v0.5.0

What's Changed

Added

• Multi-Tenancy Module (eventsource.multitenancy) - First-class multi-tenant support

  • tenant_context ContextVar for managing tenant context across async boundaries
  • tenant_scope async context manager for scoped tenant operations
  • tenant_scope_sync sync context manager for synchronous code paths
  • Helper functions: get_current_tenant(), get_required_tenant(), set_current_tenant(), clear_tenant_context()
  • TenantDomainEvent base class with required tenant_id field and with_tenant_context() class method
  • TenantAwareRepository wrapper that enforces tenant isolation on load/save operations
  • TenantContextNotSetError and TenantMismatchError exceptions for clear error handling
  • Tenant-aware projections with automatic filtering via tenant_filter parameter
  • Public exports from eventsource: tenant_context, tenant_scope, tenant_scope_sync, get_current_tenant, get_required_tenant, set_current_tenant, clear_tenant_context, TenantDomainEvent, TenantContextNotSetError, TenantMismatchError

• Sync Adapter (eventsource.sync) - Synchronous wrappers for async components

  • SyncEventStoreAdapter for using async event stores in synchronous contexts
  • Ideal for Celery tasks, Django management commands, RQ workers, and other sync environments
  • Configurable timeout for operations (default: 30 seconds)
  • Public export from eventsource: SyncEventStoreAdapter

• Testing Module (eventsource.testing) - Comprehensive testing utilities

  • EventBuilder - Fluent builder for creating test events with minimal boilerplate
    • with_aggregate_id(), with_version(), with_tenant_id(), with_timestamp() chainable methods
    • build() for single events, build_sequence() for event chains
  • InMemoryTestHarness - Pre-configured in-memory infrastructure for fast tests
    • Includes event store, event bus, checkpoint repository, and DLQ
    • setup() and teardown() lifecycle methods
    • clear() to reset state between tests
  • EventAssertions - Domain-specific test assertions with clear error messages
    • assert_event_published(), assert_no_events_published(), assert_event_count()
    • assert_event_sequence() for verifying event ordering
    • assert_aggregate_version(), assert_aggregate_state()
  • BDD-style helpers for readable tests:
    • given_events() - Set up initial event history
    • when_command() - Execute a command/action
    • then_event_published() - Assert expected event was published
    • then_no_events_published() - Assert no events were published
    • then_event_sequence() - Assert specific sequence of events
    • then_event_count() - Assert number of events
  • Public exports from eventsource.testing: EventBuilder, InMemoryTestHarness, EventAssertions, given_events, when_command, then_event_published, then_no_events_published, then_event_sequence, then_event_count

• Aggregate create_event() Method - Reduced boilerplate for event creation

  • Auto-populates aggregate_id, aggregate_type, and aggregate_version
  • Auto-populates tenant_id from context when available
  • Explicit kwargs always override auto-populated values
  • Example: self.create_event(OrderShipped, tracking_number="TRACK-001") instead of manually setting all aggregate fields

• Deferred State Pattern - Aggregates without upfront initial state

  • requires_creation_event class attribute on DeclarativeAggregate
  • When True, _get_initial_state() returns None and state is set by first event handler
  • AggregateNotCreatedError raised when accessing state before creation event applied
  • Useful for aggregates where initial state depends entirely on creation event data

• Automatic Type Inference - Less boilerplate for events and aggregates

  • DomainEvent.event_type now auto-infers from class name if not explicitly set
  • DomainEvent.aggregate_type auto-infers from aggregate's aggregate_type when created via create_event()
  • Aggregate state type (TState) auto-detected from Generic parameter

Changed

• InMemoryEventBus - Now thread-safe with proper locking for concurrent access
• AggregateRoot._get_initial_state() - Return type changed from TState to TState | None to support deferred state pattern

Tests

• Added multi-tenancy module tests (tests/unit/multitenancy/)
  • Context management tests (test_context.py)
  • TenantDomainEvent tests (test_events.py)
  • TenantAwareRepository tests (test_repository.py)
  • Projection tenant filtering tests (tests/unit/projections/test_tenant_filter.py)
• Added sync adapter tests (tests/unit/sync/)
  • Adapter functionality tests (test_adapter.py)
  • Concurrency tests (test_concurrency.py)
• Added testing module tests (tests/unit/testing/)
  • EventBuilder tests (test_builder.py)
  • InMemoryTestHarness tests (test_harness.py)
  • EventAssertions tests (test_assertions.py)
  • BDD helpers tests (test_bdd.py)
  • Module structure tests (test_module_structure.py)
• Added aggregate improvement tests
  • create_event() tests (tests/unit/aggregates/test_create_event.py)
  • Deferred state tests (tests/unit/aggregates/test_deferred_state.py)
  • Type inference tests (tests/unit/aggregates/test_aggregate_type_inference.py)
• Added automatic event type inference tests (tests/unit/test_event_type_auto.py)
• Added InMemoryEventBus threading tests (tests/unit/bus/test_memory.py)

Installation

pip install eventsource-py==0.5.0