Migration Guides

Major Monster releases may make contracts stricter when the old behavior could hide broken components. These guides describe the observable change, the required consumer migration and the checks to run before upgrading.

Monster 4 → 5

Strict CustomElement option initialization

Learn why option access is no longer allowed from defaults or customization, and how to choose between initMethodSymbol and assembleMethodSymbol.

How to use a migration guide

  1. Search your subclasses for every removed or tightened pattern.
  2. Move code to the lifecycle phase that owns the state it needs.
  3. Run construction, connection and reconnect tests before changing the dependency range.
  4. Review component-specific release notes for unrelated changes in the same major release.

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