Bank Contract

This project comprises of two connected contracts deployed on the sepoila Ethereum testnet:

• Bank Contract – Takes care of user deposits, withdrawals and interest claims in sepolia ETH.
• FeeCollector Contract – The feeCollector contracts receives deposit fees from the Bank contract, a source of interest payment.

Both Contracts simulates a banking system where users can receive interests on their deposits.

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Features

• Ether deposits and withdrawal
• Interest calculation and payout
• DepositFee pool(feeCollector contract)
• Pause/unpause transactions Bank administration
• Access control Implementation with open-zeppelin (role based)
• Reentrancy proof implemented with open-zeppelin reentrancy guard
• Modular architeture with seperation of concerns

Quick Step by Step Guide

install dependencies

$ npm install

Create a dot(.)env file in the root directory of your project to contain the following variables

• PRIVATE_KEY = owner_wallet_private_key
• TEST_PRIVATE_KEY = test_wallet_1_private_key
• TEST_PRIVATE_KEY2 = test_wallet_2_private_key
• INFURA_API_URL = https://sepolia.infura.io/v3/YOUR_INFURA_PROJECT_ID

Run Tests Command

$ npx hardhat test

Run Interaction Scripts examples

Administration Scripts Command Examples

• Owner changes owner to test wallet 1 address

$ npx hardhat run scripts/admincontrol.ts change_owner

• owner Pauses the bank to freeze financial operations

$ npx hardhat run scripts/admincontrol.ts owner_pause_bank

• Owner unpauses the bank to resume financial operations

$ npx hardhat run scripts/admincontrol.ts owner_unpause_bank

• Assign role to test wallet 1 address using Owner wallet

$ npx hardhat run scripts/admincontrol.ts owner_assign_role_to_address

• Owner sets new interest rate for Bank contract

$ npx hardhat run scripts/admincontrol.ts owner_set_new_interest rate 5

• Owner set new dust threshold for Bank contract

$ npx hardhat run scripts/admincontrol.ts owner_set_new_dust_threshold 0.000002

• Owner set new dust threshold for fee collector contract

$ npx hardhat run scripts/admincontrol.ts owner_set_new_dust_threshold_fee_collector 0.000002

Deposit Interaction script Commands Examples

• deposit 1 eth using test wallet 1

$ npx hardhat run scripts/deposit.ts test_wallet1_deposit 1 

• Deposit 3 eth using owner wallet

$ npx hardhat run scripts/deposit.ts owner_wallet_deposit 3

Withdrawal Interaction Script Commands Examples

• test wallet 1 withdraw 0.8 ether

$ npx hardhat run scripts/withdraw.ts test_wallet1_withdraw 0.8

• test wallet 2 withdraw all their balance

$ npx hardhat run scripts/withdraw.ts test_wallet2_withdrawAll

• withdrawal from fee collector contract by the owner

$ npx hardhat run scripts/withdraw.ts owner_wallet_withdraw_from_feeCollector 0.5

• emergency fee withdrawal from fee collector by the owner

$ npx hardhat run scripts/withdraw.ts owner_wallet_withdrawAll_from_feeCollector

Contracts Overview

Bank.sol

• Accepts deposits in ether
• Deducts a defined fee percent and sneds it to the feeCollector contract
• Tracks balances and deposit timestamps of users.
• Distributes interest based on a defined APR.
• Admins can do administrator duties such as:
• Pause and unpause Bank
• Assign role to subordinates
• Revoke roles for subordinates
• Renounce their roles
• The Default Admin(owner) can change ownership to a new address.
• Re-configure bank key parameters if they have such privileges
  

FeeCollector.sol

• Receives and holds ether
• Can Send Interest to the Bank Contract for interest payouts
• Admins have access for sensitive operations

Built With

Solidity
Hardhat
TypeScript
Openzeppelin

Author

Built with 🤍 by Raymond Abiola
Feel free to follow my Github account or fork this repo for learning and testing.