Enhanced integration & optimized testing

contracts/lib/utils/SafeTransferLib.sol

@@ -114,46 +114,4 @@ library SafeTransferLib {
 
         require(success, "TRANSFER_FAILED");
     }
-
-    function safeApprove(
-        ERC20 token,
-        address to,
-        uint256 amount
-    ) internal {
-        bool success;
-
-        assembly {
-            // We'll write our calldata to this slot below, but restore it later.
-            let memPointer := mload(0x40)
-
-            // Write the abi-encoded calldata into memory, beginning with the function selector.
-            mstore(
-                0,
-                0x095ea7b300000000000000000000000000000000000000000000000000000000
-            )
-            mstore(4, to) // Append the "to" argument.
-            mstore(36, amount) // Append the "amount" argument.
-
-            success := and(
-                // Set success to whether the call reverted, if not we check it either
-                // returned exactly 1 (can't just be non-zero data), or had no return data.
-                or(
-                    and(
-                        eq(mload(0), 1),
-                        gt(returndatasize(), 31)
-                    ),
-                    iszero(returndatasize())
-                ),
-                // We use 68 because that's the total length of our calldata (4 + 32 * 2)
-                // Counterintuitively, this call() must be positioned after the or() in the
-                // surrounding and() because and() evaluates its arguments from right to left.
-                call(gas(), token, 0, 0, 68, 0, 32)
-            )
-
-            mstore(0x60, 0) // Restore the zero slot to zero.
-            mstore(0x40, memPointer) // Restore the memPointer.
-        }
-
-        require(success, "APPROVE_FAILED");
-    }
 }