Spawner (eip1167-spawner)

Spawn EIP 1167 minimal proxies with an included initialization step during contract creation.

These contracts demonstrate a technique for initializing and deploying EIP 1167 minimal proxies that point to designated logic contracts. Logic contracts should make an initialization function available that only allows it to be called during contract construction (i.e. assembly { if extcodesize(address) { revert(0, 0) } }).

Table of Contents

• Install
• Usage
• Maintainers
• Contribute
• License

Install

To include Spawner as a dependency in your project:

$ yarn add eip1167-spawner

To install locally, you'll need Node.js 10+ and Yarn (or npm). To get everything set up:

$ git clone https://github.com/0age/Spawner.git
$ cd Spawner
$ yarn install
$ yarn build

Usage

Import Spawner and inherit it on a contract, then call _spawn with the desired logic contract and ABI-encoded initialization calldata:

pragma solidity ^0.5.0;

import "eip1167-spawner/contracts/Spawner.sol";
import "./MyLogicContract.sol";


contract MyFactory is Spawner {
  function spawnIt() public returns (address spawnedContract) {
    MyLogicContract logic = MyLogicContract(address(...));
    
    bytes memory myInitializationCalldata = abi.encodeWithSelector(
      logic.initialize.selector,
      "argumentOne",
      "argumentTwo"
    );
    
    spawnedContract =  _spawn(
      address(logicContract),
      myInitializationCalldata
    );
  }
}

You can also use _spawnCompact (for logic contracts with at least five leading zero bytes or ten zeroes), _spawnOldSchool (for deploying with CREATE rather than CREATE2), or _spawnCompactOldSchool. In addition, you can compute addresses spawned with CREATE2 ahead of time by using the supplied _computeNextAddress and _computeNextCompactAddress internal view functions.

Note: Spawner will be careful not to deploy to any address that already has code at it, but watch out - if the code that the minimal proxy points to can cause a SELFDESTRUCT, it is possible that Spawner may redeploy a minimal proxy to an address it has already deployed to in the past. This may or may not be the intended behavior, so feel free to put in extra safeguards if you're worried about this.

To run tests locally, start the testRPC, trigger the tests, and tear down the testRPC (you can do all of this at once via yarn all if you prefer):

$ yarn start
$ yarn test
$ yarn stop

Maintainers

@0age

Contribute

PRs accepted gladly - make sure the tests pass. (Changes to the contracts themselves should bump the version number and be marked as pre-release.)

License

MIT © 2019 0age