Fix serial format of StateEvent

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@extollo/lib",
-  "version": "0.13.0",
+  "version": "0.13.1",
   "description": "The framework library that lifts up your code.",
   "main": "lib/index.js",
   "types": "lib/index.d.ts",

src/support/bus/StateEvent.ts

@@ -1,5 +1,5 @@
 import {Container, Inject, Injectable, Instantiable} from '../../di'
-import {Awaitable, ErrorWithContext, JSONState, uuid4} from '../../util'
+import {Awaitable, ErrorWithContext, hasOwnProperty, JSONState, uuid4} from '../../util'
 import {BaseSerializer} from './serial/BaseSerializer'
 import {Event} from './types'
 
@@ -59,6 +59,21 @@ export abstract class StateEvent<T extends JSONState> implements Event {
     }
 }
 
+/** A serialized `StateEvent` instance. */
+export type SerializedStateEvent<T extends JSONState = JSONState> = {
+    state: T,
+    eventUuid: string,
+}
+
+export function isSerializedStateEvent(what: unknown): what is SerializedStateEvent {
+    return (
+        typeof what === 'object' && what !== null
+        && hasOwnProperty(what, 'state')
+        && hasOwnProperty(what, 'eventUuid')
+        && typeof what.eventUuid === 'string'
+    )
+}
+
 /**
  * Generic serializer implementation for StateEvents.
  * Note that this is NOT registered with @ObjectSerializer() because we need to
@@ -80,7 +95,7 @@ export abstract class StateEvent<T extends JSONState> implements Event {
  * ```
  */
 @Injectable()
-export class StateEventSerializer extends BaseSerializer<StateEvent<JSONState>, JSONState> {
+export class StateEventSerializer extends BaseSerializer<StateEvent<JSONState>, SerializedStateEvent> {
     @Inject()
     protected readonly injector!: Container
 
@@ -98,20 +113,24 @@ export class StateEventSerializer extends BaseSerializer<StateEvent<JSONState>,
         return some instanceof this.eventClass
     }
 
-    protected encodeActual(actual: StateEvent<JSONState>): Awaitable<JSONState> {
-        return actual.getState()
+    protected encodeActual(actual: StateEvent<JSONState>): Awaitable<SerializedStateEvent> {
+        return {
+            state: actual.getState(),
+            eventUuid: actual.eventUuid,
+        }
     }
 
-    protected decodeSerial(serial: JSONState): Awaitable<StateEvent<JSONState>> {
+    protected decodeSerial(serial: SerializedStateEvent): Awaitable<StateEvent<JSONState>> {
         const inst = this.injector.makeNew<StateEvent<JSONState>>(this.eventClass)
-        if ( !inst.validate(serial) ) {
+        if ( !isSerializedStateEvent(serial) || !inst.validate(serial.state) ) {
             throw new ErrorWithContext('Invalid serial state', {
                 serial,
                 eventClass: inst.getName(),
             })
         }
 
-        inst.setState(serial)
+        inst.setState(serial.state)
+        inst.eventUuid = serial.eventUuid
         return inst
     }