) {
-          await doStake(wallet, { approveAmount: web3.utils.toWei('100'), stakeAmount: web3.utils.toWei('100') }).call(this)
+          await doStake(wallet, { approveAmount: toWei('100'), stakeAmount: toWei('100') }).call(this)
 
           const validatorId = await this.stakeManager.getValidatorId(wallet.getAddressString())
           assertBigNumberEquality(expectedValidatorId, validatorId)
@@ -284,14 +285,14 @@ module.exports = function(accounts) {
     describe('stake with heimdall fee', function() {
       before(freshDeploy)
 
-      testStake(
-        wallets[0].getChecksumAddressString(),
-        wallets[0].getPublicKeyString(),
-        web3.utils.toWei('200'),
-        web3.utils.toWei('150'),
-        1,
-        web3.utils.toWei('50')
-      )
+      testStake({
+        user: wallets[0].getChecksumAddressString(),
+        userPubkey: wallets[0].getPublicKeyString(),
+        amount: toWei('200'),
+        stakeAmount: toWei('150'),
+        validatorId: 1,
+        fee: toWei('50')
+      })
     })
 
     describe('when Alice stakes, change signer and stakes with old signer', function() {
@@ -314,6 +315,33 @@ module.exports = function(accounts) {
         await expectRevert(doStake(wallets[3], { signer: AliceWallet.getPublicKeyString() }).call(this), 'Invalid signer')
       })
     })
+
+    describe('minimum deposit', function() {
+      const MinBidFraction = '1000' // 10%
+      const CorrectDeposit = toWei('100.1')
+      before(freshDeploy)
+      before(doStake(wallets[1], { aproveAmount: toWei('1001'), stakeAmount: toWei('1000') }))
+      before(async function() {
+        await this.stakeManager.setMinBidStakeFraction(MinBidFraction)
+      })
+
+      testStakeRevert(
+        wallets[2].getChecksumAddressString(),
+        wallets[2].getPublicKeyString(),
+        toWei('100'),
+        toWei('1'),
+        true
+      )
+
+      testStake({
+        user: wallets[2].getChecksumAddressString(),
+        userPubkey: wallets[2].getPublicKeyString(),
+        amount: toWei('200'),
+        stakeAmount: CorrectDeposit,
+        validatorId: '2',
+        totalStake: new BN(toWei('1000')).add(new BN(CorrectDeposit))
+      })
+    })
   })
 
   describe('unstake', function() {
@@ -454,7 +482,7 @@ module.exports = function(accounts) {
       })
 
       it('when unstakes during auction', async function() {
-        const amount = web3.utils.toWei('1200')
+        const amount = toWei('1200')
         const auctionUser = wallets[4].getAddressString()
         await this.stakeToken.mint(auctionUser, amount)
 
@@ -580,7 +608,7 @@ module.exports = function(accounts) {
       const Alice = wallets[2]
       const Bob = wallets[3]
       const Eve = wallets[4]
-      const stakeAmount = web3.utils.toWei('100')
+      const stakeAmount = toWei('100')
 
       before('Alice stake', doStake(Alice, { noMinting: true, stakeAmount }))
       before('Bob stake', doStake(Bob, { noMinting: true, stakeAmount }))
@@ -606,13 +634,13 @@ module.exports = function(accounts) {
         })
 
         it('must have correct reward', async function() {
-          assertBigNumberEquality(this.reward, web3.utils.toWei('3000'))
+          assertBigNumberEquality(this.reward, toWei('3000'))
         })
 
         it('must emit ClaimRewards', async function() {
           await expectEvent.inTransaction(this.receipt.tx, StakingInfo, 'ClaimRewards', {
             validatorId: this.validatorId,
-            amount: web3.utils.toWei('3000'),
+            amount: toWei('3000'),
             totalAmount: await this.stakeManager.totalRewardsLiquidated()
           })
         })
@@ -635,13 +663,13 @@ module.exports = function(accounts) {
         })
 
         it('must have correct reward', async function() {
-          assertBigNumberEquality(this.reward, web3.utils.toWei('3000'))
+          assertBigNumberEquality(this.reward, toWei('3000'))
         })
 
         it('must emit ClaimRewards', async function() {
           await expectEvent.inTransaction(this.receipt.tx, StakingInfo, 'ClaimRewards', {
             validatorId: this.validatorId,
-            amount: web3.utils.toWei('3000'),
+            amount: toWei('3000'),
             totalAmount: await this.stakeManager.totalRewardsLiquidated()
           })
         })
@@ -666,21 +694,21 @@ module.exports = function(accounts) {
         it('Eve must have correct rewards', async function() {
           const validatorId = await this.stakeManager.getValidatorId(Eve.getAddressString())
           this.reward = await this.stakeManager.validatorReward(validatorId)
-          assertBigNumberEquality(this.reward, web3.utils.toWei('12000'))
+          assertBigNumberEquality(this.reward, toWei('12000'))
         })
       })
     })
   })
 
   describe('restake', function() {
-    const initialStake = web3.utils.toWei('1000')
+    const initialStake = toWei('1000')
     const initialStakers = [wallets[0], wallets[1]]
 
     function doDeploy(acceptDelegation) {
       return async function() {
         await prepareForTest(8, 8).call(this)
 
-        const checkpointReward = new BN(web3.utils.toWei('10000'))
+        const checkpointReward = new BN(toWei('10000'))
 
         await this.governance.update(
           this.stakeManager.address,
@@ -710,7 +738,7 @@ module.exports = function(accounts) {
         this.validatorReward = checkpointReward.mul(new BN(100 - proposerBonus)).div(new BN(100)).mul(new BN(auctionPeriod - currentEpoch))
         this.validatorId = '1'
         this.user = initialStakers[0].getAddressString()
-        this.amount = web3.utils.toWei('100')
+        this.amount = toWei('100')
 
         await this.stakeToken.mint(this.user, this.amount)
         await this.stakeToken.approve(this.stakeManager.address, this.amount, {