💧 WATEERDROP – Full Development & Debugging Documentation

📌 Overview

WATEERDROP is a smart water delivery application with:

• Frontend: React (Vite or CRA) → http://localhost:3000
• Backend: Node.js + Express → http://localhost:8080
• Database: MongoDB Atlas

Features

• Browse products (2L, 5L, 10L, 20L, 30L bottles)
• Add to cart & checkout
• View orders
• Admins can manage products, orders, and view dashboard stats

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🗂 Project Structure

WATEERDROP/
├── backend/
│   ├── server.js
│   ├── routes/
│   ├── models/
│   └── controllers/
├── frontend/
│   ├── src/
│   │   ├── pages/
│   │   ├── components/
│   │   └── App.js
│   └── package.json
└── README.md

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🛠 Development Flow

Phase 1 – Initial Setup

• Created React frontend and Express backend.
• Connected backend to MongoDB Atlas.
• Set up routes for products, orders, and users.

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Phase 2 – Routing & Missing Component Fix

Issue:

Module not found: Error: Can't resolve './pages/AdminDashboard'

Fix:
Created src/pages/AdminDashboard.jsx with quick links to admin sections.

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Phase 3 – Admin Dashboard Enhancement

• Added /admin/stats backend route returning:
  • Total orders
  • Pending orders
  • Delivered orders
  • Total products
  • Low stock count
  • Total users
• Updated AdminDashboard.jsx to fetch and display stats.

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Phase 4 – ESLint Warnings

Warning:

React Hook useEffect has a missing dependency: 'fetchOrders'

Fix:
Wrapped fetchOrders in useCallback and added it to dependency array.

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Phase 5 – Products Page Data Mismatch

API Response:

{
  "total": 5,
  "page": 1,
  "totalPages": 1,
  "products": [
    { "name": "Water Bottle", "sizeLiters": 2, "price": 20, "stock": 100 }
  ]
}

Fix: Updated frontend to use p.sizeLiters instead of missing fields.

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Phase 6 – CORS Issue

Error:

Access to XMLHttpRequest at 'http://localhost:8080/products' from origin 'http://localhost:3000' has been blocked by CORS policy

Cause: Backend not sending Access-Control-Allow-Origin header.

Fix:

import cors from 'cors';
app.use(cors({
  origin: 'http://localhost:3000',
  credentials: true
}));

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Phase 7 – Running Both Frontend & Backend Together

Options:

1. Development: Use "proxy": "http://localhost:8080" in frontend package.json.
2. Production: Serve React build from Express backend.

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Phase 8 – Parallax Landing Page

• Created ParallaxSection component.
• Built Home.jsx with parallax sections, feature bands, and CTAs.

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🔄 Flowchart – Request Lifecycle

flowchart TD
    A[User in Browser] -->|Clicks Products| B[React Frontend]
    B -->|Axios GET /products| C[Express Backend]
    C -->|Query| D[MongoDB Atlas]
    D -->|Data| C
    C -->|JSON Response + CORS Headers| B
    B -->|Render Products| A

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🐞 Troubleshooting Guide

Symptom	Likely Cause	Fix
Module not found	Missing file/component	Create file or fix import path
React Hook missing dependency	Function used in useEffect not in deps	Wrap in useCallback or inline
Failed to load products	Field mismatch or undefined array	Match API keys, add safe checks
CORS error	Backend not allowing frontend origin	Enable CORS in backend
All pages failing	API calls blocked by browser	Fix CORS or use proxy

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📊 System Architecture

graph LR
    subgraph Frontend [React App – Port 3000]
        UI[UI Components]
        State[State Management]
    end

    subgraph Backend [Express API – Port 8080]
        Routes[API Routes]
        Controllers[Controllers]
        Models[MongoDB Models]
    end

    subgraph Database [MongoDB Atlas]
        Collections[Products, Orders, Users]
    end

    UI --> State
    State --> Routes
    Routes --> Controllers
    Controllers --> Models
    Models --> Collections

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✅ Current Status

• Backend: Running on 8080, CORS fixed, API functional.
• Frontend: Running on 3000, pages render correctly.
• Admin Dashboard: Stats working.
• Products Page: Displays items from backend.
• Parallax Home Page: Built and styled.

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🚀 Next Steps

1. Deploy backend & frontend together.
2. Secure admin routes with authentication.
3. Add error boundaries for better UX.
4. Apply consistent UI styling.

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📌 Notes

• Start backend before frontend in dev.
• Use .env for sensitive configs.
• Update CORS config for deployed domain.

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