11. Testing Method Security
Prev | Part III. Testing | Next

## 11. Testing Method Security

This section demonstrates how to use Spring Security’s Test support to test method based security. We first introduce a `MessageService` that requires the user to be authenticated in order to access it.

    public class HelloMessageService implements MessageService {

    	@PreAuthorize("authenticated")
    	public String getMessage() {
    		Authentication authentication = SecurityContextHolder.getContext()
    															.getAuthentication();
    		return "Hello " + authentication;
    	}
    }

The result of `getMessage` is a String saying "Hello" to the current Spring Security `Authentication`. An example of the output is displayed below.

    Hello org.springframework.security.authentication.UsernamePasswordAuthenticationToken@ca25360: Principal: org.springframework.security.core.userdetails.User@36ebcb: Username: user; Password: [PROTECTED]; Enabled: true; AccountNonExpired: true; credentialsNonExpired: true; AccountNonLocked: true; Granted Authorities: ROLE_USER; Credentials: [PROTECTED]; Authenticated: true; Details: null; Granted Authorities: ROLE_USER

## 11.1 Security Test Setup

Before we can use Spring Security Test support, we must perform some setup. An example can be seen below:

    @RunWith(SpringJUnit4ClassRunner.class)
    @ContextConfiguration
    public class WithMockUserTests {

This is a basic example of how to setup Spring Security Test. The highlights are:

| `@RunWith` instructs the spring-test module that it should create an `ApplicationContext`. This is no different than using the existing Spring Test support. For additional information, refer to the Spring Reference
| `@ContextConfiguration` instructs the spring-test the configuration to use to create the `ApplicationContext`. Since no configuration is specified, the default configuration locations will be tried. This is no different than using the existing Spring Test support. For additional information, refer to the Spring Reference

| Note
Spring Security hooks into Spring Test support using the `WithSecurityContextTestExecutionListener` which will ensure our tests are ran with the correct user. It does this by populating the `SecurityContextHolder` prior to running our tests. After the test is done, it will clear out the `SecurityContextHolder`. If you only need Spring Security related support, you can replace `@ContextConfiguration` with `@SecurityTestExecutionListeners`.

Remember we added the `@PreAuthorize` annotation to our `HelloMessageService` and so it requires an authenticated user to invoke it. If we ran the following test, we would expect the following test will pass:

    @Test(expected = AuthenticationCredentialsNotFoundException.class)
    public void getMessageUnauthenticated() {
    	messageService.getMessage();
    }

## 11.2 @WithMockUser

The question is "How could we most easily run the test as a specific user?" The answer is to use `@WithMockUser`. The following test will be run as a user with the username "user", the password "password", and the roles "ROLE_USER".

    @Test
    @WithMockUser
    public void getMessageWithMockUser() {
    String message = messageService.getMessage();
    ...
    }

Specifically the following is true:

- The user with the username "user" does not have to exist since we are mocking the user
- The `Authentication` that is populated in the `SecurityContext` is of type `UsernamePasswordAuthenticationToken`
- The principal on the `Authentication` is Spring Security’s `User` object
- The `User` will have the username of "user", the password "password", and a single `GrantedAuthority` named "ROLE_USER" is used.

Our example is nice because we are able to leverage a lot of defaults. What if we wanted to run the test with a different username? The following test would run with the username "customUser". Again, the user does not need to actually exist.

    @Test
    @WithMockUser("customUsername")
    public void getMessageWithMockUserCustomUsername() {
    	String message = messageService.getMessage();
    ...
    }

We can also easily customize the roles. For example, this test will be invoked with the username "admin" and the roles "ROLE_USER" and "ROLE_ADMIN".

    @Test
    @WithMockUser(username="admin",roles={"USER","ADMIN"})
    public void getMessageWithMockUserCustomUser() {
    	String message = messageService.getMessage();
    	...
    }

If we do not want the value to automatically be prefixed with ROLE_ we can leverage the authorities attribute. For example, this test will be invoked with the username "admin" and the authorities "USER" and "ADMIN".

    @Test
    @WithMockUser(username = "admin", authorities = { "ADMIN", "USER" })
    public void getMessageWithMockUserCustomAuthorities() {
    	String message = messageService.getMessage();
    	...
    }

Of course it can be a bit tedious placing the annotation on every test method. Instead, we can place the annotation at the class level and every test will use the specified user. For example, the following would run every test with a user with the username "admin", the password "password", and the roles "ROLE_USER" and "ROLE_ADMIN".

    @RunWith(SpringJUnit4ClassRunner.class)
    @ContextConfiguration
    @WithMockUser(username="admin",roles={"USER","ADMIN"})
    public class WithMockUserTests {

## 11.3 @WithAnonymousUser

Using `@WithAnonymousUser` allows running as an anonymous user. This is especially convenient when you wish to run most of your tests with a specific user, but want to run a few tests as an anonymous user. For example, the following will run withMockUser1 and withMockUser2 using @WithMockUser and anonymous as an anonymous user.

    @RunWith(SpringJUnit4ClassRunner.class)
    @WithMockUser
    public class WithUserClassLevelAuthenticationTests {

    	@Test
    	public void withMockUser1() {
    	}

    	@Test
    	public void withMockUser2() {
    	}

    	@Test
    	@WithAnonymousUser
    	public void anonymous() throws Exception {
    		// override default to run as anonymous user
    	}
    }

## 11.4 @WithUserDetails

While `@WithMockUser` is a very convenient way to get started, it may not work in all instances. For example, it is common for applications to expect that the `Authentication` principal be of a specific type. This is done so that the application can refer to the principal as the custom type and reduce coupling on Spring Security.

The custom principal is often times returned by a custom `UserDetailsService` that returns an object that implements both `UserDetails` and the custom type. For situations like this, it is useful to create the test user using the custom `UserDetailsService`. That is exactly what `@WithUserDetails` does.

Assuming we have a `UserDetailsService` exposed as a bean, the following test will be invoked with an `Authentication` of type `UsernamePasswordAuthenticationToken` and a principal that is returned from the `UserDetailsService` with the username of "user".

    @Test
    @WithUserDetails
    public void getMessageWithUserDetails() {
    	String message = messageService.getMessage();
    	...
    }

We can also customize the username used to lookup the user from our `UserDetailsService`. For example, this test would be executed with a principal that is returned from the `UserDetailsService` with the username of "customUsername".

    @Test
    @WithUserDetails("customUsername")
    public void getMessageWithUserDetailsCustomUsername() {
    	String message = messageService.getMessage();
    	...
    }

We can also provide an explicit bean name to look up the `UserDetailsService`. For example, this test would look up the username of "customUsername" using the `UserDetailsService` with the bean name "myUserDetailsService".

    @Test
    @WithUserDetails(value="customUsername", userDetailsServiceBeanName="myUserDetailsService")
    public void getMessageWithUserDetailsServiceBeanName() {
    	String message = messageService.getMessage();
    	...
    }

Like `@WithMockUser` we can also place our annotation at the class level so that every test uses the same user. However unlike `@WithMockUser`, `@WithUserDetails` requires the user to exist.

## 11.5 @WithSecurityContext

We have seen that `@WithMockUser` is an excellent choice if we are not using a custom `Authentication` principal. Next we discovered that `@WithUserDetails` would allow us to use a custom `UserDetailsService` to create our `Authentication` principal but required the user to exist. We will now see an option that allows the most flexibility.

We can create our own annotation that uses the `@WithSecurityContext` to create any `SecurityContext` we want. For example, we might create an annotation named `@WithMockCustomUser` as shown below:

    @Retention(RetentionPolicy.RUNTIME)
    @WithSecurityContext(factory = WithMockCustomUserSecurityContextFactory.class)
    public @interface WithMockCustomUser {

    	String username() default "rob";

    	String name() default "Rob Winch";
    }

You can see that `@WithMockCustomUser` is annotated with the `@WithSecurityContext` annotation. This is what signals to Spring Security Test support that we intend to create a `SecurityContext` for the test. The `@WithSecurityContext` annotation requires we specify a `SecurityContextFactory` that will create a new `SecurityContext` given our `@WithMockCustomUser` annotation. You can find our `WithMockCustomUserSecurityContextFactory` implementation below:

    public class WithMockCustomUserSecurityContextFactory
    	implements WithSecurityContextFactory<WithMockCustomUser> {
    	@Override
    	public SecurityContext createSecurityContext(WithMockCustomUser customUser) {
    		SecurityContext context = SecurityContextHolder.createEmptyContext();

    		CustomUserDetails principal =
    			new CustomUserDetails(customUser.name(), customUser.username());
    		Authentication auth =
    			new UsernamePasswordAuthenticationToken(principal, "password", principal.getAuthorities());
    		context.setAuthentication(auth);
    		return context;
    	}
    }

We can now annotate a test class or a test method with our new annotation and Spring Security’s `WithSecurityContextTestExecutionListener` will ensure that our `SecurityContext` is populated appropriately.

When creating your own `WithSecurityContextFactory` implementations, it is nice to know that they can be annotated with standard Spring annotations. For example, the `WithUserDetailsSecurityContextFactory` uses the `@Autowired` annotation to acquire the `UserDetailsService`:

    final class WithUserDetailsSecurityContextFactory
    	implements WithSecurityContextFactory<WithUserDetails> {

    	private UserDetailsService userDetailsService;

    	@Autowired
    	public WithUserDetailsSecurityContextFactory(UserDetailsService userDetailsService) {
    		this.userDetailsService = userDetailsService;
    	}

    	public SecurityContext createSecurityContext(WithUserDetails withUser) {
    		String username = withUser.value();
    		Assert.hasLength(username, "value() must be non-empty String");
    		UserDetails principal = userDetailsService.loadUserByUsername(username);
    		Authentication authentication = new UsernamePasswordAuthenticationToken(principal, principal.getPassword(), principal.getAuthorities());
    		SecurityContext context = SecurityContextHolder.createEmptyContext();
    		context.setAuthentication(authentication);
    		return context;
    	}
    }

## 11.6 Test Meta Annotations

If you reuse the same user within your tests often, it is not ideal to have to repeatedly specify the attributes. For example, if there are many tests related to an administrative user with the username "admin" and the roles `ROLE_USER` and `ROLE_ADMIN` you would have to write:

    @WithMockUser(username="admin",roles={"USER","ADMIN"})

Rather than repeating this everywhere, we can use a meta annotation. For example, we could create a meta annotation named `WithMockAdmin`:

    @Retention(RetentionPolicy.RUNTIME)
    @WithMockUser(value="rob",roles="ADMIN")
    public @interface WithMockAdmin { }

Now we can use `@WithMockAdmin` in the same way as the more verbose `@WithMockUser`.

Meta annotations work with any of the testing annotations described above. For example, this means we could create a meta annotation for `@WithUserDetails("admin")` as well.

Prev | Up | Next
Part III. Testing | Home | 12. Spring MVC Test Integration