Unit Testing Security and Authorization

Overview

This skill provides patterns for unit testing Spring Security authorization logic using @PreAuthorize, @Secured, @RolesAllowed, and custom permission evaluators. It covers testing role-based access control (RBAC), expression-based authorization, custom permission evaluators, and verifying access denied scenarios without full Spring Security context.

When to Use

Use this skill when:

• Testing @PreAuthorize and @Secured method-level security

• Testing role-based access control (RBAC)

• Testing custom permission evaluators

• Verifying access denied scenarios

• Testing authorization with authenticated principals

• Want fast authorization tests without full Spring Security context

Instructions

Follow these steps to test Spring Security authorization:

1. Set Up Security Testing Dependencies

Add spring-security-test to your test dependencies:

<dependency>

  <groupId>org.springframework.security</groupId>

  <artifactId>spring-security-test</artifactId>

  <scope>test</scope>

</dependency>

2. Enable Method Security in Test Configuration

@Configuration

@EnableMethodSecurity

class TestSecurityConfig { }

3. Test with @WithMockUser

@Test

@WithMockUser(roles = "ADMIN")

void shouldAllowAdminAccess() {

  assertThatCode(() -> service.deleteUser(1L))

    .doesNotThrowAnyException();

}

@Test

@WithMockUser(roles = "USER")

void shouldDenyUserAccess() {

  assertThatThrownBy(() -> service.deleteUser(1L))

    .isInstanceOf(AccessDeniedException.class);

}

4. Test Custom Permission Evaluators

@Test

void shouldGrantPermissionToOwner() {

  Authentication auth = new UsernamePasswordAuthenticationToken(

    "alice", null, List.of(new SimpleGrantedAuthority("ROLE_USER"))

  );

  Document doc = new Document(1L, "Test", new User("alice"));

  boolean result = evaluator.hasPermission(auth, doc, "WRITE");

  assertThat(result).isTrue();

}

5. Validate Security is Active

If tests pass unexpectedly, add this assertion to verify security is enforced:

@Test

void shouldRejectUnauthorizedWhenSecurityEnabled() {

  assertThatThrownBy(() -> service.deleteUser(1L))

    .isInstanceOf(AccessDeniedException.class);

}

Quick Reference

Annotation

Description

Example

@PreAuthorize

Pre-invocation authorization

@PreAuthorize("hasRole('ADMIN')")

@PostAuthorize

Post-invocation authorization

@PostAuthorize("returnObject.owner == authentication.name")

@Secured

Simple role-based security

@Secured("ROLE_ADMIN")

@RolesAllowed

JSR-250 standard

@RolesAllowed({"ADMIN", "MANAGER"})

@WithMockUser

Test annotation

@WithMockUser(roles = "ADMIN")

Examples

Basic @PreAuthorize Test

@Service

public class UserService {

  @PreAuthorize("hasRole('ADMIN')")

  public void deleteUser(Long userId) {

    // delete logic

  }

}

// Test

@Test

@WithMockUser(roles = "ADMIN")

void shouldAllowAdminToDeleteUser() {

  assertThatCode(() -> service.deleteUser(1L))

    .doesNotThrowAnyException();

}

@Test

@WithMockUser(roles = "USER")

void shouldDenyUserFromDeletingUser() {

  assertThatThrownBy(() -> service.deleteUser(1L))

    .isInstanceOf(AccessDeniedException.class);

}

Expression-Based Security Test

@PreAuthorize("#userId == authentication.principal.id")

public UserProfile getUserProfile(Long userId) {

  // get profile

}

// For custom principal properties, use @WithUserDetails with a custom UserDetailsService

@Test

@WithUserDetails("alice")

void shouldAllowUserToAccessOwnProfile() {

  assertThatCode(() -> service.getUserProfile(1L))

    .doesNotThrowAnyException();

}

Validation tip: If a security test passes unexpectedly, verify that @EnableMethodSecurity is active on the test configuration — a missing annotation causes all @PreAuthorize checks to be bypassed silently.

See references/basic-testing.md for more basic patterns and references/advanced-authorization.md for complex expressions and custom evaluators.

Best Practices

• **Use @WithMockUser** for setting authenticated user context

• Test both allow and deny cases for each security rule

• Test with different roles to verify role-based decisions

• Test expression-based security comprehensively

• Mock external dependencies (permission evaluators, etc.)

• Test anonymous access separately from authenticated access

• **Use @EnableGlobalMethodSecurity** in configuration for method-level security

Common Pitfalls

• Forgetting to enable method security in test configuration

• Not testing both allow and deny scenarios

• Testing framework code instead of authorization logic

• Not handling null authentication in tests

• Mixing authentication and authorization tests unnecessarily

Constraints and Warnings

• Method security requires proxy: @PreAuthorize works via proxies; direct method calls bypass security

• **@EnableGlobalMethodSecurity**: Must be enabled for @PreAuthorize, @Secured to work

• Role prefix: Spring adds "ROLE_" prefix automatically; use hasRole('ADMIN') not hasRole('ROLE_ADMIN')

• Authentication context: Security context is thread-local; be careful with async tests

• **@WithMockUser limitations**: Creates a simple Authentication; complex auth scenarios need custom setup

• SpEL expressions: Complex SpEL in @PreAuthorize can be difficult to debug; test thoroughly

• Performance impact: Method security adds overhead; consider security at layer boundaries

References

Setup and Configuration

• references/setup.md - Maven/Gradle dependencies and security configuration

Testing Patterns

• references/basic-testing.md - Basic patterns for @PreAuthorize, @Secured, MockMvc testing, and parameterized tests

Advanced Topics

• references/advanced-authorization.md - Expression-based authorization, custom permission evaluators, SpEL expressions

Complete Examples

• references/complete-examples.md - Before/after examples showing transition from manual to declarative security