Go Fiber Backend Development Skill

This skill is designed to assist with developing high-quality, scalable backend applications using Go (Golang), Fiber v2, and GORM. It strictly adheres to the project's coding standards and Clean Architecture principles.

1. Core Principles

Architecture:

• •Models: Define data structures (GORM entities) representing database tables.
• •Handlers: Manage HTTP requests and responses, focusing only on the request/response cycle.
• •Routes: Map incoming URLs to specific handlers.
• •Services (Optional): Encapsulate complex business logic, separating it from handlers for better testability.
• •Utils: House reusable helper functions (e.g., Response formatting, Auth handling).

Clean Code:

• •Naming: strictly use snake_case for file/directory names, PascalCase for exported types/functions, and camelCase for variables.
• •Error Handling: Explicitly check if err != nil after every operation that can fail. Propagate errors meaningfully.
• •Responses: Always return a consistent JSON format: { "status": "...", "message": "...", "data": ... }.

Security:

• •Hash passwords using Bcrypt.
• •Implement JWT for authentication, protecting sensitive routes with middleware.
• •Configure CORS explicitly to allow Authorization headers.
• •Critical: If AllowCredentials is true, AllowOrigins MUST NOT use a wildcard (*). Use specific domains or an environment variable.
• •Validate all user inputs rigorously.

2. Implementation Guide

A. Creating a New Feature (CRUD)

When creating a new feature (e.g., "Manage Orders"):

1. •Model (models/order.go): Define the struct with GORM tags (gorm:"primaryKey", json:"id").
2. •Handler (handlers/order_handler.go): Implement handler functions:
   • •GetOrders: Retrieve list.
   • •GetOrder: Retrieve single item by ID.
   • •CreateOrder: Validate input and create new record.
   • •UpdateOrder: Update existing record.
   • •DeleteOrder: Soft delete or hard delete.
3. •Route (routes/setup.go or routes/order_routes.go): Register routes and group by feature (e.g., /api/orders).
4. •AutoMigrate (database/connect.go): Add the new model to db.AutoMigrate(&Order{}).

B. Standard Response Format

Always use the helper functions in utils/response.go:

// Success
return utils.SendSuccessResponse(c, "Data fetched", data)

// Error
return utils.SendErrorResponse(c, fiber.StatusNotFound, "Not found", nil)

C. Error Handling Pattern

Always handle errors gracefully. Avoid panic unless critical during initialization.

// Example in Handler
if err := db.Create(&user).Error; err != nil {
    return utils.JSONResponse(c, fiber.StatusInternalServerError, "Failed to create user", nil)
}

3. Checklist for Every Modification

• • Conforms to snake_case file naming?
• • Exported structs/funcs use PascalCase?
• • go fmt ./... ran successfully?
• • .env is listed in .gitignore and not tracked by Git?
• • Errors handled and returned with proper status codes?
• • JSON response standard followed?