Message Serialization

• ID: runtime.message-serialization
• Name: Message serialization
• Maturity: GA
• Summary: Serializes and deserializes message payload text through IMessageSerializer, with default SystemTextJsonMessageSerializer.

What It Does

Runtime serialization converts CLR message objects to payload strings and back. MessageModule registers IMessageSerializer to SystemTextJsonMessageSerializer, which uses System.Text.Json web defaults and wraps JSON conversion failures in MessageSerializationException.

Public Surface

Packages

• LiteBus.Messaging
• LiteBus.Messaging.Abstractions

Requires

• runtime.message-module
• runtime.contract-registry

Invariants

• Null message or payload values are rejected.
• Cancellation token is checked before serialization and deserialization.
• JSON and unsupported-type failures are surfaced as MessageSerializationException.

Non-Goals

• Binary encodings in core runtime package.
• Automatic schema migration support.

Observability

No serializer-specific meter or activity contract exists in runtime core. Call sites log serialization exceptions with contract context.

Test Coverage

Covered Use Cases

LiteBusV6CompositionSmokeTests.AddV6CompositionSmoke_ShouldRegisterCoreServicesAndHostedProcessors

• Use case: runtime composition registers serializer service in core graph
• Test kind: Component
• Description: v6 composition smoke validates required runtime service registrations
• Behavior: MessageModule contributes core messaging services including IMessageSerializer
• Expected outcome: composed host contains messaging runtime services
• Remarks: LiteBus.Runtime.UnitTests

PlainMessageTests.Send_FakeCommand_ShouldGoThroughHandlersCorrectly

• Use case: message lifecycle through runtime contracts with serializable models
• Test kind: Unit
• Description: sends plain command through message pipeline
• Behavior: pipeline executes with runtime message contracts and serializer abstraction in place
• Expected outcome: handler pipeline completes with expected result
• Remarks: LiteBus.Mediator.UnitTests

SystemTextJsonMessageSerializerTests

• Use case: Direct serializer behavior covers round trips, custom options, malformed input, unsupported runtime types, JSON null, cancellation, and null arguments.
• Test kind: Unit
• Description: Invokes SystemTextJsonMessageSerializer without an envelope or mediator wrapper.
• Behavior: JSON failures are mapped to MessageSerializationException with the requested type and operation.
• Expected outcome: Valid messages round-trip; invalid inputs retain exception context.
• Remarks: tests/LiteBus.Runtime.UnitTests/Serialization/.

Out-of-Scope Use Cases

• Alternative serializers such as Protobuf or Avro in core runtime package.