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 Deposit instead of Transfer from address(0) when minting and Withdrawal instead of Transfer to address(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 truffle

Tests

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)