Tokenized Stake + Interest Bearing CFX

Using Conflux Network staking to create interest-bearing wrapped CFX in the ERC-20 token standard.

Testnet deployed address: 0x890cE2348eD62C0DF79eB0d81b0c7C3aCD103670

NOTE: This project is not audited. It is simply a demonstration of an idea for building on Conflux.

Interactions

Basic ERC-20 functionality (balanceOf, transfer, transferFrom, approve, allowance, totalSupply)
receive is the default fallback for depositing CFX to convert into sCFX. To interact, send greater than 1 CFX to contract address.
withdraw is called when converting sCFX to CFX. It withdraws all of a users sCFX.

Developer Notes

THe base of the smart contract is the Open Zeppelin ERC-20 template in order to start from a audited and prove-secure contract.

The main modifications are as follows (+ associated functionality for calculating interest, staking, unstaking):

Intermediary step for the _transfer() function to calculate interest and mint interest for the sender and recipient before calling the origin _transfer() function
Fallback function receive() for receiving deposits to convert CFX into sCFX
withdraw() function that allows a user to convert all their sCFX into CFX

When deploying, 1 CFX is deposited into the contract to make sure withdraws can always be processed (there is always 1 CFX that can be staked).

Uses Conflux Truffle and the Conflux docker image.

Improvements:

Better + more complete test cases
More efficient interest calculation (values are currently hard coded in a way to create a binary search for calculating interest)
Withdraw function for specific amounts instead of all
Mechanism to deposit less than 1 CFX

Local Testing

Start Docker image:

docker pull confluxchain/conflux-rust
docker run -p 12537:12537 --name cfx-node confluxchain/conflux-rust

Run test cases:

cfxtruffle test

Test cases are using the built in Mocha/Chai testing framework Truffle Assertions

Clear docker image:

docker kill cfx-node
docker rm cfx-node

Testnet Deployment

Command to deploy to testnet:

cfxtruffle deploy --network testnet

.env file setup:

PRIVATE_KEY=<insert private key here>

Current testnet deployment:

1_deploy.js
===========
   Replacing 'StakedCFX'
   ---------------------
   > transaction hash:    0x11189da87f7e39b4b340cce3e04583ca5f6e95d810198062571b828bda2b1689
   > Blocks: 4            Seconds: 4
   > contract address:    0x890cE2348eD62C0DF79eB0d81b0c7C3aCD103670
   > block number:        3716174
   > block timestamp:     1606575225
   > account:             0x15fd1E4F13502b1a8BE110F100EC001d0270552d
   > balance:             354.341266202675765994
   > gas used:            2755284 (0x2a0ad4)
   > gas price:           20 GDrip
   > value sent:          1 CFX
   > total cost:          1.05510568 CFX
   > Saving artifacts
   -------------------------------------
   > Total cost:          1.05510568 CFX
Summary
=======
> Total deployments:   1
> Final cost:          1.05510568 CFX