public async Task ApplyRuleChanges_NoExistingRules_CallAddRule()
{
var messagesTypes = new[] { "TestEvent" };
var rules = _ruleBuilder.GenerateSubscriptionRules(messagesTypes, _handlerName).ToArray();
await _ruleBuilder.ApplyRuleChanges(rules, new RuleDescription[] { }, messagesTypes);
await _ruleApplier.Received(1).AddRule(rules.First());
await _ruleApplier.DidNotReceiveWithAnyArgs().RemoveRule(null);
}
