Token Vendor Machine Challenge

This project is designed to test your skills in smart contract development using Solidity.

Project Overview

You are tasked with implementing a token vendor machine that allows users to buy and sell tokens. The project consists of two main contracts:

1. BlockfulToken.sol: An ERC20 token contract
2. TokenVendor.sol: A vendor contract for buying and selling tokens

Getting Started

To get started with this project, follow these steps:

1. Clone this repository.
2. Run npm install to install Node.js dependencies

Your Tasks

1. Implement the BlockfulToken contract:

   • It should be an ERC20 token with a name, symbol, and 18 decimals.
   • Initial supply should be 1,000,000 tokens.

2. Implement the TokenVendor contract with the following functionality:

   • Allow users to buy tokens with ETH (1 ETH = 100 tokens)
   • Allow users to sell tokens back to the contract
   • Allow the owner to withdraw ETH from the contract
   • Implement proper access control (only owner can withdraw)
   • Emit events for token purchases, sales, and ETH withdrawals

3. Complete the test file test/TokenVendor.t.sol:

   • We've provided some basic "happy path" tests
   • Implement additional tests for edge cases and potential failure scenarios
   • Aim for at least 90% test coverage

4. Update this README with:

   • Any additional setup or testing instructions
   • An explanation of your design decisions
   • Any potential improvements or considerations for a real-world deployment

Bonus Tasks

If you complete the main tasks and want to demonstrate more advanced skills:

1. Implement a simple dynamic pricing mechanism (e.g., price increases as supply decreases)
2. Add a feature to pause/unpause the contract (owner only)
3. Implement a whitelist system for early access to token sales

Usage

Here are some common commands you'll need:

Build

npm run build

Test

npm run  test

Coverage

npm run test:coverage

Evaluation Criteria

Your submission will be evaluated based on:

• Correctness of the implementation
• Code quality and organization
• Test coverage and quality
• Security considerations
• Testnet deployment
• Documentation and comments
• (For bonus tasks) Creativity and effectiveness of additional features

Submission

Please submit your completed project as a Git repository. Make sure to include:

• All source code files
• Complete test suite
• Updated README with your notes and explanations

Note

This project uses Foundry. If you're new to Foundry, check out the Foundry Book for detailed instructions and tutorials.

Good luck with the challenge! We're excited to see your implementation.