play collateral token

An implementation of a "play money" collateral token for use with ConditionalTokens.

overview

This repository provides a restrictive "play money" ERC20 token called PlayCollateralToken, along with a PlayCollateralTokenFactory that can deploy instances of it. The token only allows transfers from or to:

• The owner (who initially receives all tokens),
• The ConditionalTokens contract, but only when initiated by the ConditionalTokens contract itself.

This ensures no free trading occurs—tokens can’t flow to arbitrary addresses or be traded on DEXes.

how the token works

• Constructor: Mints an initial supply of tokens to the OWNER.
• Transfer Restrictions:
  • Transfers from OWNER to CONDITIONAL_TOKENS are allowed.
  • Transfers from CONDITIONAL_TOKENS to OWNER are allowed (only when the contract calls transferFrom).
  • Any other transfers revert with an InvalidPlayTokenTransfer error.
• Minting & Burning:
  • Minting occurs in the constructor (or if you extend the logic).
  • Burning can be simulated by sending tokens back to OWNER or possibly making additional logic if needed.

using the factory

1. Deploy PlayCollateralTokenFactory by passing it the address of the ConditionalTokens contract you want to trust.
2. Call createCollateralToken(name, symbol, initialSupply, owner) on the factory:
   • name: A string for the ERC20 name.
   • symbol: A string for the ERC20 ticker.
   • initialSupply: The amount of tokens to mint to the owner.
   • owner: The address that will control and distribute tokens.

The factory will emit an event PlayCollateralTokenCreated(address token) and return the new token address.

PlayCollateralToken tests

The outcome of a transfer depends on three parameters:

• from
• to
• msg.sender

Unit tests cover every combination:

• When any of from or to is the OWNER.
• When from is CONDITIONAL_TOKENS.
• When to is CONDITIONAL_TOKENS:
  • When msg.sender is CONDITIONAL_TOKENS.
  • Otherwise (reverts).
• Otherwise (reverts).

Additional integration test verify that the transfer and transferFrom ERC20 calls work as expected.

deployment

Using Foundry:

1. Set environment variables (RPC_URL, SENDER, PRIVATE_KEY) for your deployer account.
2. Set environment variables expected by the deployment script: CONDITIONAL_TOKENS, the address of the existing ConditionalTokens deployment.
3. Run the deployment script:

   forge script script/DeployFactory.s.sol \
     --rpc-url $RPC_URL \
     --broadcast \
     --sender $SENDER \
     --private-key $PRIVATE_KEY

building and testing

forge soldeer install
forge build
forge test