【发布时间】：2012-04-02 10:50:47
【问题描述】：
我正在使用Spring Validator 实现来验证我的对象，我想知道您如何为这样的验证器编写单元测试：
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（通过模拟它）的情况下对 CustomerValidator 进行单元测试？没见过这样的例子……
换句话说，我在这里真正想做的是模拟在 CustomerValidator 内部调用和实例化的 AddressValidator...有没有办法模拟这个 AddressValidator？
或者我看错了？也许我需要做的是模拟对 ValidationUtils.invokeValidator(...) 的调用，但话又说回来，我不知道该怎么做。
我想做的事情的目的很简单。 AddressValidator 已经在另一个测试类中进行了全面测试（我们称之为 AddressValidatorTestCase）。因此，当我为 CustomerValidator 编写 JUnit 类时，我不想重新“重新测试”它......所以我希望 AddressValidator 始终返回没有错误（通过 ValidationUtils.invokeValidator(. ..) 打电话）。
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...），使用 JUnit 和 Mockito 作为模拟框架。
一、AddressValidator测试类：
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 已通过此类进行了全面测试。这就是为什么我不想在 CustomerValidator 中重新“重新测试”它。现在，CustomerValidator 测试类：
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。我发现这个解决方案很干净......但让我知道你的想法。好吗？是不是太复杂了？ 感谢您的反馈。
【问题讨论】：
-
您应该创建一个答案，而不是用答案编辑原始问题。然后你可以接受你的答案（如果你认为它仍然是最好的）。我相信这是处理这种情况的正常方式。如果其他人有同样的问题，有一个公认的答案总是好的。
-
我认为这些行应该指的是customerValidator，而不是addressValidator。我真的看不出验证是否调用了 validator.supports 的意义——这是您感兴趣的 validate 方法调用。我会说。验证（addressValidator）.supports（Address.class）； // verify(addressValidator).validate(customer.getAddress(), errors);
-
这仅测试“快乐”路径。即使所有其他客户详细信息可能正确，您如何测试 AddressValidator 失败是否会导致 CustomerValidator 失败并出现地址错误？
标签： spring junit mocking validation