Json serializer does not create a journal file that can be read (NotSupportedException)

[goblinfactory]

When using JsonSerializerAdapter and default settings, the resulting generated journal file cannot be read.

The test below fails with;

System.NotSupportedException : Specified method is not supported.
   at Memstate.JsonNet.SurrogateConverter.ReadJson(JsonReader reader, Type objectType, Object existingValue, JsonSerializer serializer) in C:\src\git-alan-public\memstate-fork-alan\Memstate.JsonNet\SurrogateConverter.cs:line 43

Steps to reproduce the error, run this test

        [Test]
        public async Task Json_file_created_should_be_able_to_be_deserialized()
        {
            Print("Given a journal file");
            var settings = new MemstateSettings { StreamName = "json-example2" };
            settings.Serializers.Register("a-unique-key", _ => new JsonSerializerAdapter(settings));
            settings.Serializer = "a-unique-key";
            var model1 = await new EngineBuilder(settings).BuildAsync<LedgerDB>();

            await model1.ExecuteAsync(new InitAccount(accountNumber: 1, openingBalance: 100.11M, currency: '£'));
            await model1.ExecuteAsync(new InitAccount(accountNumber: 2, openingBalance: 200.22M, currency: '£'));
            await model1.ExecuteAsync(new Transfer(fromAccount: 1, toAccount: 2, amount: 0.01M, currency: '£'));
            var accounts1 = await model1.ExecuteAsync(new GetAccounts());
            await model1.DisposeAsync();
            Assert.True(File.Exists("json-example2.journal"));

            Print("When I create an new LedgerDB that will read the recently created ledger file");
            var model2 = await new EngineBuilder(settings).BuildAsync<LedgerDB>();

            Print("then the journal entries should have been read in");
            var accounts2 = await model2.ExecuteAsync(new GetAccounts());
            Assert.AreEqual(2, accounts2.Count);

            Print("And the in memory object database should be back to the latest state");
            CollectionAssert.AreEqual(accounts1, accounts2);

        }

You can use any Engine<T> with any commands. The important point is the serializer settings.