Spring Security provides comprehensive integration with Spring MVC Test and this can also be used when testing controllers using the `@WebMvcTest` slice and `MockMvc`.
For additional details on Spring Security's testing support, refer to Spring Security's {spring-security-docs}#test[reference documentation]).
The above configuration allows Neo4j-related beans in the application to communicate with Neo4j running inside the Testcontainers-managed Docker container.
=== Structure `@Configuration` classes for inclusion in slice tests
Slice tests work by restricting Spring Framework's component scanning to a limited set of components based on their type.
For any beans that are not created via component scanning, for example, beans that are created using the `@Bean` annotation, slice tests will not be able to include/exclude them from the application context.
For a `@WebMvcTest` for an application with the above `@Configuration` class, you might expect to have the `SecurityFilterChain` bean in the application context so that you can test if your controller endpoints are secured properly.
However, `MyConfiguration` is not picked up by @WebMvcTest's component scanning filter because it doesn't match any of the types specified by the filter.
You can include the configuration explicitly by annotating the test class with `@Import(MySecurityConfiguration.class)`.
This will load all the beans in `MyConfiguration` including the `BasicDataSource` bean which isn't required when testing the web tier.
Splitting the configuration class into two will enable importing just the security configuration.
Having a single configuration class can be inefficient when beans of a certain domain needed to be included in slice tests.
Instead, structuring the application's configuration as multiple granular classes with beans for a specific domain can enable importing them only for specific slice tests.
