diff --git a/.gitignore b/.gitignore
index 85198aa..408b2b2 100644
--- a/.gitignore
+++ b/.gitignore
@@ -2,6 +2,9 @@
 cache/
 out/
 
+# OS file
+.DS_Store
+
 # Ignores development broadcast logs
 !/broadcast
 /broadcast/*/31337/
diff --git a/src/AssertWrapper.sol b/src/AssertWrapper.sol
index 45f00a2..23711b9 100644
--- a/src/AssertWrapper.sol
+++ b/src/AssertWrapper.sol
@@ -59,4 +59,34 @@ abstract contract AssertWrapper is AssertHelper {
     function t(bool a, string memory message) internal {
         assertWithMsg(a, message);
     }
+
+    function assertErrorsAllowed(bytes4 errorSelector, bytes4[] memory allowedErrors, string memory message) private {
+        bool allowed = false;
+        for (uint256 i = 0; i < allowedErrors.length; i++) {
+            if (errorSelector == allowedErrors[i]) {
+                allowed = true;
+            } else {
+                allowed = false;
+            }
+            if (!allowed) break;
+        }
+        t(allowed, message);
+    }
+
+    function assertErrorsAllowedMultiMsg(bytes4 errorSelector, bytes4[] memory allowedErrors, string[] memory message) private {
+        bool allowed = false;
+        uint256 errorIndex = 0;
+        for (uint256 i = 0; i < allowedErrors.length; i++) {
+            if (errorSelector == allowedErrors[i]) {
+                allowed = true;
+            } else {
+                allowed = false;
+            }
+            if (!allowed) {
+                errorIndex = i;
+                break;
+            }
+        }
+        t(allowed, message[errorIndex]);
+    }
 }