@Override
    public List<ValidationEvent> validate(Model model) {
        List<ValidationEvent> events = new ArrayList<>();
        for (ServiceShape serviceShape : model.getServiceShapesWithTrait(EndpointRuleSetTrait.class)) {
            if (serviceShape.hasTrait(EndpointTestsTrait.ID)) {
                EndpointRuleSet ruleSet = serviceShape.expectTrait(EndpointRuleSetTrait.class).getEndpointRuleSet();
                EndpointTestsTrait testsTrait = serviceShape.expectTrait(EndpointTestsTrait.class);

                // Test/Rule evaluation throws RuntimeExceptions when evaluating, wrap these
                // up into ValidationEvents for automatic validation.
                for (EndpointTestCase endpointTestCase : testsTrait.getTestCases()) {
                    try {
                        TestEvaluator.evaluate(ruleSet, endpointTestCase);
                    } catch (RuntimeException e) {
                        events.add(error(serviceShape, endpointTestCase, e.getMessage()));
                    }
                }
            }
        }
        return events;
    }
Validator to ensure that test cases for rule-sets pass type checking evaluation.
smithy-rules-engine/src/main/java/software/amazon/smithy/rulesengine/validators/RuleSetTestCaseValidator.java