Merge pull request #438 from keep-network/remove-funder-bond

Remove funder bond

We removed revokeFunderBond, returnFunderBond and getFunderBondAmount
functions as we won't require funder to put up a bond. The funder will need to
send a fee for opening a new keep which will be forwarded to the keep factory.

Author: Shadowfiend

implementation/contracts/deposit/DepositFunding.sol

@@ -74,26 +74,6 @@ library DepositFunding {
         return true;
     }
 
-    /// @notice     Transfers the funders bond to the signers if the funder never funds
-    /// @dev        Called only by notifyFundingTimeout
-    function revokeFunderBond(DepositUtils.Deposit storage _d) internal {
-        if (address(this).balance >= TBTCConstants.getFunderBondAmount()) {
-            _d.pushFundsToKeepGroup(TBTCConstants.getFunderBondAmount());
-        } else if (address(this).balance > 0) {
-            _d.pushFundsToKeepGroup(address(this).balance);
-        }
-    }
-
-    /// @notice     Returns the funder's bond plus a payment at contract teardown
-    /// @dev        Returns the balance if insufficient. Always call this before distributing signer payments
-    function returnFunderBond(DepositUtils.Deposit storage _d) internal {
-        if (address(this).balance >= TBTCConstants.getFunderBondAmount()) {
-            _d.depositOwner().transfer(TBTCConstants.getFunderBondAmount());
-        } else if (address(this).balance > 0) {
-            _d.depositOwner().transfer(address(this).balance);
-        }
-    }
-
     /// @notice     slashes the signers partially for committing fraud before funding occurs
     /// @dev        called only by notifyFraudFundingTimeout
     function partiallySlashForFraudInFunding(DepositUtils.Deposit storage _d) internal {
@@ -122,7 +102,6 @@ library DepositFunding {
         _d.setFailedSetup();
         _d.logSetupFailed();
 
-        returnFunderBond(_d);
         fundingTeardown(_d);
     }
 
@@ -159,7 +138,6 @@ library DepositFunding {
         _d.setFailedSetup();
         _d.logSetupFailed();
 
-        revokeFunderBond(_d);
         fundingTeardown(_d);
     }
 
@@ -197,7 +175,6 @@ library DepositFunding {
             /* NB: This is reuse of the variable */
             _d.fundingProofTimerStart = block.timestamp;
             _d.setFraudAwaitingBTCFundingProof();
-            returnFunderBond(_d);
         }
     }
 
@@ -297,13 +274,6 @@ library DepositFunding {
 
         require(_d.inAwaitingBTCFundingProof(), "Not awaiting funding");
 
-        // Design decision:
-        // We COULD revoke the funder bond here if the funding proof timeout has elapsed
-        // HOWEVER, that would only create a situation where the funder loses eerything
-        // It would be a large punishment for a small crime (being slightly late)
-        // So if the funder manages to call this before anyone notifies of timeout
-        // We let them have a freebie
-
         bytes8 _valueBytes;
         bytes memory  _utxoOutpoint;
 
@@ -327,8 +297,6 @@ library DepositFunding {
         _d.setActive();
         _d.logFunded();
 
-        returnFunderBond(_d);
-
         return true;
     }
 }

implementation/contracts/deposit/TBTCConstants.sol

@@ -22,7 +22,6 @@ library TBTCConstants {
     uint256 public constant FUNDING_PROOF_TIMEOUT = 3 * 60 * 60; // seconds
     uint256 public constant FORMATION_TIMEOUT = 3 * 60 * 60; // seconds
     uint256 public constant FRAUD_FUNDING_PROOF_TIMEOUT = 3 * 60 * 60; // seconds
-    uint256 public constant FUNDER_BOND_AMOUNT_WEI = 10 ** 5; // wei
 
     // Liquidation Flow
     uint256 public constant COURTESY_CALL_DURATION = 6 * 60 * 60; // seconds
@@ -45,7 +44,6 @@ library TBTCConstants {
     function getFundingTimeout() public pure returns (uint256) { return FUNDING_PROOF_TIMEOUT; }
     function getSigningGroupFormationTimeout() public pure returns (uint256) { return FORMATION_TIMEOUT; }
     function getFraudFundingTimeout() public pure returns (uint256) { return FRAUD_FUNDING_PROOF_TIMEOUT; }
-    function getFunderBondAmount() public pure returns (uint256) { return FUNDER_BOND_AMOUNT_WEI; }
 
     function getCourtesyCallTimeout() public pure returns (uint256) { return COURTESY_CALL_DURATION; }
     function getAuctionDuration() public pure returns (uint256) { return AUCTION_DURATION; }

implementation/test/DepositFraudTest.js

@@ -1,5 +1,9 @@
 import expectThrow from './helpers/expectThrow'
 import deployTestDeposit from './helpers/deployTestDeposit'
+import {
+  createSnapshot,
+  restoreSnapshot,
+} from './helpers/snapshot'
 
 import BN from 'bn.js'
 import utils from './utils'
@@ -33,7 +37,6 @@ const _signerPubkeyX = '0xd4aee75e57179f7cd18adcbaa7e2fca4ff7b1b446df88bf0b4398e
 const _signerPubkeyY = '0xe8bfb23428a4efecb3ebdc636139de9a568ed427fff20d28baa33ed48e9c44e1'
 const _merkleProof = '0x886f7da48f4ccfe49283c678dedb376c89853ba46d9a297fe39e8dd557d1f8deb0fb1a28c03f71b267f3a33459b2566975b1653a1238947ed05edca17ef64181b1f09d858a6e25bae4b0e245993d4ea77facba8ed0371bb9b8a6724475bcdc9edf9ead30b61cf6714758b7c93d1b725f86c2a66a07dd291ef566eaa5a59516823d57fd50557f1d938cc2fb61fe0e1acee6f9cb618a9210688a2965c52feabee66d660a5e7f158e363dc464fca2bb1cc856173366d5d20b5cd513a3aab8ebc5be2bd196b783b8773af2472abcea3e32e97938283f7b454769aa1c064c311c3342a755029ee338664999bd8d432080eafae3ca86b52ad2e321e9e634a46c1bd0d174e38bcd4c59a0f0a78c5906c015ef4daf6beb0500a59f4cae00cd46069ce60db2182e74561028e4462f59f639c89b8e254602d6ad9c212b7c2af5db9275e48c467539c6af678d6f09214182df848bd79a06df706f7c3fddfdd95e6f27326c6217ee446543a443f82b711f48c173a769ae8d1e92a986bc76fca732f088bbe049'
 
-
 contract('DepositFraud', (accounts) => {
   let tbtcConstants
   let mockRelay
@@ -138,24 +141,6 @@ contract('DepositFraud', (accounts) => {
         'Signature is not fraudulent'
       )
     })
-
-    it('returns the funder bond if the timer has not elapsed', async () => {
-      const funderBondAmount = new BN('10').pow(new BN('5'))
-      const blockNumber = await web3.eth.getBlock('latest').number
-      await testDeposit.send(funderBondAmount, { from: beneficiary })
-      const initialBalance = await web3.eth.getBalance(beneficiary)
-
-      await ecdsaKeepStub.setBondAmount(funderBondAmount)
-      await testDeposit.setFundingProofTimerStart(fundingProofTimerStart * 6)
-      await testDeposit.provideFundingECDSAFraudProof(0, utils.bytes32zero, utils.bytes32zero, utils.bytes32zero, '0x00')
-
-      const finalBalance = await web3.eth.getBalance(beneficiary)
-      const eventList = await tbtcSystemStub.getPastEvents('FraudDuringSetup', { fromBlock: blockNumber, toBlock: 'latest' })
-      const balanceCheck = new BN(initialBalance).add(funderBondAmount)
-
-      assert.equal(eventList.length, 1)
-      expect(finalBalance, 'funder should be included in final result').to.eq.BN(balanceCheck)
-    })
   })
 
   describe('notifyFraudFundingTimeout', async () => {
@@ -300,11 +285,19 @@ contract('DepositFraud', (accounts) => {
     })
   })
 
-
   describe('provideECDSAFraudProof', async () => {
-    beforeEach(async () => {
+    before(async () => {
       await testDeposit.setState(utils.states.ACTIVE)
       await ecdsaKeepStub.send(1000000, { from: accounts[0] })
+      await ecdsaKeepStub.setSuccess(true)
+    })
+
+    beforeEach(async () => {
+      await createSnapshot()
+    })
+
+    afterEach(async () => {
+      await restoreSnapshot()
     })
 
     it('executes', async () => {

implementation/test/DepositFundingTest.js

@@ -213,21 +213,6 @@ contract('DepositFunding', (accounts) => {
         'Signing group formation timeout not yet elapsed'
       )
     })
-
-    it('returns funder bond', async () => {
-      await testDeposit.send(funderBondAmount, { from: beneficiary })
-
-      const initialBalance = await web3.eth.getBalance(beneficiary)
-
-      await testDeposit.setSigningGroupRequestedAt(fundingProofTimerStart)
-      await ecdsaKeepStub.setBondAmount(funderBondAmount)
-
-      await testDeposit.notifySignerSetupFailure()
-
-      const balance = await web3.eth.getBalance(beneficiary)
-      const balanceCheck = new BN(initialBalance).add(funderBondAmount)
-      expect(balance, 'bond not returned to funder').to.eq.BN(balanceCheck)
-    })
   })
 
   describe('retrieveSignerPubkey', async () => {
@@ -333,15 +318,6 @@ contract('DepositFunding', (accounts) => {
         'Funding timeout has not elapsed'
       )
     })
-
-    it('distributes the funder bond to the keep group', async () => {
-      await testDeposit.setFundingProofTimerStart(fundingProofTimerStart)
-      await testDeposit.send(funderBondAmount, { from: beneficiary })
-      await testDeposit.notifyFundingTimeout()
-
-      const keepBalance = await web3.eth.getBalance(ecdsaKeepStub.address)
-      assert.equal(keepBalance, new BN(funderBondAmount), 'funder bond not distributed properly')
-    })
   })
 
   describe('provideBTCFundingProof', async () => {
@@ -393,18 +369,5 @@ contract('DepositFunding', (accounts) => {
         'Not awaiting funding'
       )
     })
-
-    it('returns funder bonds', async () => {
-      await testDeposit.send(funderBondAmount, { from: beneficiary })
-
-      const initialBalance = await web3.eth.getBalance(beneficiary)
-
-      await testDeposit.provideBTCFundingProof(_version, _txInputVector, _txOutputVector, _txLocktime, _fundingOutputIndex, _merkleProof, _txIndexInBlock, _bitcoinHeaders)
-
-      const actualBalance = await web3.eth.getBalance(beneficiary)
-      const expectedBalance = new BN(initialBalance).add(funderBondAmount)
-
-      assert.equal(actualBalance, expectedBalance, 'funder bond not correctly returned')
-    })
   })
 })

implementation/test/contracts/deposit/TestTBTCConstants.sol

@@ -22,7 +22,6 @@ library TestTBTCConstants {
     uint256 public constant FUNDING_PROOF_TIMEOUT = 3 * 60 * 60; // seconds
     uint256 public constant FORMATION_TIMEOUT = 3 * 60 * 60; // seconds
     uint256 public constant FRAUD_FUNDING_PROOF_TIMEOUT = 3 * 60 * 60; // seconds
-    uint256 public constant FUNDER_BOND_AMOUNT_WEI = 10 ** 5; // wei
 
     // Liquidation Flow
     uint256 public constant COURTESY_CALL_DURATION = 6 * 60 * 60; // seconds
@@ -44,7 +43,6 @@ library TestTBTCConstants {
     function getFundingTimeout() public pure returns (uint256) { return FUNDING_PROOF_TIMEOUT; }
     function getSigningGroupFormationTimeout() public pure returns (uint256) { return FORMATION_TIMEOUT; }
     function getFraudFundingTimeout() public pure returns (uint256) { return FRAUD_FUNDING_PROOF_TIMEOUT; }
-    function getFunderBondAmount() public pure returns (uint256) { return FUNDER_BOND_AMOUNT_WEI; }
 
     function getCourtesyCallTimeout() public pure returns (uint256) { return COURTESY_CALL_DURATION; }
     function getAuctionDuration() public pure returns (uint256) { return AUCTION_DURATION; }