LZOneWayMigration

Contracts to perform migration of any ERC20 token to other chain using Layer Zero network.

Users will send their ERC20 tokens to Burner contract on source chain, and through LayerZero, Minter contract on destination chain will be called thus calling mint() of your new ERC20.

Deployment

0. Create .env file based on .env.example file.

1. Install dependencies, compile contracts, and run tests:

   yarn && npx hardhat test

2. On the source chain (where your ERC20) is located, deploy Burner contract:

   npx hardhat --network <burner-network> deploy --tags Burner

3. On the destination chain, deploy your new ERC20 token implementing IMintable.

4. On the destination chain, deploy Minter contract (make sure Minter can call mint() of your new ERC20):

   npx hardhat --network <minter-network> deploy --tags Minter

5. Run setTrsutedRemotes task:

   1. npx hardhat --network <burner-network> setTrustedRemote --target-network <minter-netowrk> --local-contract Burner --remote-contract Minter

   2. npx hardhat --network <minter-network> setTrustedRemote --target-network <burner-netowrk> --local-contract Minter --remote-contract Burner

6. (Optional) verify with:

   npx hardhat --network <network> etherscan-verify --api-key <api-key>

7. Unpause Burner contract to enable migrating:

   npx hardhat --network <burner-network> pause --unpause

Migration

1. Approve amount of ERC20 to migrate to Burner contract.

2. Call estimateFee() of Burner contract.

3. Call migrate() of Burner contract, with fee copied from estimateFee() output.

   Also msg.value in native tokens should match fee.

4. Copy tx hash, and check your migration on LayerZero Scan

5. If message Status is Delivered, but Destination transaction error is Stored payload, refer to troubleshooting down below, otherwise migration should be succesfull.

You can also listen for MigrationStarted and MigrationFinished events.

Troubleshooting

No network in hardhat

Update hardhat.confid.ts with new networks if needed.

PayloadStored error in LayerZero Scan

It should only happen if mint() function of your new ERC20 reverts, eg. by being Paused. It will block all further migrations until you unblock mint() function and retry message. You can check <amount> and <user-address> in MigrationStarted event of Burner contract, with nonce same as one with PayloadStored in LayerZero Scan Example.

`npx hardhat --network <minter-network> retryPayload --amount <amount> --user <user-address> --source-chain <burner-network>`