idolevittandClaude Sonnet 4.6
a46d5f8dd4
Adds `paths:` YAML frontmatter so each rule only loads into Claude Code context when the agent is working on relevant files, keeping context lean in a large monorepo. - architecture-page-level-auth: fires on page.tsx and layout.tsx - data-prisma-migrations: fires on packages/prisma/** - testing-playwright: fires on playwright dirs, *.e2e.ts, and api e2e dirs - api-thin-controllers: fires on *.controller.ts files only Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>
76 lines
2.4 KiB
Markdown
76 lines
2.4 KiB
Markdown
---
|
|
paths:
|
|
- "apps/api/**/*.controller.ts"
|
|
title: Keep Controllers Thin - HTTP Concerns Only
|
|
impact: HIGH
|
|
impactDescription: Enables technology-agnostic business logic
|
|
tags: api, controllers, http, separation-of-concerns
|
|
---
|
|
|
|
## Keep Controllers Thin - HTTP Concerns Only
|
|
|
|
**Impact: HIGH**
|
|
|
|
Controllers are thin layers that handle only HTTP concerns. They take requests, process them, and map data to DTOs that are passed to core application logic. No application or core logic should be seen in API routes or tRPC handlers.
|
|
|
|
**Controller responsibilities (and ONLY these):**
|
|
- Receive and validate incoming requests
|
|
- Extract data from request parameters, body, headers
|
|
- Transform request data into DTOs
|
|
- Call appropriate application services with those DTOs
|
|
- Transform application service responses into response DTOs
|
|
- Return HTTP responses with proper status codes
|
|
|
|
**Controllers should NOT:**
|
|
- Contain business logic or domain rules
|
|
- Directly access databases or external services
|
|
- Perform complex data transformations or calculations
|
|
- Make decisions about what the application should do
|
|
- Know about implementation details of the domain
|
|
|
|
**Incorrect (business logic in controller):**
|
|
|
|
```typescript
|
|
export async function POST(request: Request) {
|
|
const body = await request.json();
|
|
|
|
// Business logic in controller - BAD
|
|
const user = await prisma.user.findFirst({ where: { id: body.userId } });
|
|
if (!user.canBook) {
|
|
return Response.json({ error: "Cannot book" }, { status: 403 });
|
|
}
|
|
|
|
const booking = await prisma.booking.create({
|
|
data: {
|
|
title: body.title,
|
|
startTime: new Date(body.startTime),
|
|
// Complex logic here...
|
|
}
|
|
});
|
|
|
|
return Response.json(booking);
|
|
}
|
|
```
|
|
|
|
**Correct (thin controller):**
|
|
|
|
```typescript
|
|
export async function POST(request: Request) {
|
|
const body = await request.json();
|
|
|
|
// Validate input
|
|
const input = CreateBookingSchema.parse(body);
|
|
|
|
// Delegate to service
|
|
const result = await bookingService.createBooking(input);
|
|
|
|
// Transform and return
|
|
return Response.json(BookingResponseSchema.parse(result));
|
|
}
|
|
```
|
|
|
|
**The principle:**
|
|
We must detach HTTP technology from our application. The way we transfer data between client and server (whether REST, tRPC, etc.) should not influence how our core application works. HTTP is a delivery mechanism, not an architectural driver.
|
|
|
|
Reference: [Cal.diy Engineering Blog](https://cal.com/blog/engineering-in-2026-and-beyond)
|