Add test for using salt in ERC20PermitHandler

lib/contracts/handlers/erc20-permit-handler.test.ts

@@ -4,7 +4,7 @@ import {
   setupTestPublicClient,
 } from '../../../test/setup-test-clients';
 import { mockAccount, testingUtils } from '../../../test/setup-tests';
-import { Token } from '../tokens';
+import { Token, TOKENS_SALT } from '../tokens';
 import { ERC20PERMIT_ABI } from '../abis/tokens-abis';
 import { ERC20PermitHandler } from './erc20-permit-handler';
 import {
@@ -66,4 +66,33 @@ describe('ERC20PermitHandler', () => {
     const txHash = await handler.approve(mockAccount, mockSpender, 1n);
     expect(isHash(txHash)).toBeTruthy();
   });
+
+  it('should use permit salt for tokens that have it', async () => {
+    // Using mainnet for this test since it has salt for pufETHwstE.
+    handler = new ERC20PermitHandler(Chain.Mainnet, walletClient, publicClient);
+
+    contractTestingUtils.mockCall('nonces', [10n]);
+    contractTestingUtils.mockCall('name', ['Ethereum Staking Mock']);
+
+    const mockSpender = padHex('0x', { size: 20 });
+    // Mocking the wallet client since couldn't find a way to mock
+    // through eth-testing.
+    const mockSignature = serializeSignature({
+      r: '0x1',
+      s: '0x1',
+      v: 0n,
+      yParity: 1,
+    });
+    const signTypedDataSpy = jest
+      .spyOn(walletClient, 'signTypedData')
+      .mockReturnValue(Promise.resolve(mockSignature));
+
+    await handler
+      .withToken(Token.pufETHwstE)
+      .getPermitSignature(mockAccount, mockSpender, 1n);
+
+    const salt = TOKENS_SALT[Token.pufETHwstE]?.[Chain.Mainnet];
+    expect(salt).toBeDefined();
+    expect(signTypedDataSpy.mock.lastCall?.[0].domain?.salt).toBe(salt);
+  });
 });