TopTenBet

Motivation

Smart contract for bet that TokenEconomy mused about in one of their newsletters.

https://tokeneconomy.co/token-economy-30-gazing-into-the-crypstal-ball-3a02cf9fe778

Stefano's personal prediction is that 2018 is the year it all comes crashing down. We are surely building the future and witnessing a revolution, but we’re doing so at the ground floor of the biggest casino ever invented and sometime soon it will close its doors and kick everyone out to go and build in their dusty garages.

So, I think that aside from BTC and ETH, all of the other TOP 10 coins will disappear into oblivion. Staked 10 ETH for charity with Ari on Twitter as he took the over. (BTW, if you can help us write a smart escrow contract for this, we’d be happy to donate a part of the 10 ETH to a charity of your choosing).

Yannick instead thinks we’re still at the very, very early days and the capital influx has just started.

Documentation

This smart contract sets up a bet between Ari and Stefano. The smart contract is set up as a state machine which transitions from setup to end.

State Machine

The state machine is as follows:

setup -> fund -> (implicit wait) -> vote -> payout -> end

VoteOption

Since VoteOption is an enum, the votes are encoded. A vote for Ari is 0, and a vote for Stefano is 1.

Expiry Date

After the expiryDate has passed, either bettor can call expiryRefund() to recover their funds. This is meant to be used if a quorum can't be reached for reasons such as an oracle losing their keys.

Note that after the expiry date, a dishonest bettor that knows they've lost the vote can call expiryRefund() to recover their funds. For this reason, it's important that oracles vote and payout() is called in a timely manner.

Panic Refund

The onlyOwner method panicRefund is implemented to mitigate unforeseen complications. It can be removed if unwanted.

Deployment

Run npm install

Deploy with a tool like Remix

Use truffle-flattener contracts/TopTenBet.sol | pbcopy (macOS) to copy contract code

Example constructor arguments:

"0x1",  // ari
"0x2",  // stefano
"0x3",  // payoutAri
"0x4",  // payoutStefano
"0x5",  // oracle1
"0x6",  // oracle2
"0x7",  // oracle 3
"1546300800",  // endDate (2019-01-01)
"1548979200",  // expiryDate (2019-02-01)
"10000000000000000000"  // 10 ETH in wei

Usage

Use a tool like Remix to interact with the contract.

Bettor

Call fund() with 10 ETH
Wait for endDate
Wait for oracles to vote
Call payout()

If no quorum is reached after expiryDate, call expiryRefund() to retrieve funds.

Oracle

Wait for endDate
Call oracleVote(vote)
- Vote for Ari: 0
- Vote for Stefano: 1

Testing

Automated Testing

truffle test

Manual Testing Reference

Addresses are from the local Ganache instance.

$ truffle compile
$ truffle migrate
$ truffle console
>
TopTenBet.deployed().then(instance => ttb = instance)
ttb.fund({from: "0xf17f52151EbEF6C7334FAD080c5704D77216b732", value: 10*10**18})
ttb.fund({from: "0xC5fdf4076b8F3A5357c5E395ab970B5B54098Fef", value: 10*10**18})

ttb.oracleVote(0, {from: "0x2932b7A2355D6fecc4b5c0B6BD44cC31df247a2e"})
ttb.oracleVote(0, {from: "0x2191eF87E392377ec08E7c08Eb105Ef5448eCED5"})
ttb.oracleVote(0, {from: "0x0F4F2Ac550A1b4e2280d04c21cEa7EBD822934b5"})

ttb.payout()

Future Work

Make oracles dynamic array
Use time freezing library for testing
Timed voting period

dmdque / top-ten-bet