Add stubs for the rest of ERC20-related safe-functions

contracts/src/token/erc20/utils/safe_erc20.rs

@@ -128,4 +128,38 @@ impl SafeErc20 {
 
         Ok(())
     }
+
+    /// Increase the calling contract's allowance toward `spender` by `value`. If `token` returns no value,
+    /// non-reverting calls are assumed to be successful.
+    pub fn safe_increase_allowance(
+        &mut self,
+        token: Address,
+        spender: Address,
+        value: U256,
+    ) -> Result<(), Error> {
+        todo!()
+    }
+
+    /// Decrease the calling contract's allowance toward `spender` by `requestedDecrease`. If `token` returns no
+    /// value, non-reverting calls are assumed to be successful.
+    pub fn safe_decrease_allowance(
+        &mut self,
+        token: Address,
+        spender: Address,
+        requested_decrease: U256,
+    ) -> Result<(), Error> {
+        todo!()
+    }
+
+    /// Set the calling contract's allowance toward `spender` to `value`. If `token` returns no value,
+    /// non-reverting calls are assumed to be successful. Meant to be used with tokens that require the approval
+    /// to be set to zero before setting it to a non-zero value, such as USDT.
+    pub fn force_approve(
+        &mut self,
+        token: Address,
+        spender: Address,
+        value: U256,
+    ) -> Result<(), Error> {
+        todo!()
+    }
 }

examples/safe-erc20/tests/abi/mod.rs

@@ -6,6 +6,9 @@ sol!(
    contract SafeErc20 {
         function safeTransfer(address token, address to, uint256 value) external;
         function safeTransferFrom(address token, address from, address to, uint256 value) external;
+        function safeIncreaseAllowance(address token, address spender, uint256 value) external;
+        function safeDecreaseAllowance(address token, address spender, uint256 requestedDecrease) external;
+        function forceApprove(address token, address spender, uint256 value) external;
 
         error SafeErc20FailedOperation(address token);
         error SafeErc20FailedDecreaseAllowance(address spender, uint256 currentAllowance, uint256 requestedDecrease);