Added decorator EventVersion (#64)

* Added decorator EventVersion

* Added new version

* Bug fixed

* 2.3.0

examples/src/heroes/events/impl/hero-killed-dragon.event.ts

@@ -1,5 +1,8 @@
 import { EventStoreAcknowledgeableEvent } from '../../../../../src';
+import { EventVersion } from '../../../../../src/decorators/event-version.decorator';
 
+// This is the second version of this event
+@EventVersion(2)
 export class HeroKilledDragonEvent extends EventStoreAcknowledgeableEvent {
   public declare readonly data: {
     heroId: string;

package.json

@@ -1,6 +1,6 @@
 {
   "name": "nestjs-geteventstore",
-  "version": "2.2.1",
+  "version": "2.3.0",
   "description": "Event Store connector for NestJS-Cqrs",
   "author": "Vincent Vermersch <vincent.vermersch@prestashop.com >",
   "contributors": [

src/decorators/event-version.decorator.ts

@@ -0,0 +1,18 @@
+import { IBaseEvent } from '../interfaces';
+
+export const EventVersion = (version: number) => <
+  T extends { new (...args: any[]): IBaseEvent }
+>(
+  BaseEvent: T,
+) => {
+  const newClass = class extends BaseEvent implements IBaseEvent {
+    constructor(...args: any[]) {
+      super(...args);
+      this.metadata.version = version;
+    }
+  };
+  Object.defineProperty(newClass, 'name', {
+    value: BaseEvent.name,
+  });
+  return newClass;
+};