Prompt file imported from srnichols/Falsify (
.github/prompts/new-service.prompt.md). Fill in{{id}}before use. Copyright stays with the author.
Create New Service
Scaffold a service layer class following clean architecture.
Required Pattern
import { Logger } from 'pino';
import { z } from 'zod';
import { NotFoundError, ValidationError } from '../errors';
import { {EntityName}Repository } from '../repositories/{entityName}Repository';
// Validation schemas
const Create{EntityName}Schema = z.object({
name: z.string().min(1).max(255),
// ... fields
});
export class {EntityName}Service {
constructor(
private readonly repo: {EntityName}Repository,
private readonly logger: Logger
) {}
async getById(id: string): Promise<{EntityName}> {
const entity = await this.repo.findById(id);
if (!entity) throw new NotFoundError(`{EntityName} {{id}} not found`);
return entity;
}
async getAll(page = 1, pageSize = 20): Promise<PagedResult<{EntityName}>> {
return this.repo.findAll(page, pageSize);
}
async create(input: unknown): Promise<{EntityName}> {
const data = Create{EntityName}Schema.parse(input); // throws ZodError
this.logger.info({ name: data.name }, 'Creating {entityName}');
return this.repo.insert(data);
}
async update(id: string, input: unknown): Promise<{EntityName}> {
await this.getById(id); // Throws NotFoundError if missing
const data = Update{EntityName}Schema.parse(input);
return this.repo.update(id, data);
}
async delete(id: string): Promise<void> {
await this.getById(id);
await this.repo.delete(id);
}
}Rules
- ALL business logic lives in the service layer — not routes, not repositories
- Validate input with Zod schemas at service boundary
- Throw typed errors:
NotFoundError,ValidationError,ConflictError - Use structured logging (pino) with context objects, not string interpolation
- Services are stateless — inject dependencies via constructor
