[mcollovati]

Fixes #25022

new feature · vaadin-spring · Spring apps with @EnableVaadin on
more than one configuration class

Applications can now put @EnableVaadin with packages on several
configuration classes, for example one per module, and Vaadin scans the
packages of all of them. Before, a Spring Boot application failed at
startup with BeanDefinitionOverrideException, and plain Spring kept
only the packages of the last annotation.

Risks:

• ⚠️ Behaviour change: plain Spring applications with several
  @EnableVaadin annotations now scan all their packages, not only the
  packages of the last annotation processed

• ✅ No public API, security, memory, serialization, threading,
  performance or migration impact

• Changed VaadinScanPackagesRegistrar to add the packages of each
  @EnableVaadin to the bean definition that is already registered,
  instead of registering a second one

  • The packages keep their order and duplicates are removed

• Turned VaadinScanPackages into a package-private record that holds
  an unmodifiable list

• Documented in EnableVaadin that packages from several annotations
  are merged

• Added VaadinScanPackagesRegistrarTest, which runs with bean
  definition overriding disabled, as in Spring Boot

• Based on Make VaadinScanPackages serializable and merge scan packages correctly #25062 by @Hariharan02112004

[mcollovati]

Type of change

• Feature

Test coverage

• VaadinScanPackagesRegistrarTest registers two configuration classes
  with @EnableVaadin and shared packages, with bean definition
  overriding disabled. It fails on main with
  BeanDefinitionOverrideException.
• The bean's constructor argument is now a List instead of a
  String[]. The vaadin-spring AOT processor tests pass; a native or
  AOT build of a real application was not tried.

[vaadin-review-bot]

Reviewed the changes — left 1 comment.

	Finding
📝	The new javadoc about merging does not say that an annotation without packages contributes nothing and that the default application package is then dropped.

[vaadin-review-bot]

📝 The new javadoc about merging does not say that an annotation without packages contributes nothing and that the default application package is then dropped.

The two paragraphs now read together as "no packages → default application package" plus "packages of all annotations are scanned". But the merge only covers annotations that declare packages, and getDefaultPackages falls back to the auto-configuration packages only when the merged list is empty.

So a @SpringBootApplication carrying a bare @EnableVaadin next to a module's @EnableVaadin("com.acme.a.views") scans only the module package, and routes in the application package silently stop being found. Worth spelling out, since "one annotation per module" is the pattern this PR promotes.

_{EnableVaadin.java:76 · documentation}

[mcollovati]

Documented in EnableVaadin (efb883d): an annotation without packages adds no packages, and the default application package must be listed explicitly when another annotation declares packages. This was already the behaviour before this PR.

[github-actions]

Test Results

 1 665 files  +1   1 750 suites  +1   2h 3m 40s ⏱️ - 4m 14s
12 901 tests +1  12 829 ✅ +1  72 💤 ±0  0 ❌ ±0 
13 534 runs  +1  13 462 ✅ +1  72 💤 ±0  0 ❌ ±0 

Results for commit efb883d. ± Comparison against base commit b234893.

♻️ This comment has been updated with latest results.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
88.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[github-actions]

Pull request created: #6479

Generated by Documentation Bot · agent · 87.5 AIC · ⊞ 11.7K

[github-actions]

Documentation Bot: Draft documentation pull request for this change: vaadin/docs#6479

Files updated:

• articles/flow/integrations/spring/routing.adoc

It was written from the state of this pull request as you see it now. Please review it and mark it ready for review.

Generated by Documentation Bot for #26482 · agent · 87.5 AIC · ⊞ 11.7K · ◷