From a373941217af337db86d0683aa19d87845097719 Mon Sep 17 00:00:00 2001
From: 0age <37939117+0age@users.noreply.github.com>
Date: Wed, 16 Oct 2024 22:20:50 -0700
Subject: [PATCH] use an efficiency lib fn

---
 src/lib/EfficiencyLib.sol | 6 ++++++
 src/lib/MetadataLib.sol   | 8 +++++---
 2 files changed, 11 insertions(+), 3 deletions(-)

diff --git a/src/lib/EfficiencyLib.sol b/src/lib/EfficiencyLib.sol
index fed20a7..80117f1 100644
--- a/src/lib/EfficiencyLib.sol
+++ b/src/lib/EfficiencyLib.sol
@@ -40,6 +40,12 @@ library EfficiencyLib {
         }
     }
 
+    function isNullAddress(address account) internal pure returns (bool isNull) {
+        assembly {
+            isNull := iszero(shl(96, account))
+        }
+    }
+
     function asUint256(bool a) internal pure returns (uint256 b) {
         assembly {
             b := a
diff --git a/src/lib/MetadataLib.sol b/src/lib/MetadataLib.sol
index 9183074..854a199 100644
--- a/src/lib/MetadataLib.sol
+++ b/src/lib/MetadataLib.sol
@@ -5,6 +5,7 @@ import { Lock } from "../types/Lock.sol";
 import { ResetPeriod } from "../types/ResetPeriod.sol";
 // TODO: add scope to metadata
 import { IdLib } from "./IdLib.sol";
+import { EfficiencyLib } from "./EfficiencyLib.sol";
 import { LibString } from "solady/utils/LibString.sol";
 import { MetadataReaderLib } from "solady/utils/MetadataReaderLib.sol";
 
@@ -13,13 +14,14 @@ library MetadataLib {
     using MetadataLib for string;
     using IdLib for Lock;
     using IdLib for ResetPeriod;
+    using EfficiencyLib for address;
     using LibString for uint256;
     using LibString for address;
     using MetadataReaderLib for address;
 
     function toURI(Lock memory lock, uint256 id) internal view returns (string memory uri) {
         string memory tokenAddress =
-            lock.token == address(0) ? "Native Token" : lock.token.toHexStringChecksummed();
+            lock.token.isNullAddress() ? "Native Token" : lock.token.toHexStringChecksummed();
         string memory allocator = lock.allocator.toHexStringChecksummed();
         string memory resetPeriod =
             string.concat(lock.resetPeriod.toSeconds().toString(), " seconds"); // TODO: return minutes / hours / days
@@ -76,7 +78,7 @@ library MetadataLib {
         returns (string memory symbol)
     {
         // NOTE: this will not take into account the correct symbol on many chains
-        if (token == address(0)) {
+        if (token.isNullAddress()) {
             return "ETH";
         }
 
@@ -91,7 +93,7 @@ library MetadataLib {
         view
         returns (string memory decimals)
     {
-        if (token == address(0)) {
+        if (token.isNullAddress()) {
             return "18";
         }
         return uint256(token.readDecimals()).toString();