Do not emit Approval event when calling transferFrom (OpenZeppelin#4370)

Co-authored-by: Ernesto García <ernestognw@gmail.com> Co-authored-by: Francisco <fg@frang.io>
ernestognw · Jul 3, 2023 · abbbaef · abbbaef
1 parent f6cc3af
commit abbbaef
Show file tree

Hide file tree

Showing 4 changed files with 82 additions and 80 deletions.
diff --git a/contracts/mocks/token/ERC20ApprovalMock.sol b/contracts/mocks/token/ERC20ApprovalMock.sol
@@ -1,7 +1,7 @@
 // SPDX-License-Identifier: MIT
 pragma solidity ^0.8.19;
 
-import {ERC20} from "../../token/ERC20/ERC20.sol";
+import "../../token/ERC20/ERC20.sol";
 
 abstract contract ERC20ApprovalMock is ERC20 {
     function _approve(address owner, address spender, uint256 amount, bool) internal virtual override {

diff --git a/contracts/token/ERC20/ERC20.sol b/contracts/token/ERC20/ERC20.sol
@@ -314,8 +314,8 @@ abstract contract ERC20 is Context, IERC20, IERC20Metadata, IERC20Errors {
      * - `owner` cannot be the zero address.
      * - `spender` cannot be the zero address.
      */
-    function _approve(address owner, address spender, uint256 value) internal virtual {
-        _approve(owner, spender, value, true);
+    function _approve(address owner, address spender, uint256 amount) internal virtual {
+        _approve(owner, spender, amount, true);
     }
 
     /**
@@ -328,23 +328,23 @@ abstract contract ERC20 is Context, IERC20, IERC20Metadata, IERC20Errors {
      * Anyone who wishes to continue emitting `Approval` events on the`transferFrom` operation can force the flag to true
      * using the following override:
      * ```
-     * function _approve(address owner, address spender, uint256 value, bool) internal virtual override {
-     *     super._approve(owner, spender, value, true);
+     * function _approve(address owner, address spender, uint256 amount, bool) internal virtual override {
+     *     super._approve(owner, spender, amount, true);
      * }
      * ```
      *
      * Requirements are the same as {_approve}.
      */
-    function _approve(address owner, address spender, uint256 value, bool emitEvent) internal virtual {
+    function _approve(address owner, address spender, uint256 amount, bool emitEvent) internal virtual {
         if (owner == address(0)) {
             revert ERC20InvalidApprover(address(0));
         }
         if (spender == address(0)) {
             revert ERC20InvalidSpender(address(0));
         }
-        _allowances[owner][spender] = value;
+        _allowances[owner][spender] = amount;
         if (emitEvent) {
-            emit Approval(owner, spender, value);
+            emit Approval(owner, spender, amount);
         }
     }
 
@@ -363,7 +363,7 @@ abstract contract ERC20 is Context, IERC20, IERC20Metadata, IERC20Errors {
                 revert ERC20InsufficientAllowance(spender, currentAllowance, value);
             }
             unchecked {
-                _approve(owner, spender, currentAllowance - value, false);
+                _approve(owner, spender, currentAllowance - amount, false);
             }
         }
     }

diff --git a/test/token/ERC20/ERC20.behavior.js b/test/token/ERC20/ERC20.behavior.js
@@ -75,7 +75,7 @@ function shouldBehaveLikeERC20(initialSupply, accounts, opts = {}) {
 
             if (forcedApproval) {
               it('emits an approval event', async function () {
-                expectEvent(await this.token.transferFrom(tokenOwner, to, value, { from: spender }), 'Approval', {
+                expectEvent(await this.token.transferFrom(tokenOwner, to, amount, { from: spender }), 'Approval', {
                   owner: tokenOwner,
                   spender: spender,
                   value: await this.token.allowance(tokenOwner, spender),
@@ -84,7 +84,7 @@ function shouldBehaveLikeERC20(initialSupply, accounts, opts = {}) {
             } else {
               it('does not emit an approval event', async function () {
                 expectEvent.notEmitted(
-                  await this.token.transferFrom(tokenOwner, to, value, { from: spender }),
+                  await this.token.transferFrom(tokenOwner, to, amount, { from: spender }),
                   'Approval',
                 );
               });