Add in owner fee to GNS for upgrade or deprecate

Author: davekay100

cli/commands/protocol/get.ts

@@ -41,6 +41,7 @@ export const gettersList = {
   // GNS
   'gns-minimum-signal': { contract: 'GNS', name: 'minimumVSignalStake' },
   'gns-bonding-curve': { contract: 'GNS', name: 'bondingCurve' },
+  'gns-deprecate-fee-percentage': { contract: 'GNS', name: 'changeFeePercentage' },
   // Token
   'token-governor': { contract: 'GraphToken', name: 'governor' },
   'token-supply': { contract: 'GraphToken', name: 'totalSupply' },

cli/commands/protocol/set.ts

@@ -43,6 +43,7 @@ export const settersList = {
   'rewards-issuance-rate': { contract: 'RewardsManager', name: 'setIssuanceRate' },
   // GNS
   'gns-minimum-signal': { contract: 'GNS', name: 'setMinimumVsignal' },
+  'gns-deprecate-fee-percentage': { contract: 'GNS', name: 'setChangeFeePercentage' },
   // Token
   'token-transfer-governor': { contract: 'GraphToken', name: 'transferOwnership' },
   'token-accept-governor': { contract: 'GraphToken', name: 'acceptOwnership' },

contracts/discovery/GNS.sol

@@ -33,16 +33,19 @@ contract GNS is Managed {
     // Equates to Connector weight on bancor formula to be CW = 1
     uint32 private constant defaultReserveRatio = 1000000;
 
+    // In parts per hundred
+    uint32 public changeFeePercentage = 50;
+
+    // Bonding curve formula
+    address public bondingCurve;
+
     // Amount of nSignal you get with your minimum vSignal stake
     uint256 private constant VSIGNAL_PER_MINIMUM_NSIGNAL = 1 ether;
 
     // Minimum amount of vSignal that must be staked to start the curve
     // Set to 10**18, as vSignal has 18 decimals
     uint256 public minimumVSignalStake = 10**18;
 
-    // Bonding curve formula
-    address public bondingCurve;
-
     // graphAccountID => subgraphNumber => subgraphDeploymentID
     // subgraphNumber = A number associated to a graph accounts deployed subgraph. This
     //                  is used to point to a subgraphID (graphAccountID + subgraphNumber)
@@ -203,6 +206,17 @@ contract GNS is Managed {
         emit ParameterUpdated("minimumVSignalStake");
     }
 
+    /**
+     * @dev Set the change fee percentage. This is used to prevent a subgraph owner to drain all
+     * the name curators tokens while upgrading or deprecating and is configurable in parts per hundred.
+     * @param _changeFeePercentage Change fee percentage
+     */
+    function setChangeFeePercentage(uint32 _changeFeePercentage) external onlyGovernor {
+        require(_changeFeePercentage <= 100, "Change fee must be 100 or less");
+        changeFeePercentage = _changeFeePercentage;
+        emit ParameterUpdated("changeFeePercentage");
+    }
+
     /**
      * @dev Allows a graph account to set a default name
      * @param _graphAccount Account that is setting their name
@@ -379,15 +393,13 @@ contract GNS is Managed {
             namePool.subgraphDeploymentID,
             vSignalOld
         );
+        uint256 ownerFee = _ownerFee(withdrawalFees, _graphAccount);
         namePool.vSignal = namePool.vSignal.sub(vSignalOld);
         // Update name signals deployment ID to match the subgraphs deployment ID
         namePool.subgraphDeploymentID = _newSubgraphDeploymentID;
 
         // nSignal stays constant, but vSignal can change here
-        uint256 vSignalNew = curation.mint(
-            namePool.subgraphDeploymentID,
-            (tokens + withdrawalFees)
-        );
+        uint256 vSignalNew = curation.mint(namePool.subgraphDeploymentID, (tokens + ownerFee));
         namePool.vSignal = vSignalNew;
         emit NameSignalUpgrade(
             _graphAccount,
@@ -463,12 +475,8 @@ contract GNS is Managed {
                 vSignal
             );
 
-            // Get the owner of the Name to reimburse the withdrawal fee
-            require(
-                graphToken().transferFrom(_graphAccount, address(this), withdrawalFees),
-                "GNS: Error reimbursing withdrawal fees"
-            );
-            namePool.withdrawableGRT = tokens + withdrawalFees;
+            uint256 ownerFee = _ownerFee(withdrawalFees, _graphAccount);
+            namePool.withdrawableGRT = tokens + ownerFee;
         }
         // Set the NameCurationPool fields to make it disabled
         namePool.disabled = true;
@@ -573,6 +581,22 @@ contract GNS is Managed {
         return (tokens, withdrawalFees);
     }
 
+    /**
+     * @dev Calculate fee that owner will have to cover for upgrading or deprecating
+     * @param _owner Subgraph owner
+     * @param _withdrawalFees Total withdrawal fee for changing subgraphs
+     * @return Amount the owner must pay by transferring GRT to the GNS
+     */
+    function _ownerFee(uint256 _withdrawalFees, address _owner) private returns (uint256) {
+        uint256 ownerFee = _withdrawalFees.mul(changeFeePercentage).div(100);
+        // Get the owner of the Name to reimburse the withdrawal fee
+        require(
+            graphToken().transferFrom(_owner, address(this), ownerFee),
+            "GNS: Error reimbursing withdrawal fees"
+        );
+        return ownerFee;
+    }
+
     /**
      * @dev Calculate nSignal to be returned for an amount of tokens
      * @param _graphAccount Subgraph owner

test/gns.test.ts

@@ -820,7 +820,6 @@ describe('GNS', () => {
       const newValue = toGRT('100')
       it('should set `minimumVSignalStake`', async function () {
         // Can set if allowed
-        const newValue = toGRT('100')
         await gns.connect(governor.signer).setMinimumVsignal(newValue)
         expect(await gns.minimumVSignalStake()).eq(newValue)
       })
@@ -902,6 +901,22 @@ describe('GNS', () => {
           // we compare 1:1 ratio. Its implied that vSignal is 1 as well (1:1:1)
           expect(tokensToDeposit).eq(nSignalCreated)
         }
+    describe('setDeprecateFeePercentage', function () {
+      const newValue = 10
+      it('should set `minimumVSignalStake`', async function () {
+        // Can set if allowed
+        await gns.connect(governor.signer).setDeprecateFeePercentage(newValue)
+        expect(await gns.deprecateFeePercentage()).eq(newValue)
+      })
+
+      it('reject set `minimumVSignalStake` if out of bounds', async function () {
+        const tx = gns.connect(governor.signer).setDeprecateFeePercentage(101)
+        await expect(tx).revertedWith('Deprecate fee must be 100 or less')
+      })
+
+      it('reject set `minimumVSignalStake` if not allowed', async function () {
+        const tx = gns.connect(me.signer).setDeprecateFeePercentage(newValue)
+        await expect(tx).revertedWith('Caller must be Controller governor')
       })
     })
   })