bengotow / dex

Decentralised Exchange (DEX) for Ethereum

Setup

• Fork and clone the repository

• Install NVM

• Switch to Node version specified in .nvmrc

nvm install

• Terminal Tab 1 - Install Truffle
  • Reference: http://truffleframework.com/

npm install -g truffle

• Terminal Tab 2 - Install Test Framework with Ethereum TestRPC

npm install -g ganache-cli

• Terminal Tab 2 - Start Ethereum Blockchain Protocol Node Simulation

ganache-cli \
  --port="8500" \
  --mnemonic "copy obey episode awake damp vacant protect hold wish primary travel shy" \
  --verbose \
  --networkId=3 \
  --gasLimit=7984452 \
  --gasPrice=2000000000;

• Optionally Install Geth and run the Testnet using Geth in the project directory:

  • Show installation directory of Geth and Go, and show Go path Reference

which geth
which go
echo $GOPATH
geth version

• Show where Geth Chain directories are stored:

find ~ -type d -name 'chaindata'

• Install or Upgrade existing version of Geth (if not installed using Homebrew)

brew tap ethereum/ethereum
brew install ethereum
brew upgrade ethereum

• Terminal Tab 1 - Compile and Deploy the FixedSupplyToken Contract

truffle migrate --network development

• Terminal Tab 1 - Run Sample Unit Tests on the Truffle Contract. Truffle Re-Deploys the Contracts

truffle test

Debugging

• Debug the Solidity Smart Contract in Remix IDE
• Verify the Solidity Smart Contract compiles by pasting it in MIST using https://github.com/ltfschoen/geth-node
• Verify the Solidity Smart Contract compiles by deploying it to Ethereum TestRPC using Truffle

TODO

• - Incorporate Automated Market Maker (AMM) similar to that described in 0x Whitepaper

Initial Setup - Truffle, TestRPC, Unit Tests (FixedSupplyContract)

• Install Truffle
  • Reference: http://truffleframework.com/

npm install -g truffle

• Setup Truffle to Manage Contracts (i.e. MetaCoin sample), Migrations and Unit Tests

truffle init

truffle migrate --network development

• Initialise with Front-End

  • Truffle Default
    • https://github.com/trufflesuite/truffle-init-default
  • Truffle Webpack
    • https://github.com/trufflesuite/truffle-init-webpack
    • https://github.com/truffle-box/webpack-box
  • Truffle React
    • http://truffleframework.com/boxes/

• Truffle Configuration File Examples

  • http://truffleframework.com/docs/advanced/configuration
  • Note: Use from to specify the From Address for Truffle Contract Deployment.
  • Use the Mnemonic to Restart TestRPC with the same Accounts.
  • Note: Use provider to specify a Web3 Provider
  • Note: Truffle Build truffle build script for say Webpack is usually in package.json

• Truffle with Test Framework using Ethereum TestRPC (avoid delays in mining transactions with Geth Testnet)

  • Ethereum TestRPC - In-Memory Blockchain Simulation

npm install -g ganache-cli

• Start Ethereum Blockchain Protocol Node Simulation with 10x Accounts on http://localhost:8500
  • Creates 10x Private Keys and provides a Mnemonic. Assigns to each associated Address 100 Ether.
  • Note: Private Keys may be imported into Metamask Client
  • Note: Mnemonic may be used subsequently with Ethereum TestRPC to re-create the Accounts with `

ganache-cli

• Restart TestRPC with Same Accounts (i.e. ganache-cli --mnemonic "copy obey episode awake damp vacant protect hold wish primary travel shy")

ganache-cli --port 8500 --mnemonic <INSERT_MNEMONIC> 

• Add FixedSupplyToken to Truffle Contracts folder

• Remove MetaCoin from Truffle Contracts folder

• Update 2nd Migration file to deploy FixedSupplyToken

• Compile and Deploy the FixedSupplyToken Contract

truffle migrate --network development

• Run Sample Unit Tests on the Truffle MetaCoin Contract. Truffle Re-Deploys the MetaCoin Contracts

truffle test

Troubleshooting

• Try restarting Ganache TestRPC if you encounter error sender doesn't have enough funds to send tx. The upfront cost is: x and the sender's account only has: y

• Fix error Error: Error: Exceeds block gas limit that may occur when sending Gas Limit say of 50000000 when truffle.js has gas property set as gas: 4712388,, by changing to a smaller value: myExchangeInstance.buyToken("FIXED", web3.toWei(4, "finney"), 5, {from: accounts[0], gas: 4000000});

• Fix Error: VM Exception while processing transaction: out of gas. In the buyToken function it always occurs after a certain line of code. Simply increase the Gas Limit to the Mainnet's limit (currently shown as 7984452 at https://ethstats.net/) in both Ganache CLI Flags and in truffle.js