TestBridge abstract

Here we check functionality of Matic POST Bridge.

Description

Deploy token on L1

Reference: https://docs.matic.network/docs/develop/ethereum-matic/mintable-assets

We took contracts/root/RootToken/DummyMintableERC20.sol and edited it to SxrTokenL1.sol. Minting is optional, for production we'll not mint anything on L1.

The we granted PREDICATE_ROLE to "MintableERC20PredicateProxy" ( "0x37c3bfC05d5ebF9EBb3FF80ce0bd0133Bf221BC8" ).

Verify the contract with etherscan plugin.

Deploy token on L2

We used https://github.com/maticnetwork/pos-portal/blob/master/contracts/child/ChildToken/ChildMintableERC20.sol

and modified to SxrTokenL2.sol. We added burn() function to simulate the one from real project.

Verify on Matic explorer: https://explorer-mumbai.maticvigil.com/

Only flatten contracts can be verified, imports are not supported. Use https://abi.hashex.org/ tpo encode constructor params.

Make sure optimization run number fits exactly on hardhat and verifier page.

Map on the bridge

Use https://mapper.matic.today/

Checking L2->L1 transfer

scripts/fromMaticSDK.js does not work as exitERC20() never detects that transaction is mined on the L1. I kept this script just as a reference.

scripts/fromMatic.js does work, we use contact callings and exitERC20() is used to get exit data only.

scripts/fromMaticWithRepeat.js is as fromMatic.js but with repeat function in the case of transaction being not confirmed.

Calling fromMaticSDK.js:

> node scripts/fromMaticSDK.js

Calling fromMatic.js:

> npx hardhat --network mumbai run scripts/fromMatic.js

We use hardhat to run this script though we could refactor to not use it. We set 15 minutes to wait for the burn transaction to be validated with exitERC20() function.

Checking L1->L2 transfer

scripts/toMaticSDK.js works ok with SDK.

Note

SDK does not accept bignumbers from ethers.utils.parseEther('1000').

Checking burning on L2

We added burn function on the L2 token contract. Test with

> npx hardhat --network mumbai run scripts/burnOnMatic.js

Possible errors

The test network RPC can be down for some time (~2 hours), don't give up. Wait and try again. The error indicating there are problems on RPC is

PollingBlockTracker - encountered an error while attempting to update latest block

Ref: https://www.gitmemory.com/issue/trufflesuite/truffle/3356/780754223

References

https://docs.matic.network/docs/develop/ethereum-matic/pos/deployment https://abi.hashex.org/