fix & improve serde integration test

could use some more coverage tho...

src/CWSimulateApp.spec.ts

@@ -1,6 +1,8 @@
 import { toBase64 } from '@cosmjs/encoding';
 import fs from 'fs';
 import { CWSimulateApp } from './CWSimulateApp';
+import * as persist from './persist';
+import { TestContract } from '../testing/wasm-util';
 
 const bytecode = fs.readFileSync('./testing/cw_simulate_tests-aarch64.wasm');
 
@@ -11,7 +13,11 @@ describe('de/serialize', () => {
       ref.wasm.create('alice', bytecode);
       ref.wasm.create('bob',   bytecode);
 
-      const clone = CWSimulateApp.deserialize(ref.serialize());
+      const response = await ref.wasm.instantiateContract('alice', [], 1, {}, '');
+      const address = response.unwrap().events[0].attributes[0].value;
+
+      const bytes = persist.save(ref);
+      const clone = await persist.load(bytes);
       expect(clone.chainId).toStrictEqual(ref.chainId);
       expect(clone.bech32Prefix).toStrictEqual(ref.bech32Prefix);
 
@@ -21,6 +27,9 @@ describe('de/serialize', () => {
       expect(code2.creator).toStrictEqual('bob');
       expect(toBase64(code1.wasmCode)).toStrictEqual(toBase64(ref.wasm.store.getObject('codes', 1, 'wasmCode')));
       expect(toBase64(code2.wasmCode)).toStrictEqual(toBase64(ref.wasm.store.getObject('codes', 2, 'wasmCode')));
+
+      let result = await clone.wasm.executeContract('alice', [], address, { debug: { msg: 'foobar' }});
+      expect(result.ok).toBeTruthy();
     }
   })
 })