springboot-migration

# Spring Boot Migration ## Purpose Use this skill for phased upgrade work on existing Spring Boot applications. This skill adds value through the migration scanner, the Boot 4 / Modulith 2 / Testcontainers 2 reference guides, and a strict migration order that avoids mixing too many changes at once. ## Critical rules - Never migrate blindly. Scan the codebase first. - Never apply every migration at once. Follow phased upgrades. - Treat Spring Boot 4, Spring Modulith 2, and Testcontainers 2 as the intended target stack for this skill unless the user asks for a narrower target. Boot 4's Java baseline is 17; recommend Java 25 for new compile targets but do not force an upgrade past what the migration actually requires. - Verify after each phase and stop when failures appear. ## Workflow ### Step 1: Scan the project Use the migration scanner before planning or editing. It reads `pom.xml`, `build.gradle`, or `build.gradle.kts` (whichever the project has) plus Java sources, properties files, and Flyway migrations: ```bash python3 "${CLAUDE_SKILL_DIR}/scripts/scan_migration_issues.py" /path/to/project ``` Use the scan output to identify: - current Spring Boot version - starter rename work - annotation and import migrations - configuration changes - Spring Modulith compatibility - Testcontainers compatibility ### Step 2: Identify which migrations apply Load only the references that match the codebase: | Migration | Trigger | Read | |-----------|---------|------| | Spring ...