Fix for GH-2509: WebMvcLinkBuilder.linkTo() ignores basePath for @RepositoryRestController

[ruthst00]

Fixes 2509

What was implemented

1. BasePathAwareWebMvcLinkBuilderFactory.java (new)

A WebMvcLinkBuilderFactory subclass that overrides linkTo(Object invocationValue). When the target controller is annotated with @BasePathAwareController (which @RepositoryRestController is a meta-annotation of), it intercepts the WebHandler.linkTo() call and provides a custom finisher function that prepends the configured basePath to the mapping path before building the UriComponentsBuilder. It uses reflection to access the package-private WebMvcLinkBuilder(UriComponents, TemplateVariables, List<Affordance>) constructor so the returned type is still a proper WebMvcLinkBuilder.

2. RepositoryRestMvcConfiguration.java (modified)

Registers BasePathAwareWebMvcLinkBuilderFactory as a @Bean named basePathAwareWebMvcLinkBuilderFactory, injecting the RepositoryRestConfiguration. Added @author Steve Rutherford to the class Javadoc.

3. BasePathAwareWebMvcLinkBuilderFactoryUnitTests.java (new)

5 unit tests covering:

• @BasePathAwareController gets base path prepended ✅
• @RepositoryRestController gets base path prepended ✅
• Regular (non-SDR) controllers are not affected ✅
• Empty base path is a no-op ✅
• Base path is not double-prepended ✅

---

• You have read the Spring Data contribution guidelines.
• You use the code formatters provided here and have them applied to your changes. Don’t submit any formatting related changes.
• You submit test cases (unit or integration tests) that back your changes.
• You added yourself as author in the headers of the classes you touched. Amend the date range in the Apache license header if needed. For new types, add the license header (copy from another file and set the current year only).