[ETHEREUM-CONTRACTS] emit Pseudo Transfer event on flow create/delete and units changing from/to 0 (#2114)

d10r · hellwolf · web-flow · commit a99691746b6c · 2025-10-29T11:54:29.000+02:00
* emit Transfer event on flow create/delete and units changing from/to 0 * don't emit Approval event on transferFrom, refs #2115 * updated CHANGELOG * bumped version to 1.14.0 --------- Co-authored-by: Miao ZhiCheng <miao@superfluid.finance>
diff --git a/packages/automation-contracts/autowrap/package.json b/packages/automation-contracts/autowrap/package.json
@@ -3,7 +3,7 @@
     "description": "Open contracts that allow upgrading underlying token to supertokens based on running stream",
     "version": "0.3.0",
     "devDependencies": {
-        "@superfluid-finance/ethereum-contracts": "^1.13.0",
+        "@superfluid-finance/ethereum-contracts": "^1.14.0",
         "@superfluid-finance/metadata": "^1.6.2"
     },
     "license": "MIT",
diff --git a/packages/automation-contracts/scheduler/package.json b/packages/automation-contracts/scheduler/package.json
@@ -3,7 +3,7 @@
     "description": "Open contracts that allow scheduling streams and vestings onchain",
     "version": "1.3.0",
     "devDependencies": {
-        "@superfluid-finance/ethereum-contracts": "^1.13.0",
+        "@superfluid-finance/ethereum-contracts": "^1.14.0",
         "@superfluid-finance/metadata": "^1.6.2"
     },
     "license": "MIT",
diff --git a/packages/ethereum-contracts/CHANGELOG.md b/packages/ethereum-contracts/CHANGELOG.md
@@ -3,7 +3,7 @@ All notable changes to the ethereum-contracts will be documented in this file.
 
 This project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
-## [UNRELEASED]
+## [v1.14.0]
 
 ### Added
 - GDA _autoconnect_ feature: now any account can connect pool members using `tryConnectPoolFor()` as long as they have less than 4 connection slots occupied for that Super Token. This allows for smoother onboarding of new users, allowing Apps to make sure tokens distributed via GDA immediately show up in user's wallets. Accounts can opt out of this by using `setConnectPermission()`, this is mainly supposed to be used by contracts.
@@ -15,6 +15,8 @@ This project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.htm
   - `GDAv1StorageWriter` contains functions for writing agreement data to the token contract. This can only be used by the GDA contract itself.
 - bump solc to "0.8.30".
 - Changed EVM target from `paris` to `shanghai` because now all networks with supported Superfluid deployment support it.
+- Emit ERC20 `Transfer` events (with amount 0) on CFA and GDA actions potentially leading to account balance changes. This shall help indexers to keep track of SuperToken holders and account balances.
+- Don't emit ERC20 `Approval` events on `transferFrom` operations. This is consistent with the OpenZeppelin ERC20 implementation from v5 onwards. Change effective only for SuperTokens using the latest logic.
 
 ### Fixed
 - `ISuperfluidPool`: `getClaimable` and `getClaimableNow` could previously return non-zero values for connected pools, which was inconsistent with what `claimAll` would actually do in this situation (claim nothing).
diff --git a/packages/ethereum-contracts/README.md b/packages/ethereum-contracts/README.md
@@ -35,7 +35,7 @@ If you're building a smart contract that uses Superfluid protocol, or even your
 ### Installation
 
 Prerequisites:
-- [node.js v18+](https://nodejs.org/en/download). The project recommends 22, and is tested with node 18,20,22.
+- [node.js v20+](https://nodejs.org/en/download). The project recommends 24, and is tested with node 20,22,24.
 - [yarn](https://classic.yarnpkg.com/en/docs/install)
 - [forge](https://book.getfoundry.sh/getting-started/installation)
 
@@ -305,7 +305,7 @@ If you want contribute to Superfluid protocol contracts instead of just interfac
 
 ### Setup Development Environment
 
-Prerequisites: You need node.js v18+ and yarn installed.
+Prerequisites: You need node.js v20+ and yarn installed.
 
 First, check out this repository and cd into it.
 ```sh
diff --git a/packages/ethereum-contracts/contracts/agreements/ConstantFlowAgreementV1.sol b/packages/ethereum-contracts/contracts/agreements/ConstantFlowAgreementV1.sol
@@ -453,6 +453,8 @@ contract ConstantFlowAgreementV1 is
                 ctx, currentContext);
         }
 
+        flowVars.token.emitPseudoTransfer(flowVars.sender, flowVars.receiver);
+
         _requireAvailableBalance(flowVars.token, flowVars.sender, currentContext);
     }
 
@@ -592,6 +594,8 @@ contract ConstantFlowAgreementV1 is
                     newCtx, currentContext);
             }
         }
+
+        flowVars.token.emitPseudoTransfer(flowVars.sender, flowVars.receiver);
     }
 
     /**************************************************************************
diff --git a/packages/ethereum-contracts/contracts/agreements/gdav1/GeneralDistributionAgreementV1.sol b/packages/ethereum-contracts/contracts/agreements/gdav1/GeneralDistributionAgreementV1.sol
@@ -801,6 +801,14 @@ contract GeneralDistributionAgreementV1 is AgreementBase, TokenMonad, IGeneralDi
         return true;
     }
 
+    function tokenEmitPseudoTransfer(ISuperfluidToken superToken, address from, address to) external {
+        if (superToken.isPool(this, msg.sender) == false) {
+            revert GDA_ONLY_SUPER_TOKEN_POOL();
+        }
+
+        superToken.emitPseudoTransfer(from, to);
+    }
+
     //////////////////////////////////////////////////////////////////////////////////////////////////////
     // TokenMonad interface
     //////////////////////////////////////////////////////////////////////////////////////////////////////
diff --git a/packages/ethereum-contracts/contracts/agreements/gdav1/SuperfluidPool.sol b/packages/ethereum-contracts/contracts/agreements/gdav1/SuperfluidPool.sol
@@ -453,6 +453,11 @@ contract SuperfluidPool is ISuperfluidPool, BeaconProxiable {
             _membersData[memberAddr] = _pdPoolMemberToMemberData(pdPoolMember, claimedValue);
             assert(GDA.appendIndexUpdateByPool(superToken, p, t));
         }
+
+        if ((oldUnits == 0 || newUnits == 0) && oldUnits != newUnits) {
+            GDA.tokenEmitPseudoTransfer(superToken, address(this), memberAddr);
+        }
+
         emit MemberUnitsUpdated(superToken, memberAddr, oldUnits, newUnits);
     }
 
diff --git a/packages/ethereum-contracts/contracts/interfaces/superfluid/ISuperfluidToken.sol b/packages/ethereum-contracts/contracts/interfaces/superfluid/ISuperfluidToken.sol
@@ -431,4 +431,11 @@ interface ISuperfluidToken {
         uint256 rewardAmount,
         uint256 bailoutAmount
     );
+
+    /**
+     * @dev Emit an ERC20.Transfer event with zero amount, helps indexers track token holders.
+     * @param from The address from which the transfer is happening
+     * @param to The address to which the transfer is happening
+     */
+    function emitPseudoTransfer(address from, address to) external;
 }
diff --git a/packages/ethereum-contracts/contracts/superfluid/SuperToken.sol b/packages/ethereum-contracts/contracts/superfluid/SuperToken.sol
@@ -360,7 +360,7 @@ contract SuperToken is
         if (spender != holder) {
             require(amount <= _allowances[holder][spender], "SuperToken: transfer amount exceeds allowance");
             // TODO: this triggers an `Approval` event, which shouldn't happen for transfers.
-            _approve(holder, spender, _allowances[holder][spender] - amount);
+            _approve(holder, spender, _allowances[holder][spender] - amount, false);
         }
 
         return true;
@@ -504,7 +504,21 @@ contract SuperToken is
      * - `account` cannot be the zero address.
      * - `spender` cannot be the zero address.
      */
-    function _approve(address account, address spender, uint256 amount)
+    function _approve(address owner, address spender, uint256 value) internal {
+        _approve(owner, spender, value, true);
+    }
+
+    /**
+     * @dev Variant of {_approve} with an optional flag to enable or disable the {Approval} event.
+     *
+     * By default (when calling {_approve}) the flag is set to true. On the other hand, approval changes made
+     * during the `transferFrom` operation set the flag to false.
+     *
+     * Note: In the OpenZeppelin implementation, from v5 onwards, {transferFrom} doesn't emit an {Approval} event.
+     * By adding this overloaded function and using it for {transferFrom}, we replicate that change,
+     * because it seems semantically more correct.
+     */
+    function _approve(address account, address spender, uint256 amount, bool emitEvent)
         internal
     {
         if (account == address(0)) {
@@ -515,7 +529,10 @@ contract SuperToken is
         }
 
         _allowances[account][spender] = amount;
-        emit Approval(account, spender, amount);
+
+        if (emitEvent) {
+            emit Approval(account, spender, amount);
+        }
     }
 
     /**
diff --git a/packages/ethereum-contracts/contracts/superfluid/SuperfluidToken.sol b/packages/ethereum-contracts/contracts/superfluid/SuperfluidToken.sol
@@ -376,6 +376,10 @@ abstract contract SuperfluidToken is ISuperfluidToken
         );
     }
 
+    function emitPseudoTransfer(address from, address to) external onlyAgreement {
+        emit IERC20.Transfer(from, to, 0);
+    }
+
     /**************************************************************************
     * Modifiers
     *************************************************************************/
diff --git a/packages/ethereum-contracts/contracts/utils/ERC1820Implementer.sol b/packages/ethereum-contracts/contracts/utils/ERC1820Implementer.sol
@@ -3,7 +3,6 @@ pragma solidity ^0.8.23;
 
 import { IERC1820Implementer } from "@openzeppelin-v5/contracts/interfaces/IERC1820Implementer.sol";
 
-
 // Copy of OpenZeppelin v4.9.6: https://github.com/OpenZeppelin/openzeppelin-contracts/blob/v4.9.6/
 /**
  * @dev Implementation of the {IERC1820Implementer} interface.
diff --git a/packages/ethereum-contracts/package.json b/packages/ethereum-contracts/package.json
@@ -1,7 +1,7 @@
 {
     "name": "@superfluid-finance/ethereum-contracts",
     "description": " Ethereum contracts implementation for the Superfluid Protocol",
-    "version": "1.13.0",
+    "version": "1.14.0",
     "dependencies": {
         "@decentral.ee/web3-helpers": "0.5.3",
         "@nomiclabs/hardhat-ethers": "2.2.3",
diff --git a/packages/ethereum-contracts/test/contracts/superfluid/ERC20.behavior.ts b/packages/ethereum-contracts/test/contracts/superfluid/ERC20.behavior.ts
@@ -132,23 +132,6 @@ export function shouldBehaveLikeERC20(
                                 .to.emit(this.token, "Transfer")
                                 .withArgs(tokenOwner, to, amount);
                         });
-
-                        it("emits an approval event", async function () {
-                            await expect(
-                                this.token
-                                    .connect(spenderSigner)
-                                    .transferFrom(tokenOwner, to, amount)
-                            )
-                                .to.emit(this.token, "Approval")
-                                .withArgs(
-                                    tokenOwner,
-                                    spender,
-                                    await this.token.allowance(
-                                        tokenOwner,
-                                        spender
-                                    )
-                                );
-                        });
                     });
 
                     describe("when the token owner does not have enough balance", function () {
diff --git a/packages/ethereum-contracts/test/foundry/superfluid/SuperToken.t.sol b/packages/ethereum-contracts/test/foundry/superfluid/SuperToken.t.sol
@@ -1,18 +1,23 @@
 // SPDX-License-Identifier: AGPLv3
 pragma solidity ^0.8.23;
 
-import { Test } from "forge-std/Test.sol";
+import { Test, console } from "forge-std/Test.sol";
 import { UUPSProxy } from "../../../contracts/upgradability/UUPSProxy.sol";
 import { UUPSProxiable } from "../../../contracts/upgradability/UUPSProxiable.sol";
-import { IERC20, ISuperToken, SuperToken }
+import { IERC20, ISuperToken, ISuperfluidPool, PoolConfig }
+    from "../../../contracts/interfaces/superfluid/ISuperfluid.sol";
+import { SuperToken }
     from "../../../contracts/superfluid/SuperToken.sol";
 import { PoolAdminNFT, IPoolAdminNFT } from "../../../contracts/agreements/gdav1/PoolAdminNFT.sol";
 import { FoundrySuperfluidTester } from "../FoundrySuperfluidTester.t.sol";
 import { TestToken } from "../../../contracts/utils/TestToken.sol";
 import { TokenDeployerLibrary } from "../../../contracts/utils/SuperfluidFrameworkDeploymentSteps.t.sol";
+import { SuperTokenV1Library } from "../../../contracts/apps/SuperTokenV1Library.sol";
 
 contract SuperTokenIntegrationTest is FoundrySuperfluidTester {
-    constructor() FoundrySuperfluidTester(0) { }
+    using SuperTokenV1Library for ISuperToken;
+
+    constructor() FoundrySuperfluidTester(1) { }
 
     function setUp() public override {
         super.setUp();
@@ -254,4 +259,54 @@ contract SuperTokenIntegrationTest is FoundrySuperfluidTester {
         assertEq(localSuperToken.nonces(permitSigner), 1, "Nonce should be incremented");
         assertEq(localSuperToken.allowance(permitSigner, spender), amount, "Allowance should be set");
     }
+
+    // Verify zero Transfer events being emitted by CFA and GDA actions
+    function testEmitPseudoTransferEvent() public {
+        vm.startPrank(admin);
+
+        // case 1: create flow
+        vm.expectEmit(address(superToken));
+        emit IERC20.Transfer(admin, alice, 0);
+        superToken.createFlow(alice, 1);
+
+        // case 2: delete flow
+        vm.expectEmit(address(superToken));
+        emit IERC20.Transfer(admin, alice, 0);
+        superToken.deleteFlow(admin, alice);
+
+        // create a pool for the next tests
+        ISuperfluidPool pool = superToken.createPool(
+            admin,
+            PoolConfig({
+                transferabilityForUnitsOwner: true,
+                distributionFromAnyAddress: true
+            })
+        );
+
+        // case 3: assign pool units
+        vm.expectEmit(address(superToken));
+        emit IERC20.Transfer(address(pool), alice, 0);
+        pool.updateMemberUnits(alice, 1);
+
+        vm.stopPrank();
+
+        // case 4: test pool token transfer
+        vm.startPrank(alice);
+        // This emits 2 Transfer events, because the sender's units toggle to 0 and the receiver units from 0
+        vm.expectEmit(address(superToken));
+        emit IERC20.Transfer(address(pool), alice, 0);
+        vm.expectEmit(address(superToken));
+        emit IERC20.Transfer(address(pool), bob, 0);
+        IERC20(pool).transfer(bob, 1);
+
+        vm.stopPrank();
+
+        // case 5: remove pool units
+        vm.startPrank(admin);
+        vm.expectEmit(address(superToken));
+        emit IERC20.Transfer(address(pool), bob, 0);
+        pool.updateMemberUnits(bob, 0);
+
+        vm.stopPrank();
+    }
 }
diff --git a/packages/hot-fuzz/package.json b/packages/hot-fuzz/package.json
@@ -7,13 +7,13 @@
     },
     "bugs": "https://github.com/superfluid-finance/protocol-monorepo/issues",
     "devDependencies": {
-        "@superfluid-finance/ethereum-contracts": "^1.13.0"
+        "@superfluid-finance/ethereum-contracts": "^1.14.0"
     },
     "homepage": "https://github.com/superfluid-finance/protocol-monorepo#readme",
     "license": "AGPL-3.0",
     "main": "index.js",
     "peerDependencies": {
-        "@superfluid-finance/ethereum-contracts": "1.13.0"
+        "@superfluid-finance/ethereum-contracts": "1.14.0"
     },
     "repository": {
         "type": "git",
diff --git a/packages/js-sdk/package.json b/packages/js-sdk/package.json
@@ -13,7 +13,7 @@
         "node-fetch": "2.7.0"
     },
     "devDependencies": {
-        "@superfluid-finance/ethereum-contracts": "^1.13.0",
+        "@superfluid-finance/ethereum-contracts": "^1.14.0",
         "chai-as-promised": "^8.0.0",
         "webpack": "^5.94.0",
         "webpack-bundle-analyzer": "^4.10.2",
diff --git a/packages/sdk-core/package.json b/packages/sdk-core/package.json
@@ -4,7 +4,7 @@
     "version": "0.9.0",
     "bugs": "https://github.com/superfluid-finance/protocol-monorepo/issues",
     "dependencies": {
-        "@superfluid-finance/ethereum-contracts": "1.13.0",
+        "@superfluid-finance/ethereum-contracts": "1.14.0",
         "@superfluid-finance/metadata": "^1.6.2",
         "graphql-request": "6.1.0",
         "lodash": "4.17.21",

Original file line number	Diff line number	Diff line change
`@@ -453,6 +453,8 @@ contract ConstantFlowAgreementV1 is`
`453`	`453`	`ctx, currentContext);`
`454`	`454`	`}`
`455`	`455`
	`456`	`+ flowVars.token.emitPseudoTransfer(flowVars.sender, flowVars.receiver);`
	`457`	`+`
`456`	`458`	`_requireAvailableBalance(flowVars.token, flowVars.sender, currentContext);`
`457`	`459`	`}`
`458`	`460`
`@@ -592,6 +594,8 @@ contract ConstantFlowAgreementV1 is`
`592`	`594`	`newCtx, currentContext);`
`593`	`595`	`}`
`594`	`596`	`}`
	`597`	`+`
	`598`	`+ flowVars.token.emitPseudoTransfer(flowVars.sender, flowVars.receiver);`
`595`	`599`	`}`
`596`	`600`
`597`	`601`	`/**************************************************************************`
Original file line number	Diff line number	Diff line change
`@@ -453,6 +453,11 @@ contract SuperfluidPool is ISuperfluidPool, BeaconProxiable {`
`453`	`453`	`_membersData[memberAddr] = _pdPoolMemberToMemberData(pdPoolMember, claimedValue);`
`454`	`454`	`assert(GDA.appendIndexUpdateByPool(superToken, p, t));`
`455`	`455`	`}`
	`456`	`+`
	`457`	`+ if ((oldUnits == 0 \|\| newUnits == 0) && oldUnits != newUnits) {`
	`458`	`+ GDA.tokenEmitPseudoTransfer(superToken, address(this), memberAddr);`
	`459`	`+ }`
	`460`	`+`
`456`	`461`	`emit MemberUnitsUpdated(superToken, memberAddr, oldUnits, newUnits);`
`457`	`462`	`}`
`458`	`463`