hardhat-revive-node v0.0.5

hardhat-revive-node

Plugin for running a mock in-memory PolkaVM node.

Description

This plugin enables the usage of a local instance of the PolkaVM node for testing, as well as the usage of the hardhat network's forking option to fork a live chain using @acala-network/chopsticks and use the Polkadot-SDK eth-rpc-adapter to enable local testing.

Requirements

In order to use the plugin, it must be imported at the top of the hardhat.config file, in order to override the relevant hardhat tasks.

Both when connecting to a live chain endpoint and when forking one, it is required that the path to the eth-rpc-adapter binary is specified, unless the endpoint you are connecting to is Ethereum compatible, otherwise all the calls will fail.

The version of the eth-rpc-adapter binary must be compatible with the runtime of the chain you are connecting to, else you will receive the following error:

Metadata error: The generated code is not compatible with the node

Configuration of standalone node

We can run the node locally as either a fork of a live chain or using local binaries.

npx hardhat node-polkavm --fork wss://asset-hub-westend-rpc.dwellir.com 
\ --build-block-mode Instant
\ --adapter-binary-path /path/to/adapter 
\ --dev

When connecting to a live chain to use the --fork command or when running a local node you need to have the eth-rpc-adapter binary present and it's path defined in the --adapter-binary-path. When running the node standalone, you must either define the chain to fork or provide a binary path to the run the local node.

Pleaser refer to the CliCommands type to see the available configuration options.

NOTE Usage of absolute paths are recommended.

Configuration for testing

When used for testing you have two options, either provide the configuration inside the hardhat.config.{ts,js} file or provide the configuration through the cli arguments defined in the previous section.

To run the node you can run the node with:

npx hardhat node

Having specified previously polkavm: true in the config file, or just run:

npx hardhat node-polkavm

Which will also initiate the node.

You will encounter this error with tests that use certain helpers:

OnlyHardhatNetworkError: This helper can only be used with Hardhat Network. You are connected to 'localhost'.

Until now there's no way to avoid this, since there are certain rpc calls that are required to comply with hardhat's network spec and are not present yet in the node.

As long as polkavm is set to true, you can also run the tests directly using:

npx hardhat test

Which will start the node in a separate process and run the tests against it.

When using the config field, you must define the hardhat options, such as the following:

const config: HardhatUserConfig = {
  solidity: "0.8.28",
  networks: {
    hardhat: {
      polkavm: true,
      forking: {
        url: 'wss://westend-asset-hub-rpc.polkadot.io',
      },
      adapterConfig: {
        adapterBinaryPath: '../../polkadot-sdk/target/release/eth-rpc',
        dev: true
      }
    },
  }
};

In this example, since we are forking a live chain, we do not need to specify the node binary path.

Pleaser refer to the CommandArguments type to see the available configuration options.

Compatibility

Regarding hardhat compatibility, even though it's set as part of the hardhat type in the NetworksConfig type, it is not compatible with hardhat-only helpers, such as time and loadFixture from @nomicfoundation/hardhat-toolbox/network-helpers, due to the node missing some rpc calls necessary for these calls to work.

When running against a local node, or against a fork of the live chain, you must make sure that the binaries employed are compatible with eachother. In order to do this, you can check inside pallet revive's Cargo.toml in order to see which commit of the polkadot-sdk you should use to build the substrate-node and eth-rpc-adapter binaries. If there is a missmatch betwween these versions, deployment will fail with CodeRejected or Metadata error: The generated code is not compatible with the node.

Further compatibility limitations have not been found at this point.