编写用于Spring Validator实现的JUnit测试 [英] Writing JUnit tests for Spring Validator implementation
问题描述
我正在使用 Spring Validator 验证我的对象的实现，我想知道如何为像这样的验证器编写单元测试:
I'm using Spring Validator implementations to validate my object and I would like to know how do you write a unit test for a validator like this one:
public class CustomerValidator implements Validator {
private final Validator addressValidator;
public CustomerValidator(Validator addressValidator) {
if (addressValidator == null) {
throw new IllegalArgumentException(
"The supplied [Validator] is required and must not be null.");
}
if (!addressValidator.supports(Address.class)) {
throw new IllegalArgumentException(
"The supplied [Validator] must support the validation of [Address] instances.");
}
this.addressValidator = addressValidator;
}
/**
* This Validator validates Customer instances, and any subclasses of Customer too
*/
public boolean supports(Class clazz) {
return Customer.class.isAssignableFrom(clazz);
}
public void validate(Object target, Errors errors) {
ValidationUtils.rejectIfEmptyOrWhitespace(errors, "firstName", "field.required");
ValidationUtils.rejectIfEmptyOrWhitespace(errors, "surname", "field.required");
Customer customer = (Customer) target;
try {
errors.pushNestedPath("address");
ValidationUtils.invokeValidator(this.addressValidator, customer.getAddress(), errors);
} finally {
errors.popNestedPath();
}
}
}
如何在不调用AddressValidator的实际实现(通过模拟)的情况下对CustomerValidator进行单元测试?我还没有看过像这样的例子...
How can I unit test CustomerValidator without calling the real implementation of the AddressValidator (by mocking it)? I've haven't seen any example like that...
换句话说，我在这里真正想要做的是模拟在CustomerValidator内部调用并实例化的AddressValidator ...有没有办法模拟这个AddressValidator?
In other words, what I really want to do here is to mock the AddressValidator which is called and instanciated inside the CustomerValidator... is there a way to mock this AddressValidator?
还是我看错了方向?也许我需要做的是模拟对ValidationUtils.invokeValidator(...)的调用，但是话又说回来，我不确定该怎么做.
Or maybe I'm looking at it the wrong way? Maybe what I need to do is to mock the call to ValidationUtils.invokeValidator(...), but then again, I'm not sure how to do such a thing.
我想要做的目的非常简单. AddressValidator已经在另一个测试类中进行了全面测试(我们称其为AddressValidatorTestCase).因此，当我为CustomerValidator编写JUnit类时，我不想再次对其进行重新测试" ...因此，我希望AddressValidator始终返回无错误(通过ValidationUtils.invokeValidator(. ..)致电).
The purpose of what I want to do is really simple. The AddressValidator is already fully tested in another test class (let's call it th AddressValidatorTestCase). So when I'm writing my JUnit class for the CustomerValidator, I don't want to "re-test" it all over again... so I want the AddressValidator to always return with no errors (through the ValidationUtils.invokeValidator(...) call).
感谢您的帮助.
编辑(2012/03/18)-我已经设法找到了一个很好的解决方案(我认为...)，它使用JUnit和Mockito作为模拟框架.
EDIT (2012/03/18) - I've managed to find a good solution (I think...) using JUnit and Mockito as the mocking framework.
首先，AddressValidator测试类:
First, the AddressValidator test class:
public class Address {
private String city;
// ...
}
public class AddressValidator implements org.springframework.validation.Validator {
public boolean supports(Class<?> clazz) {
return Address.class.equals(clazz);
}
public void validate(Object obj, Errors errors) {
Address a = (Address) obj;
if (a == null) {
// A null object is equivalent to not specifying any of the mandatory fields
errors.rejectValue("city", "msg.address.city.mandatory");
} else {
String city = a.getCity();
if (StringUtils.isBlank(city)) {
errors.rejectValue("city", "msg.address.city.mandatory");
} else if (city.length() > 80) {
errors.rejectValue("city", "msg.address.city.exceeds.max.length");
}
}
}
}
public class AddressValidatorTest {
private Validator addressValidator;
@Before public void setUp() {
validator = new AddressValidator();
}
@Test public void supports() {
assertTrue(validator.supports(Address.class));
assertFalse(validator.supports(Object.class));
}
@Test public void addressIsValid() {
Address address = new Address();
address.setCity("Whatever");
BindException errors = new BindException(address, "address");
ValidationUtils.invokeValidator(validator, address, errors);
assertFalse(errors.hasErrors());
}
@Test public void cityIsNull() {
Address address = new Address();
address.setCity(null); // Already null, but only to be explicit here...
BindException errors = new BindException(address, "address");
ValidationUtils.invokeValidator(validator, address, errors);
assertTrue(errors.hasErrors());
assertEquals(1, errors.getFieldErrorCount("city"));
assertEquals("msg.address.city.mandatory", errors.getFieldError("city").getCode());
}
// ...
}
AddressValidator已使用此类进行了全面测试.这就是为什么我不想在CustomerValidator中再次重新测试"它的原因.现在，CustomerValidator测试类:
The AddressValidator is fully tested with this class. This is why I don't want to "re-test" it all over again in the CustomerValidator. Now, the CustomerValidator test class:
public class Customer {
private String firstName;
private Address address;
// ...
}
public class CustomerValidator implements org.springframework.validation.Validator {
// See the first post above
}
@RunWith(MockitoJUnitRunner.class)
public class CustomerValidatorTest {
@Mock private Validator addressValidator;
private Validator customerValidator; // Validator under test
@Before public void setUp() {
when(addressValidator.supports(Address.class)).thenReturn(true);
customerValidator = new CustomerValidator(addressValidator);
verify(addressValidator).supports(Address.class);
// DISCLAIMER - Here, I'm resetting my mock only because I want my tests to be completely independents from the
// setUp method
reset(addressValidator);
}
@Test(expected = IllegalArgumentException.class)
public void constructorAddressValidatorNotSupplied() {
customerValidator = new CustomerValidator(null);
fail();
}
// ...
@Test public void customerIsValid() {
Customer customer = new Customer();
customer.setFirstName("John");
customer.setAddress(new Address()); // Don't need to set any fields since it won't be tested
BindException errors = new BindException(customer, "customer");
when(addressValidator.supports(Address.class)).thenReturn(true);
// No need to mock the addressValidator.validate method since according to the Mockito documentation, void
// methods on mocks do nothing by default!
// doNothing().when(addressValidator).validate(customer.getAddress(), errors);
ValidationUtils.invokeValidator(customerValidator, customer, errors);
verify(addressValidator).supports(Address.class);
// verify(addressValidator).validate(customer.getAddress(), errors);
assertFalse(errors.hasErrors());
}
// ...
}
就是这样.我发现此解决方案非常干净...但是让我知道您的想法.好吗?太复杂了吗? 感谢您的反馈.
That's about it. I found this solution pretty clean... but let me know what you think. Is it good? Is it too complicated? Thanks for your feedback.
推荐答案
这是一个非常简单的测试，没有任何模拟. (只是错误对象的创建有点棘手)
It is a really straight forward test without any mock. (just the error-object creation is a bit tricky)
@Test
public void testValidationWithValidAddress() {
AdressValidator addressValidator = new AddressValidator();
CustomValidator validatorUnderTest = new CustomValidator(adressValidator);
Address validAddress = new Address();
validAddress.set... everything to make it valid
Errors errors = new BeanPropertyBindingResult(validAddress, "validAddress");
validatorUnderTest.validate(validAddress, errors);
assertFalse(errors.hasErrors());
}
@Test
public void testValidationWithEmptyFirstNameAddress() {
AdressValidator addressValidator = new AddressValidator();
CustomValidator validatorUnderTest = new CustomValidator(adressValidator);
Address validAddress = new Address();
invalidAddress.setFirstName("")
invalidAddress.set... everything to make it valid exept the first name
Errors errors = new BeanPropertyBindingResult(invalidAddress, "invalidAddress");
validatorUnderTest.validate(invalidAddress, errors);
assertTrue(errors.hasErrors());
assertNotNull(errors.getFieldError("firstName"));
}
顺便说一句:如果您真的想使其复杂化并通过模拟使其复杂化，请查看
BTW: if you really want to make it more complicate and make it complicate by a mock, then have a look at this Blog, they use a two mocks, one for the object to test (ok, this is useful if you can not create one), and a second for the Error object (I think this is more complicated the it must be.)
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