Assignment

Overview

This submission extends the Hyperledger Besu codebase to support reading and testing a new private mutable variable (epochCounter) in the validator_contract.sol smart contract, as per the assignment requirements.

What Was Done

1. Smart Contract Update

   • Modified validator_contract.sol to add a private mutable variable epochCounter with a public getter (getEpochCounter) and setter (setEpochCounter).

2. Contract Compilation

   • Compiled the updated Solidity contract to generate the ABI and binary for integration with Besu.

3. Client Modification

   • Extended the ValidatorContractController Java class to:
     • Add support for reading the epochCounter value from the contract.
     • Implement robust error handling and function-specific decoding for both getValidators and getEpochCounter.

4. Unit Tests

   • Added and updated tests in ValidatorContractControllerTest to:
     • Verify correct reading of the epochCounter value.
     • Ensure proper error handling for all edge cases (failed/invalid/empty simulation results, unexpected types, etc.) for both getValidators and getEpochCounter.

Notes

• All changes are isolated to the contract, controller, and test files as required.

To run locally

Clone the repo locally, and then

• The tests can be run locally by running:

# from the root of the project
./gradlew :consensus:qbft:test --tests "org.hyperledger.besu.consensus.qbft.validator.ValidatorContractControllerTest"

• The smart ocntract can be compiled by:

# assumes you are in the root of this project and have solc installed
$: cd consensus/qbft-core/src/integration-test/resources
$: solc --bin --abi validator_contract.sol -o build

• Optionally to ensure code style was maintained, the linter can be run using the following command:

./gradlew spotlessApply

The rest of the original readme can be found at: https://github.com/hyperledger/besu