Improved Canonical Wrapped Ether
This contract is an improvement to the Canonical W-ETH package (original post here https://blog.0xproject.com/canonical-weth-a9aa7d0279dd).
Description
Canonical Wrapped Ether (WETH9, 0xc02aaa39b223fe8d0a0e5c4f27ead9083c756cc2) has at least two major flaws:
- You can lock your WETH in the contract (at 2022.05.29, they are ~644 ethers and counting)
- You cannot recover other tokens sent to this contract
It has one minor issue as well:
- It uses a custom event for minting, so it emits
Depositinstead ofTransferfromaddress(0)when minting andWithdrawalinstead ofTransfertoaddress(0)when burning tokens. Not too big an issue indeed, but the contract wants to be a standard EIP20 token, so better to avoid custom events.
Wrapped Ether 911 fixes those flaws:
- You cannot send WETH911 to the contract (tx reverts)
- Anyone can recover lost tokens assigned to this contract (happy front running to everybody ^^)
- The contract emits {Transfer} events when minting or burning WETH911
Deployed contract addresses
- Mainnet: 0x6be7ef70b35fdb9042d704c920d003b414385c76
- Goerli: 0x1989920574186c5564f89850740b5181770f599f
- Kovan: 0x914179daf1e1edcd052eb4096a622fbabaa37a8b
- Ropsten: 0x7c44b54fc7da66d50e39799be22caba38ac60d94
- Rinkeby: 0xb31700e30f03a0a1c54411f54cb5d5ac94a80ab8
Setup
You need Truffle to run tests for this smart contract:
npm install -g truffleTests
To test the smart contract run:
$ truffle test
Using network 'test'.
Compiling your contracts...
===========================
> Compiling .\contracts\Migrations.sol
> Compiling .\contracts\WETH911.sol
> Compiled successfully using:
- solc: 0.8.14+commit.80d49f37.Emscripten.clang
Contract: WETH911
✔ should start without tokens
✔ should not be able to send WETH911 tokens (1341ms)
✔ should mint tokens (1085ms)
✔ should not allow the contract to receive WETH911 (1119ms)
✔ should transfer tokens (1189ms)
✔ should burn tokens and get ethers back (1092ms)
6 passing (6s)