Repository Testing

Using Testcontainers

@SpringBootTest
class ProductRepositoryTest {

    @Container
    static PostgreSQLContainer<?> postgres = new PostgreSQLContainer<>("postgres:15")
        .withDatabaseName("testdb");

    @DynamicPropertySource
    static void configure(DynamicPropertyRegistry registry) {
        registry.add("spring.datasource.url", postgres::getJdbcUrl);
        registry.add("spring.datasource.username", postgres::getUsername);
        registry.add("spring.datasource.password", postgres::getPassword);
    }

    @Autowired
    private ProductRepository repository;

    @Test
    void shouldFindByCategory() {
        repository.save(new Product("Laptop", "electronics"));
        List<Product> result = repository.findByCategory("electronics");
        assertThat(result).hasSize(1);
    }
}

Testing Pyramid

     /  E2E  \
    /----------\
   / Integration \
  /----------------\
 /      Unit        \
/--------------------

Test Types

• Unit: Individual components
• Integration: Component interactions
• E2E: Full user workflows
• Performance: Load/stress testing

Best Practices

• Write tests first (TDD)
• Aim for 80% coverage
• Test edge cases
• Keep tests fast and isolated

Key Points

• Understanding Repository Testing is essential for production systems
• Always consider scalability and maintainability
• Test thoroughly before deploying to production
• Monitor performance and set up alerting

Common Patterns

1. Validation: Always validate input at the boundary
2. Error Handling: Use structured error responses
3. Logging: Log key events for debugging
4. Testing: Unit, integration, and load tests
5. Documentation: Keep docs updated with code changes