eventmap-gen

Overview ¶

Command eventmap-gen generates mapping code between domain events and event sourcing types.

Usage:

go run github.com/getpup/pupsourcing/cmd/eventmap-gen \
  -input internal/core/component/user/domain/user/events \
  -output internal/infrastructure/component/user/persistence/es/generated

The tool discovers domain event structs in the input directory and generates strongly-typed mapping functions for converting between domain events and pupsourcing core types (es.Event and es.PersistedEvent).

Versioned Events ¶

The tool supports event versioning through directory structure. Subdirectories named v1, v2, v3, etc. indicate the event version:

events/
  v1/
    user_registered.go
    user_email_changed.go
  v2/
    user_registered.go  // New version with different schema

If no version directory exists, the default version is 1.

Generated Code ¶

The tool generates:

• EventTypeOf(e any) - Resolves event type string from domain event
• ToESEvents(boundedContext, aggregateType, aggregateID, events, opts...) - Converts domain events to es.Event
• FromESEvents[T](events) - Converts es.PersistedEvent to domain events (using generics)
• Type-safe helpers per event (ToUserRegisteredV1, FromUserRegisteredV1, etc.)

Clean Architecture ¶

This tool maintains clean architecture boundaries:

• Domain events remain pure (no dependency on pupsourcing)
• Generated code lives in the infrastructure layer
• Generated code may depend on pupsourcing
• No runtime reflection or magic
• All mapping is explicit and inspectable