Update docs

test/helpers/random.js

@@ -0,0 +1,19 @@
+const { ethers } = require('hardhat');
+
+const generators = {
+  address: () => ethers.Wallet.createRandom().address,
+  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)),
+};
+
+generators.address.zero = ethers.ZeroAddress;
+generators.bytes32.zero = ethers.ZeroHash;
+generators.uint256.zero = 0n;
+generators.int256.zero = 0n;
+generators.hexBytes.zero = '0x';
+
+module.exports = {
+  generators,
+};