new-service

Create New CQRS Service

Create a new service following the CQRS (Command Query Responsibility Segregation) pattern.

Parameters

• name: The service name (e.g., "event", "user", "notification")
• entity: The entity type managed by this service

Instructions

1. Define service interface at src/shared/services/{name}.service.d.ts
2. Implement service at src/main/services/{name}.service.ts
3. Write tests at src/main/services/__tests__/{name}.service.test.ts
4. Follow CQRS pattern strictly:
   • Queries return Observable<T>
   • Commands return ResultAsync<void, ApplicationError>

Interface Template

// src/shared/services/{name}.service.d.ts
import type { Observable } from 'rxjs';
import type { ResultAsync } from 'neverthrow';
import type { ApplicationError } from '@shared/typing';

// Entity type
export interface {Entity} {
  id: string;
  // Add entity fields
  name: string;
  createdAt: Date;
  updatedAt: Date;
}

// Create data type
export interface Create{Entity}Data {
  name: string;
  // Add create fields (no id, createdAt, updatedAt)
}

// Update data type
export interface Update{Entity}Data {
  id: string;
  name?: string;
  // Add optional update fields
}

// Snapshot type for granular updates
export type {Entity}Snapshot = {
  type: 'create' | 'update' | 'delete';
  value: {Entity};
};

// Service interface
export interface {Name}Service {
  // ═══════════════════════════════════════════════════════════════════════
  // QUERIES - Return Observable<T>
  // ═══════════════════════════════════════════════════════════════════════

  /** List all entities */
  list(): Observable<{Entity}[]>;

  /** Get single entity by ID */
  get(id: string): Observable<{Entity} | undefined>;

  /** Stream of granular changes */
  notify(): Observable<{Entity}Snapshot>;

  // ═══════════════════════════════════════════════════════════════════════
  // COMMANDS - Return ResultAsync<void, ApplicationError>
  // ═══════════════════════════════════════════════════════════════════════

  /** Create new entity */
  create(data: Create{Entity}Data): ResultAsync<void, ApplicationError>;

  /** Update existing entity */
  update(data: Update{Entity}Data): ResultAsync<void, ApplicationError>;

  /** Delete entity by ID */
  delete(id: string): ResultAsync<void, ApplicationError>;
}