fix: re-add fail(string) (#697)

Fixes #583.

Co-authored-by: zerosnacks <[email protected]>

Author: DaniPopes

src/StdAssertions.sol

@@ -33,21 +33,28 @@ abstract contract StdAssertions {
     event log_named_array(string key, int256[] val);
     event log_named_array(string key, address[] val);
 
+    bytes32 private constant FAILED_SLOT = bytes32("failed");
+
     bool private _failed;
 
     function failed() public view returns (bool) {
         if (_failed) {
-            return _failed;
+            return true;
         } else {
-            return vm.load(address(vm), bytes32("failed")) != bytes32(0);
+            return vm.load(address(vm), FAILED_SLOT) != bytes32(0);
         }
     }
 
     function fail() internal virtual {
-        vm.store(address(vm), bytes32("failed"), bytes32(uint256(1)));
+        vm.store(address(vm), FAILED_SLOT, bytes32(uint256(1)));
         _failed = true;
     }
 
+    function fail(string memory message) internal virtual {
+        fail();
+        vm.assertTrue(false, message);
+    }
+
     function assertTrue(bool data) internal pure virtual {
         if (!data) {
             vm.assertTrue(data);