feat: remove duplicate isNative check

Author: ChefMist

snapshots/BinPositionManagerHelperTest.json

@@ -1,8 +1,8 @@
 {
-  "BinPositionManagerHelper size": "8610",
-  "test_addLiquidities_existingPool": "1043905",
-  "test_addLiquidities_existingPool_bobReceiver": "1043905",
-  "test_addLiquidities_existingPool_nativeToken": "962157",
-  "test_addLiquidities_newPool": "1167962",
-  "test_addLiquidities_newPool_WithPermit": "1227012"
+  "BinPositionManagerHelper size": "8601",
+  "test_addLiquidities_existingPool": "1043871",
+  "test_addLiquidities_existingPool_bobReceiver": "1043871",
+  "test_addLiquidities_existingPool_nativeToken": "962140",
+  "test_addLiquidities_newPool": "1167928",
+  "test_addLiquidities_newPool_WithPermit": "1226978"
 }

src/pool-bin/BinPositionManagerHelper.sol

@@ -128,12 +128,11 @@ contract BinPositionManagerHelper is Multicall, Permit2Forwarder, ReentrancyLock
         try binPoolManager.initialize(key, activeId) {} catch {}
     }
 
-    /// @dev Approve the bin position manager to spend the currency
+    /// @notice Approve the bin position manager to spend the currency
+    /// @dev assume currency is not native
     function _approveBinPm(Currency _currency, uint160 _amount) internal {
-        if (!_currency.isNative()) {
-            IERC20(Currency.unwrap(_currency)).approve(address(permit2), _amount);
-            permit2.approve(Currency.unwrap(_currency), address(binPositionManager), _amount, uint48(block.timestamp));
-        }
+        IERC20(Currency.unwrap(_currency)).approve(address(permit2), _amount);
+        permit2.approve(Currency.unwrap(_currency), address(binPositionManager), _amount, uint48(block.timestamp));
     }
 
     function _getAddLiquidityParam(bytes calldata payload)

test/pool-bin/BinPositionManagerHelper.t.sol

@@ -61,7 +61,6 @@ contract BinPositionManagerHelperTest is
 
     bytes32 poolParam;
     address alice = makeAddr("alice");
-    address bob = makeAddr("bob");
     uint24 activeId = 2 ** 23; // where token0 and token1 price is the same
 
     function setUp() public {
@@ -164,8 +163,10 @@ contract BinPositionManagerHelperTest is
         assertEq(token1.balanceOf(alice), 1 ether); // initial 4 ether, then minus 3 ether added
     }
 
-    /// @dev mint to bob instead 
+    /// @dev mint to bob instead
     function test_addLiquidities_existingPool_bobReceiver() public {
+        address bob = makeAddr("bob");
+
         // before
         token0.mint(alice, 4 ether);
         token1.mint(alice, 4 ether);