From 18ff2242be09e13656603ce66f48905462fb3c75 Mon Sep 17 00:00:00 2001
From: tracy <25892474+traceurl@users.noreply.github.com>
Date: Tue, 27 Feb 2024 11:01:15 +0800
Subject: [PATCH] ERC20Helper compatible with non-standard ERC20

---
 contracts/helper/ERC20Helper.sol | 37 +++++++++++++++++++++++++++++---
 1 file changed, 34 insertions(+), 3 deletions(-)

diff --git a/contracts/helper/ERC20Helper.sol b/contracts/helper/ERC20Helper.sol
index 624ef65..42ba37e 100644
--- a/contracts/helper/ERC20Helper.sol
+++ b/contracts/helper/ERC20Helper.sol
@@ -16,6 +16,15 @@ interface IERC20ForCheck {
     function allowance(address owner, address spender) external view returns (uint256);
 }
 
+interface IOldERC20ForCheck {
+    function decimals() external view returns (uint);
+    function name() external view returns (bytes32);
+    function symbol() external view returns (bytes32);
+
+    function balanceOf(address account) external view returns (uint256);
+    function allowance(address owner, address spender) external view returns (uint256);
+}
+
 
 contract ERC20Helper {
     function isERC20(address token, address user, address spender) external view returns(bool isOk, string memory symbol, string memory name, uint decimals, uint256 balance, uint256 allownance) {
@@ -27,16 +36,38 @@ contract ERC20Helper {
             allownance = _allownance;
             isOk = true;
         } catch {
-            isOk = false;
+            try this.judgeOldERC20(token, user, spender) returns (bytes32 _symbol, bytes32 _name, uint _decimals, uint256 _balance, uint256 _allownance) {
+                symbol = bytes32ToString(_symbol);
+                name = bytes32ToString(_name);
+                decimals = _decimals;
+                balance = _balance;
+                allownance = _allownance;
+                isOk = true;
+            } catch {
+                isOk = false;
+            }   
         }      
     }
 
-   function judgeERC20(address token, address user, address spender) external view returns(string memory symbol, string memory name, uint decimals, uint256 balance, uint256 allownance) {
+    function judgeERC20(address token, address user, address spender) external view returns(string memory symbol, string memory name, uint decimals, uint256 balance, uint256 allownance) {
         name = IERC20ForCheck(token).name();
         symbol = IERC20ForCheck(token).symbol();
         decimals = IERC20ForCheck(token).decimals();
         
         balance = IERC20ForCheck(token).balanceOf(user);
         allownance = IERC20ForCheck(token).allowance(user,spender);
-   }
+    }
+
+    function judgeOldERC20(address token, address user, address spender) external view returns(bytes32 symbol, bytes32 name, uint decimals, uint256 balance, uint256 allownance) {
+        name = IOldERC20ForCheck(token).name();
+        symbol = IOldERC20ForCheck(token).symbol();
+        decimals = IOldERC20ForCheck(token).decimals();
+        
+        balance = IOldERC20ForCheck(token).balanceOf(user);
+        allownance = IOldERC20ForCheck(token).allowance(user,spender);
+    }
+
+    function bytes32ToString(bytes32 _bytes) public pure returns (string memory _string) {
+        _string = string(abi.encodePacked(_bytes));
+    }
 }
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