add EntityCache<T> utility & apply to Project, Vacancy, Program repositories with event-driven invalidation

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: Awakich

projects/social_platform/src/app/api/vacancy/use-cases/delete-vacancy.use-case.ts

@@ -2,17 +2,21 @@
 
 import { inject, Injectable } from "@angular/core";
 import { VacancyRepositoryPort } from "../../../domain/vacancy/ports/vacancy.repository.port";
-import { catchError, map, Observable, of } from "rxjs";
+import { catchError, map, Observable, of, tap } from "rxjs";
 import { fail, ok, Result } from "../../../domain/shared/result.type";
+import { EventBus } from "../../../domain/shared/event-bus";
+import { vacancyDelete } from "../../../domain/vacancy/events/vacancy-deleted.event";
 
 @Injectable({ providedIn: "root" })
 export class DeleteVacancyUseCase {
   private readonly vacancyRepositoryPort = inject(VacancyRepositoryPort);
+  private readonly eventBus = inject(EventBus);
 
   execute(
     vacancyId: number
   ): Observable<Result<void, { kind: "delete_vacancy_error"; cause?: unknown }>> {
     return this.vacancyRepositoryPort.deleteVacancy(vacancyId).pipe(
+      tap(() => this.eventBus.emit(vacancyDelete(vacancyId))),
       map(() => ok<void>(undefined)),
       catchError(error => of(fail({ kind: "delete_vacancy_error" as const, cause: error })))
     );

projects/social_platform/src/app/api/vacancy/use-cases/post-vacancy.use-case.ts

@@ -4,18 +4,22 @@ import { inject, Injectable } from "@angular/core";
 import { VacancyRepositoryPort } from "../../../domain/vacancy/ports/vacancy.repository.port";
 import { CreateVacancyDto } from "../../project/dto/create-vacancy.model";
 import { Vacancy } from "../../../domain/vacancy/vacancy.model";
-import { catchError, map, Observable, of } from "rxjs";
+import { catchError, map, Observable, of, tap } from "rxjs";
 import { fail, ok, Result } from "../../../domain/shared/result.type";
+import { EventBus } from "../../../domain/shared/event-bus";
+import { vacancyCreated } from "../../../domain/vacancy/events/vacancy-created.event";
 
 @Injectable({ providedIn: "root" })
 export class PostVacancyUseCase {
   private readonly vacancyRepositoryPort = inject(VacancyRepositoryPort);
+  private readonly eventBus = inject(EventBus);
 
   execute(
     projectId: number,
     vacancy: CreateVacancyDto
   ): Observable<Result<Vacancy, { kind: "post_vacancy_error"; cause?: unknown }>> {
     return this.vacancyRepositoryPort.postVacancy(projectId, vacancy).pipe(
+      tap(() => this.eventBus.emit(vacancyCreated(projectId, vacancy))),
       map(createdVacancy => ok<Vacancy>(createdVacancy)),
       catchError(error => of(fail({ kind: "post_vacancy_error" as const, cause: error })))
     );

projects/social_platform/src/app/api/vacancy/use-cases/update-vacancy.use-case.ts

@@ -4,18 +4,22 @@ import { inject, Injectable } from "@angular/core";
 import { VacancyRepositoryPort } from "../../../domain/vacancy/ports/vacancy.repository.port";
 import { CreateVacancyDto } from "../../project/dto/create-vacancy.model";
 import { Vacancy } from "../../../domain/vacancy/vacancy.model";
-import { catchError, map, Observable, of } from "rxjs";
+import { catchError, map, Observable, of, tap } from "rxjs";
 import { fail, ok, Result } from "../../../domain/shared/result.type";
+import { EventBus } from "../../../domain/shared/event-bus";
+import { vacancyUpdated } from "../../../domain/vacancy/events/vacancy-updated.event";
 
 @Injectable({ providedIn: "root" })
 export class UpdateVacancyUseCase {
   private readonly vacancyRepositoryPort = inject(VacancyRepositoryPort);
+  private readonly eventBus = inject(EventBus);
 
   execute(
     vacancyId: number,
     vacancy: Partial<Vacancy> | CreateVacancyDto
   ): Observable<Result<Vacancy, { kind: "update_vacancy_error"; cause?: unknown }>> {
     return this.vacancyRepositoryPort.updateVacancy(vacancyId, vacancy).pipe(
+      tap(() => this.eventBus.emit(vacancyUpdated(vacancyId, vacancy))),
       map(updatedVacancy => ok<Vacancy>(updatedVacancy)),
       catchError(error => of(fail({ kind: "update_vacancy_error" as const, cause: error })))
     );

projects/social_platform/src/app/domain/shared/entity-cache.ts

@@ -0,0 +1,25 @@
+/** @format */
+
+import { Observable, shareReplay } from "rxjs";
+
+export class EntityCache<T> {
+  private readonly store = new Map<number, Observable<T>>();
+
+  getOrFetch(id: number, factory: () => Observable<T>): Observable<T> {
+    if (!this.store.has(id)) {
+      const entity$ = factory().pipe(shareReplay(1));
+
+      this.store.set(id, entity$);
+    }
+
+    return this.store.get(id)!;
+  }
+
+  invalidate(id: number): void {
+    this.store.delete(id);
+  }
+
+  clear(): void {
+    this.store.clear();
+  }
+}

projects/social_platform/src/app/domain/vacancy/events/vacancy-created.event.ts

@@ -0,0 +1,23 @@
+/** @format */
+
+import { CreateVacancyDto } from "../../../api/project/dto/create-vacancy.model";
+import { DomainEvent } from "../../shared/domain-event";
+
+export interface VacancyCreated extends DomainEvent {
+  readonly type: "VacancyCreated";
+  readonly payload: {
+    readonly projectId: number;
+    readonly vacancy: CreateVacancyDto;
+  };
+}
+
+export function vacancyCreated(projectId: number, vacancy: CreateVacancyDto): VacancyCreated {
+  return {
+    type: "VacancyCreated",
+    payload: {
+      projectId,
+      vacancy,
+    },
+    occurredAt: new Date(),
+  };
+}

projects/social_platform/src/app/domain/vacancy/events/vacancy-deleted.event.ts

@@ -0,0 +1,20 @@
+/** @format */
+
+import { DomainEvent } from "../../shared/domain-event";
+
+export interface VacancyDelete extends DomainEvent {
+  readonly type: "VacancyDelete";
+  readonly payload: {
+    readonly vacancyId: number;
+  };
+}
+
+export function vacancyDelete(vacancyId: number): VacancyDelete {
+  return {
+    type: "VacancyDelete",
+    payload: {
+      vacancyId,
+    },
+    occurredAt: new Date(),
+  };
+}

projects/social_platform/src/app/domain/vacancy/events/vacancy-updated.event.ts

@@ -0,0 +1,27 @@
+/** @format */
+
+import { CreateVacancyDto } from "../../../api/project/dto/create-vacancy.model";
+import { DomainEvent } from "../../shared/domain-event";
+import { Vacancy } from "../vacancy.model";
+
+export interface VacancyUpdated extends DomainEvent {
+  readonly type: "VacancyUpdated";
+  readonly payload: {
+    readonly vacancyId: number;
+    readonly vacancy: Partial<Vacancy> | CreateVacancyDto;
+  };
+}
+
+export function vacancyUpdated(
+  vacancyId: number,
+  vacancy: Partial<Vacancy> | CreateVacancyDto
+): VacancyUpdated {
+  return {
+    type: "VacancyUpdated",
+    payload: {
+      vacancyId,
+      vacancy,
+    },
+    occurredAt: new Date(),
+  };
+}

projects/social_platform/src/app/infrastructure/repository/industry/industry.repository.ts

@@ -6,10 +6,12 @@ import { map, Observable, tap } from "rxjs";
 import { Industry } from "../../../domain/industry/industry.model";
 import { plainToInstance } from "class-transformer";
 import { IndustryRepositoryPort } from "../../../domain/industry/ports/industry.repository.port";
+import { EntityCache } from "../../../domain/shared/entity-cache";
 
 @Injectable({ providedIn: "root" })
 export class IndustryRepository implements IndustryRepositoryPort {
   private readonly industryAdapter = inject(IndustryHttpAdapter);
+  private readonly entityCache = new EntityCache<Industry>();
 
   readonly industries = signal<Industry[]>([]);
 

projects/social_platform/src/app/infrastructure/repository/program/program.repository.ts

@@ -12,10 +12,12 @@ import { ProjectAdditionalFields } from "../../../domain/project/project-additio
 import { Project } from "../../../domain/project/project.model";
 import { ProgramHttpAdapter } from "../../adapters/program/program-http.adapter";
 import { ProgramRepositoryPort } from "../../../domain/program/ports/program.repository.port";
+import { EntityCache } from "../../../domain/shared/entity-cache";
 
 @Injectable({ providedIn: "root" })
 export class ProgramRepository implements ProgramRepositoryPort {
   private readonly programAdapter = inject(ProgramHttpAdapter);
+  private readonly entityCache = new EntityCache<Program>();
 
   getAll(skip: number, take: number, params?: HttpParams): Observable<ApiPagination<Program>> {
     return this.programAdapter.getAll(skip, take, params);
@@ -26,7 +28,7 @@ export class ProgramRepository implements ProgramRepositoryPort {
   }
 
   getOne(programId: number): Observable<Program> {
-    return this.programAdapter.getOne(programId);
+    return this.entityCache.getOrFetch(programId, () => this.programAdapter.getOne(programId));
   }
 
   create(program: ProgramCreate): Observable<Program> {

projects/social_platform/src/app/infrastructure/repository/project/project.repository.ts

@@ -1,8 +1,7 @@
 /** @format */
 
-import { inject, Injectable, OnDestroy } from "@angular/core";
-import { BehaviorSubject, map, Observable, shareReplay, tap, Subject } from "rxjs";
-import { takeUntil } from "rxjs/operators";
+import { inject, Injectable } from "@angular/core";
+import { BehaviorSubject, map, Observable, tap } from "rxjs";
 import { Project, ProjectCount } from "../../../domain/project/project.model";
 import { ProjectHttpAdapter } from "../../adapters/project/project-http.adapter";
 import { ApiPagination } from "../../../domain/other/api-pagination.model";
@@ -19,10 +18,11 @@ import { RemoveProjectCollaborator } from "../../../domain/project/events/remove
 import { SendVacancyResponse } from "../../../domain/vacancy/events/send-vacancy-response.event";
 import { AcceptVacancyResponse } from "../../../domain/vacancy/events/accept-vacancy-response.event";
 import { RejectVacancyResponse } from "../../../domain/vacancy/events/reject-vacancy-response.event";
+import { EntityCache } from "../../../domain/shared/entity-cache";
 
 @Injectable({ providedIn: "root" })
 export class ProjectRepository implements ProjectRepositoryPort {
-  private readonly cache = new Map<number, Observable<Project>>();
+  private readonly entityCache = new EntityCache<Project>();
   readonly count$ = new BehaviorSubject<ProjectCount>({ my: 0, all: 0, subs: 0 });
 
   private readonly projectAdapter = inject(ProjectHttpAdapter);
@@ -100,14 +100,9 @@ export class ProjectRepository implements ProjectRepositoryPort {
   }
 
   getOne(id: number): Observable<Project> {
-    if (!this.cache.has(id)) {
-      const project$ = this.projectAdapter.fetchOne(id).pipe(
-        map(dto => plainToInstance(Project, dto)),
-        shareReplay(1)
-      );
-      this.cache.set(id, project$);
-    }
-    return this.cache.get(id)!;
+    return this.entityCache.getOrFetch(id, () =>
+      this.projectAdapter.fetchOne(id).pipe(map(dto => plainToInstance(Project, dto)))
+    );
   }
 
   refreshCount(): Observable<ProjectCount> {
@@ -139,6 +134,6 @@ export class ProjectRepository implements ProjectRepositoryPort {
   }
 
   invalidate(id: number): void {
-    this.cache.delete(id);
+    this.entityCache.invalidate(id);
   }
 }