GridUnity Take Home Assessment Solution

🚀 Features Implemented

• Access directories using snapshot, list, restore, prune operations
• Enhance list operation to include additional disk-usage metrics
• Implement a check operation that scans the database for any corrupted file
  content
• Use chunking to de-duplicate storage at a more fine-grained level
• GraphQL APIs to test out via tools like Postman

📦 Architecture

.
├── src/
│   ├── config/                 # Database configuration files
│   ├── entities/               # Database entity definitions
│   ├── graphql/
│   │   └── resolvers/          # GraphQL resolvers
│   ├── helpers/                # CLI & server helpers
│   ├── utils/                  # Utility modules (hashing, chunking, etc.)
│   ├── app.ts                  # Entry point for the Koa + Apollo server
│   └── database.ts             # Database connection setup
├── tests/                      # Comprehensive integration & unit tests
├── database.sqlite             # SQLite database file (generated)
├── package.json                # Project dependencies & scripts
└── tsconfig.json               # TypeScript configuration

⚙️ Technologies

• Node.js / TypeScript
• GraphQL (Apollo)
• TypeORM (SQLite Database)
• Koa Framework
• Jest (Testing Framework)

✅ Prerequisites

• Node.js (20.x or later recommended)
• npm or yarn (preferred)

🛠 Installation

1. Clone Repository

   git clone https://github.com/azurespheredev/GridUnity-Assessment
   cd GridUnity-Assessment

2. Install Dependencies

   yarn install

3. Environment Setup

   Create a .env file (for development):

   NODE_ENV=development
   PORT=4000

4. Register Environment Variable (Windows OS)

   Make sure you have these dependencies installed globally

   npm i -g ts-node typescript

   And add <your absolute folder path>/scripts/windows to PATH in environment variable settings.

▶️ Usage

In the root directory of the project, run the following:

Snapshot a Directory

backuptool snapshot --target-directory=./data

List Snapshots

backuptool list

Example Output:

SNAPSHOT  TIMESTAMP                FILE                SIZE        DISTINCT_SIZE
1         2025-03-31 10:58:31.000  data_001.txt        2750        2750
1         2025-03-31 10:58:31.000  data_002.txt        2727        2727
1         2025-03-31 10:58:31.000  data_003.txt        1855        1855
total                                                  7332

Restore a Snapshot

backuptool restore --snapshot-number=1 --output-directory=./out

Prune a Snapshot

backuptool prune --snapshot=1

Check Data Integrity

backuptool check

🧪 Running Tests

yarn test

🧪 GraphQL Resolver Tests:
   √ List snapshots returns correct snapshot details (564 ms)
   √ Get snapshot by ID returns correct snapshot (29 ms)
   √ Create snapshot from the specific directory (23 ms)
   √ Restore snapshot to new directory (20 ms)
   √ Snapshotting twice without changes should not duplicate chunk content (24 ms)
   √ Pruning snapshot does not affect others (40 ms)

Test Suites: 1 passed, 1 total
Tests:       6 passed, 6 total
Snapshots:   0 total
Time:        5.325 s

Tests cover snapshot creation, chunk-based deduplication, restores, pruning safety, and integrity verification.