📝 Golang Todo Application

A modern, full-stack todo application built with Go (Fiber) + React + MongoDB

Features • Installation • Documentation • Contributing

🚀 Tech Stack

Backend

🔷 Go
🚅 Fiber (Web Framework)
🍃 MongoDB

Frontend

⚛️ React
⚡ Vite

🏗️ Architecture

graph TD
    subgraph Client["Frontend Client"]
        UI[React UI]
    end

    subgraph Server["Go Fiber Server (main.go)"]
        Main[Main Function]
        ENV[Load Environment]
        DB[MongoDB Connection]
        Router[Fiber Router]
        
        subgraph Endpoints["API Endpoints"]
            GET[GET /api/todos]
            POST[POST /api/todos]
            PATCH[PATCH /api/todos/:id]
            DELETE[DELETE /api/todos/:id]
        end
        
        subgraph Handlers["Handler Functions"]
            getTodos
            createTodo
            updateTodo
            deleteTodo
        end
    end

    subgraph Database["MongoDB Atlas"]
        Collection["Collection: todos</br>Database: golang_db"]
    end

    %% Main Application Flow
    Main --> ENV
    ENV --> DB
    Main --> Router
    Router --> Endpoints

    %% Connect Endpoints to Handlers
    GET --> getTodos
    POST --> createTodo
    PATCH --> updateTodo
    DELETE --> deleteTodo

    %% Connect Handlers to Database
    getTodos --> Collection
    createTodo --> Collection
    updateTodo --> Collection
    deleteTodo --> Collection

    %% Client Interaction
    UI <--> GET
    UI <--> POST
    UI <--> PATCH
    UI <--> DELETE

    %% Styling
    classDef server fill:#f9f,stroke:#333,stroke-width:2px
    classDef database fill:#b5d8ff,stroke:#333,stroke-width:2px
    classDef client fill:#baffc9,stroke:#333,stroke-width:2px
    classDef endpoint fill:#fff5ba,stroke:#333,stroke-width:2px
    
    class Server server
    class Database database
    class Client client
    class GET,POST,PATCH,DELETE endpoint

✨ Features

📱 Responsive Design
🔄 Real-time Updates
🎯 Task Management
✅ Mark Tasks Complete
🗑️ Delete Tasks
💾 Persistent Storage

🛠️ Prerequisites

Before you begin, ensure you have the following installed:

🔷 Go (version 1.16 or later)
💻 Node.js (version 14 or later)
🍃 MongoDB Atlas Account or Local MongoDB
📦 Git

🌟 Installation & Setup

1️⃣ Clone the Repository

git clone https://github.com/vigneshs-dev/golang-to-do-app.git
cd golang-to-do-app

2️⃣ Backend Setup

Install Go Dependencies

go mod download

Environment Variables

Create a .env file in the root directory:

MONGODB_URI=your_mongodb_connection_string
PORT=5000
ENV=development

Replace your_mongodb_connection_string with your MongoDB Atlas connection string or local MongoDB URL.

Run the Backend

go run main.go

The server will start on http://localhost:5000

3️⃣ Frontend Setup

Navigate to the client directory:

cd client

Install dependencies:

npm install

Create a .env file in the client directory:

VITE_API_URL=http://localhost:5000/api

Start the development server:

npm run dev

The frontend will start on http://localhost:5173

📁 Project Structure

project-root/
├── 📜 main.go                 # Main backend server file
├── 📦 go.mod                  # Go modules file
├── 📋 go.sum                  # Go modules checksum
├── 🔒 .env                    # Backend environment variables
├── 📁 client/                 # Frontend React application
│   ├── 📁 src/
│   ├── 📦 package.json
│   ├── 🔒 .env               # Frontend environment variables
│   └── ...
└── 📖 README.md

🔌 API Endpoints

Todo Routes

Method	Endpoint	Description
`GET`	`/api/todos`	Get all todos
`POST`	`/api/todos`	Create a new todo
`PATCH`	`/api/todos/:id`	Update todo status
`DELETE`	`/api/todos/:id`	Delete a todo

💻 Development

Running in Development Mode

Start the backend server:

go run main.go

In a separate terminal, start the frontend development server:

cd client
npm run dev

Building for Production

Build the frontend:

cd client
npm run build

Build the backend:

go build -o app

🚂 Deployment

The application is deployed on Railway.app. For local development, follow the installation steps above.

Environment Variables Required for Deployment

Variable	Description
`MONGODB_URI`	MongoDB connection string
`PORT`	Application port
`ENV`	Set to "production"

❗ Common Issues & Solutions

Backend Issues

🔴 MongoDB Connection Failed
- Check if your MongoDB URI is correct
- Ensure your IP address is whitelisted in MongoDB Atlas
- Verify network connectivity
🔴 Port Already in Use
- Change the port in .env file
- Check if another process is using the same port

Frontend Issues

🔴 API Calls Failed
- Verify the VITE_API_URL in frontend .env file
- Check if the backend server is running
- Verify CORS settings in the backend
🔴 Build Failures
- Clear npm cache: npm cache clean --force
- Delete node_modules and reinstall:
```
rm -rf node_modules
npm install
```