Tools/domain/projections/ApplicationUpdates.ts

import DomainEvent from "../DomainEvent";
import DomainProjection from "../DomainProjection";
import { ApplicationUpdateFinished } from "../events/ApplicationUpdateFinished";
import { ApplicationUpdateStarted } from "../events/ApplicationUpdateStarted";

export type UpdateDefinition = {
  id: string;
  newVersion: string;
};

export default class ApplicationUpdates implements DomainProjection {
  private pendingUpdates: UpdateDefinition[] = [];
  handle(event: DomainEvent<any>): void {
    if (event.type === "ApplicationUpdateStarted") {
      this.pendingUpdates.push(event.payload);
    } else if (event.type === "ApplicationUpdateFinished") {
      this.pendingUpdates = this.pendingUpdates.filter((pendingUpdate) => {
        return pendingUpdate.id !== event.payload.id;
      });
    }
  }

  getPendingUpdates(): UpdateDefinition[] {
    return this.pendingUpdates;
  }
}