For Flyway 9.9+ JavaMigration beans are not applied

[gaksenov-cen57237]

When used with Flyway 9.9+,

Actual: Beans of type org.flywaydb.core.api.migration.JavaMigration are not applied during migration phase.

Expected: Flyway is properly configured, so that beans of type org.flywaydb.core.api.migration.JavaMigration are applied during migration phase.

Investigation: io.zonky.test.db.flyway.FlywayWrapper#getConfig picks up a modernConfig in Flyway's config, which doesn't contain an array of JavaMigration objects, therefore missing them. These objects are still present in config property and accessible, though. I don't think JavaMigration was ever deprecated, so the missing javaMigrations property in modernConfig seems like an issue of Flyway itself. However, this particular bug may be fixed using existing Flyway's API.

[gaksenov-cen57237]

As workaround, Flyway's integration can be disabled by creating a no-op bean of type FlywayDatabaseExtension with name "flywayDatabaseExtension"

class NoOpFlywayDatabaseExtension() : FlywayDatabaseExtension() {
    public override fun postProcessBeforeInitialization(bean: Any, beanName: String): Any {
        return bean
    }

    public override fun postProcessAfterInitialization(bean: Any, beanName: String): Any {
        return bean
    }

    fun processPendingOperations() {
        // do nothing
    }
}

Then the Flyway migrations are applied ok, which raises a question - what is the purpose of Flyway's integration in embedded-database-spring-test?

[tomix26]

Thanks for the report. I'll try to investigate it more, but If it works with the flyway database extension disabled, then it's definitely a bug in the library.

The primary purpose of the flyway extension lies in performance optimizations. It offers a more effective background bootstrapping mode, reusing template databases among multiple Spring contexts, and, probably the most important optimization, is the handling of the @FlywayTest annotation. Without FlywayDatabaseExtension and OptimizedFlywayTestExecutionListener, this annotation would trigger a complete cleanup of the database before applying new migrations. The flyway extension can take advantage of template databases to speed it up.

[tomix26]

Ok, just to clarify, how do you register Java migrations with Flyway? Do you do it manually using ClassicConfiguration or FluentConfiguration, and not using the locations property, am I right?

[gaksenov-cen57237]

Thank You @tomix26, looks fixed