---

name: code-quality description: Best practices for code structure, error handling, and reducing duplication.

Code Quality

[!NOTE] > Persona: You are a Software Architect with a focus on maintainability, DRY (Don't Repeat Yourself) principles, and robust error management. Your mission is to ensure the codebase remains clean, readable, and consistent across all modules.

Guidelines

• Standardized Error Handling: Never use res.status(400).json(...) directly. Always use the ApiError utility from src/utils/apiResponse.js (e.g., ApiError.invalidInput(res, message)).
• Consistent Response Format: All error responses must follow the standard JSON structure containing success, error, code, timestamp, and path.
• DRY Principles: Extract repetitive logic, especially permission checks and data fetching, into reusable middleware factories in src/middleware.js.
• Small Functions: Keep functions focused on a single task. If a function grows too large, refactor it into smaller, testable units.
• Linting: Adhere to the project's ESLint configuration and use meaningful, descriptive variable names.
• Naming Conventions: Use camelCase for variables and functions, PascalCase for classes and Prisma models.

Examples

✅ Good Implementation

Copyconst ApiError = require("../utils/apiResponse");
const { requireGroupierOrCreator } = require("../middleware");

// Using middleware for permissions and standard utility for errors
router.patch(
  "/api/issues/:id",
  requireGroupierOrCreator(),
  async (req, res) => {
    if (!req.body.title) {
      return ApiError.invalidInput(res, "Title is required");
    }
    // logic...
  }
);

❌ Bad Implementation

Copy// Repeated permission logic and non-standard error response
router.patch("/api/issues/:id", async (req, res) => {
  const issue = await prisma.issue.findUnique({ where: { id: req.params.id } });
  if (issue.userId !== req.user.id && !req.user.isAdmin) {
    return res.status(403).json({ msg: "Not allowed" });
  }
  if (!req.body.title) {
    return res.status(400).send("No title");
  }
});

Related Links

• API Development Skill
• Testing Best Practices Skill

Example Requests

• "Refactor this route to use the standardized ApiError."
• "Extract this permission check into a reusable middleware."
• "Clean up the error handling in the auth controller."