Add tests.

test/strategy.test.js

@@ -173,6 +173,45 @@ describe('Strategy', function() {
       .authenticate();
   }); // should fail when message is not yet valid
   
+  it('should fail when nonce is invalid', function(done) {
+    clock = sinon.useFakeTimers(1654640839635);
+    
+    chai.passport.use(new Strategy(function(address, cb) {
+      expect(address).to.equal('0xCC6F4DF4B758C4DE3203e8842E2d8CAc564D7758');
+      return cb(null, { id: '248289761001' });
+    }))
+      .request(function(req) {
+        req.connection = {};
+        req.headers.host = 'localhost:3000';
+        req.body = {
+          message: 'localhost:3000 wants you to sign in with your Ethereum account:\n' +
+            '0xCC6F4DF4B758C4DE3203e8842E2d8CAc564D7758\n' +
+            '\n' +
+            'Sign in with Ethereum to the app.\n' +
+            '\n' +
+            'URI: http://localhost:3000\n' +
+            'Version: 1\n' +
+            'Chain ID: 1\n' +
+            'Nonce: VjglqeaSMDbPSYe0K\n' +
+            'Issued At: 2022-06-07T16:28:10.957Z',
+          signature: '0xb303d03782c532e2371e3d75a8b2b093c2dceb5faed5d07d6506be96be783245515db6ad55ad6d598ebdf1f7e1c5cb0d24e7147bbad47d3b9d8dfbcfab2ddcc71b'
+        };
+        req.session = {
+          messages: [],
+          'ethereum:siwe': {
+            nonce: 'Xri9Uq8fydQXUDHx'
+          }
+        };
+      })
+      .fail(function(challenge, status) {
+        expect(challenge).to.deep.equal({ message: 'Invalid nonce.' });
+        expect(status).to.equal(403);
+        done();
+      })
+      .error(done)
+      .authenticate();
+  }); // should fail when message is invalid
+  
   it('should fail when signature is invalid', function(done) {
     chai.passport.use(new Strategy(function(address, cb) {
       expect(address).to.equal('0xCC6F4DF4B758C4DE3203e8842E2d8CAc564D7758');