[eth-tokenized]

A collection of smart contracts that enable assets to be represented by an ERC20 token contract that users can then invest in with a stable token.

These contracts make use of the OpenZeppelin library for secure smart contracts, specifically standard functionality for ERC20 tokens and contract management (ownership/state). I would recommend using ZeppelinOS to make the production contracts upgradable.

This project uses the Truffle framework to compile, debug, and deploy contracts. The configuration file truffle.js is configured to deploy contracts to a specified network, and using Infura to deploy to Ropsten and Main networks.

Developer Notes:

VehicleToken and PortfolioToken inherited from ERC223 contract for the tokenFallback() function in the overridden transfer(). However, when transferring to user wallets, this function failed. So the inheritance was removed. Both contracts still fully inherit from ERC20 for standard functionality as well as for minting and burning.
To mitigate the heavy computations done on-chain, some functions from Array256Lib.sol contract were copied over, including _sumElements() and _getMin(). These heavy computations could be done off-chain using the getter methods provided, however it could risk invalid values being submitted.
Main.sol contract is the most bloated and expensive to deploy. This could be mitigated by decoupling the logic for Portfolio investing, especially investPortfolio() as it is the most expensive operation (iterating all VT over all contracts, reading, and computing). Logic was bundled into this contract to avoid extra read expenses.
Most number values fed into contract functions must be sent as BigNumber values. See tests for examples, but generally is done like so: web3.utils.toWei(number.toString(), 'ether')
Assets data can be updated by the contract owner via editAsset() on AssetRegistry, however the token cap is derived from the initial _valueUSD / _valuePerTokenUSD, so there will have to be some balancing if we want to preserve correct calculations. An idea is to pump the value of _valuePerTokenUSD to match the new _valueUSD with the same cap, however this is situational (?)

Setup

Clone the repo and run npm install

You will need Truffle installed globally npm install truffle -g

Finally, install a geth client like Ganache npm install ganache-cli -g

Contracts interface

Read the docs for the 4 smart contracts:

Compile

truffle compile

Run tests

truffle test

That should yield:

Using network 'development'.


Contract: AssetRegistry
  addAsset()
    ✓ adds the asset to storage (126ms)
    ✓ creates an instance of VT token contract
    ✓ calls Main contract addFillableAsset(), increasing its storage count and updating the min value
  editAsset()
    ✓ reverts if the sender is not the contract owner (not to be confused with the asset owner) (46ms)
    ✓ updates storage (105ms)
  fundAsset()
    ✓ reverts if the sender does not own the given asset
    ✓ reverts if the sender does not have enough T tokens to cover the projectedValueUSD (40ms)
    ✓ reverts if the sender has not approved the transfer of T tokens before funding (75ms)
    ✓ sets storage variable funded to true (126ms)

Contract: Main
  constructor()
    ✓ initializes storage variables
  investVehicle()
    ✓ reverts when trying to invest more T tokens than there are VT tokens (75ms)
    ✓ reverts when the sender does not have T tokens (111ms)
    ✓ allows the sender to invest in an asset and receive VT tokens (261ms)
    ✓ calls setAssetFilled() in AssetRegistry when the asset is fully filled
    ✓ does NOT call setAssetFilled() in AssetRegistry when the asset is NOT fully filled (300ms)
    ✓ off the last test, it does update minFillableAmount on Main
  investPortfolio()
    ✓ reverts when there are no assets to invest in
    context: happy path of evenly invested assets
      ✓ mints an equal amount of PT tokens as T tokens invested (242ms)
      ✓ invests those T tokens into the respective VT contracts, evenly
      ✓ updates the lookup of fillable assets count to 0
      ✓ updates the filled state of both assets
      ✓ mints VT tokens for the PT contract (39ms)
      ✓ adds the investment to PT contract investments lookup
      context: when more assets are added
        ✓ distributes T tokens correctly (314ms)
        ✓ logs an equal allowance on all 3 VT contracts (47ms)
    context: un-even investments, all tokens with same cap
      ✓ invests T tokens appropriately by filling one while investing in others evenly (499ms)

Contract: PortfolioToken
  addInvestment()
    ✓ reverts if the investor does not have PT tokens
    ✓ reverts if the contract does not have the specified VT tokens (69ms)
    ✓ adds the investment to lookup table
  claimFundsAndBurn()
    context: only one investor
      ✓ gets correct data from getCurrentOwnershipPercentage()
      ✓ gets correct data from calculateTotalProjectedValueOwned()
      ✓ gets correct data from calculateTotalCurrentValueOwned() (38ms)
      ✓ reverts when the sender does not have PT tokens
      ✓ reverts when the sender has less PT tokens than they attempt to redeem (43ms)
      ✓ transfers VT tokens to the investor proportionate to their PT ownership (111ms)
      ✓ burns the investor's PT tokens
      ✓ updates the investment lookup table

Contract: VehicleToken
  constructor()
    ✓ initializes storage variables (77ms)
  getProjectedProfit()
    ✓ reverts if the caller does not have an investment (86ms)
    ✓ calculates the projected profit given the number of tokens the investor owns (128ms)
  getCurrentProfit()
    ✓ reverts if the caller does not have an investment (83ms)
    ✓ calculates the profit the investor would receive if they cashed out now (141ms)
  getCurrentValuePortfolio()
    ✓ reverts if the caller does not have an investment (86ms)
    ✓ calculates the total value of the asset + its current profit (183ms)
  claimFundsAndBurn()
    ✓ reverts if the caller does not have an investment (42ms)
    ✓ does NOT call selfdestruct when there are tokens left to redeem (267ms)
    context: HACKY
      ✓ transfers profit T tokens to the investor and burns their VT tokens - HACKY (177ms)
      ✓ calls selfdestruct() when there are no tokens left (everyone has claimed their funds)


48 passing (10s)

Migrate to your local blockchain

Make sure you run ganache-cli in one terminal