rmi7 / minimal-market

Ethereum Dapp Minimal Market

Minimal Market

This is my final project ("online marketplace") for the ConsenSys Developer Program 2018.

Other documents:

• Design Pattern Decisions
• Avoiding Common Attacks

Info

Minimal Market is an Ethereum dapp build using truffle, ipfs-api, web3, zeppelin-solidity and VueJS.

The dapp uses IPFS to store all data which is not strictly needed in the smart contracts: text, images, etc.

There is a development server provided by webpack (hot reload) + nodemon.

Dapp in a nutshell

An admin can add store owners, store owners can add stores, to which store owners can add products, these can be bought for ETH by accounts having the shopper role.

User Roles

Inside Minimal Market there are 4 user roles:

• Owner
  • implemented using zeppelin-solidity Ownable.sol
  • initially is set to deploy account
  • is owner of all deployed contracts
  • can enable/disable EmergencyStop
• Admin
  • implemented in Users.sol
  • initially deploy account is set to have admin role
  • can add/remove storeowner
• Owner
  • implemented in Users.sol
  • can add/update/remove his/her stores
  • can add/update/remove products to his/her stores
  • can withdraw any collected funds from products sold (even works if account loses storeowner role)
• Shopper
  • implemented in Users.sol
  • everyone who is not an admin/storeowner
  • can purchase products

All user roles can view all pages: Owner(s), Store(s), Products(s).

Known bugs/limitations

• removed product/store/owner could still be shown in the list of products/stores/owners, solution for now: hard refresh
• removing a storeowner should only be possible if it has no more stores, but that limitation is currently not included, so it'll break the ui
• emergency stop is not implemented in the ui (but it is in the smart contracts + tests)
• updating a store/product is not yet implemented in the ui (but it is in the smart contracts + tests)
• only a few contract events are currently listened for in the ui, so the updating of the ui might not happen as expected, a hard refresh of the page should get you to the correct state.
• does not keep track of transaction that are sent vs mined, this will be needed when using on mainnet/testnet to keep the user happy

creating stores/storeowners/products + purchasing products works!

Requirements

• truffle (tested using v4.1.14)
• ganache-cli (tested using v6.1.3)
• ipfs (golang/js/any is ok as long as it runs on port 5001)
• MetaMask

NOTE: successfully tested inside VirtualBox Ubuntu 16.04 Desktop.

Setup

IPFS

ipfs init

# set CORS headers so that local browser can connect to this IPFS node's API
ipfs config --json API.HTTPHeaders.Access-Control-Allow-Origin '["*"]'
ipfs config --json API.HTTPHeaders.Access-Control-Allow-Methods '["PUT", "GET", "POST"]'

ipfs daemon

ganache-cli

To prevent having to Import Account in MetaMask every time you restart ganache-cli, you could run it with the deterministic flag to always get the same created accounts

ganache-cli -d

demo data

There is a truffle script inside scripts/ which will seed the app with "real" demo data.

• It will retrieve random images and store/product names using faker.
• It will generate random text using lorem-ipsum.
• It will Upload (and pin) all images, store-/productcontent objects to ipfs
• It will create some store owners.
• It will create some stores for each store owner.
• It will create some random products in each store.
• It makes use of the ganache-cli provided accounts (add them to your MetaMask) with the layout as shown below
  • accounts[0] = owner of all contracts + the only admin
  • accounts[1] = first storeowner
  • accounts[2] = second storeowner
  • accounts[3] = third storeowner
  • accounts[4] = fourth storeowner
  • accounts[5] = fifth storeowner
  • accounts[6] = shopper

Install

1. git clone https://github.com/rmi7/minimal-market.git
2. cd minimal-market
3. npm i

Usage

1. make sure ipfs is running
2. make sure ganache-cli is running
3. truffle compile
4. truffle migrate
5. (if you want demo data) truffle exec scripts/seed-demo-data.js
6. npm start to start the development server
7. open localhost:8099 in your browser
8. add the first account from ganache-cli to MetaMask, this is the account used for deploying (user role admin)

Tests

truffle test

There is an overall explanation of the tests inside the Avoiding Common Attacks file: Write Tests

Contract deployement on mainnet/testnet(s)

Not yet implemented

App deployment on IPFS

Not yet implemented

Other

LibraryDemo.sol

I did not see any reason to use an EthPM library in this project (EthPM looks deserted). I therefore added a LibraryDemo.sol contract + tests + migration.

There are 2 EthPM modules which are tested in this contract, oraclize-api and bytes.

• oraclize-api

This is a Contract which you can inherit from. This contract is normally used to send requests to the Oraclize Oracle service. We however are gonna test the helper function parseInt(string _num), which converts an input number as string to a uint.

• bytes

This is a Library which provides some useful bytes arrays functions. We are gonna test the toAddress(bytes _bytes, uint _start) function, which extracts an Ethereum address from the _bytes variable starting at index _start.

License

MIT