Add support for more types in Arrays.sol

.changeset/rare-shirts-unite.md

@@ -0,0 +1,5 @@
+---
+'openzeppelin-solidity': minor
+---
+
+`Arrays`: Add `unsafeSetLength` for `bytes[]` and `string[]`.

contracts/utils/Arrays.sol

@@ -479,4 +479,26 @@ library Arrays {
             sstore(array.slot, len)
         }
     }
+
+    /**
+     * @dev Helper to set the length of a dynamic array. Directly writing to `.length` is forbidden.
+     *
+     * WARNING: this does not clear elements if length is reduced, of initialize elements if length is increased.
+     */
+    function unsafeSetLength(bytes[] storage array, uint256 len) internal {
+        assembly ("memory-safe") {
+            sstore(array.slot, len)
+        }
+    }
+
+    /**
+     * @dev Helper to set the length of a dynamic array. Directly writing to `.length` is forbidden.
+     *
+     * WARNING: this does not clear elements if length is reduced, of initialize elements if length is increased.
+     */
+    function unsafeSetLength(string[] storage array, uint256 len) internal {
+        assembly ("memory-safe") {
+            sstore(array.slot, len)
+        }
+    }
 }

scripts/generate/templates/Arrays.js

@@ -378,6 +378,9 @@ module.exports = format(
       TYPES.map(unsafeAccessStorage),
       TYPES.map(unsafeAccessMemory),
       TYPES.map(unsafeSetLength),
+      // arrays of non-value types
+      unsafeSetLength('bytes'),
+      unsafeSetLength('string'),
     ),
   ).trimEnd(),
   '}',

test/helpers/random.js

@@ -5,14 +5,19 @@ const generators = {
   bytes32: () => ethers.hexlify(ethers.randomBytes(32)),
   uint256: () => ethers.toBigInt(ethers.randomBytes(32)),
   int256: () => ethers.toBigInt(ethers.randomBytes(32)) + ethers.MinInt256,
-  hexBytes: length => ethers.hexlify(ethers.randomBytes(length)),
+  bytes: (length = 32) => ethers.hexlify(ethers.randomBytes(length)),
+  string: () => ethers.uuidV4(ethers.randomBytes(32)),
 };
 
 generators.address.zero = ethers.ZeroAddress;
 generators.bytes32.zero = ethers.ZeroHash;
 generators.uint256.zero = 0n;
 generators.int256.zero = 0n;
-generators.hexBytes.zero = '0x';
+generators.bytes.zero = '0x';
+generators.string.zero = '';
+
+// alias hexBytes -> bytes
+generators.hexBytes = generators.bytes;
 
 module.exports = {
   generators,