pezkuwi-subxt/bridges/snowbridge/parachain/README.md

Parachain modules

Configuration

Note: This section is not necessary for local development, as there are scripts to auto-configure the parachain in the test directory.

For a fully operational chain, further configuration of the initial chain spec is required. The specific configuration will depend heavily on your environment, so this guide will remain high-level.

After completing a release build of the parachain, build an initial spec for the snowbase runtime:

target/release/snowbridge build-spec --chain snowbase --disable-default-bootnode > spec.json

Now edit the spec and configure the following:

1. Recently finalized ethereum header and difficulty for the ethereum light client
2. Contract addresses for the Ether, Erc20, and Dot apps.
3. Authorized principal for the basic channel

For an example configuration, consult the setup script for our local development stack. Specifically the start_polkadot_launch bash function.

Tests

To run the parachain tests locally, use cargo test --workspace. For the full suite of tests, use cargo test --workspace --features runtime-benchmarks.

Optionally exclude the top-level and runtime crates:

cargo test --workspace \
        --features runtime-benchmarks \
        --exclude snowbridge \
        --exclude snowbridge-runtime \
        --exclude snowblink-runtime \
        --exclude snowbase-runtime

Updating test data for inbound channel unit tests

To regenerate the test data, use a test with multiple submit calls in ethereum/test/test_basic_outbound_channel.js, eg. "should increment nonces correctly".

Add the following preamble:

const rlp = require("rlp");
const contract = BasicOutboundChannel;
const signature = 'Message(address,address,uint64,uint64,bytes)';

For each encoded log you want to create, find a transaction object tx returned from a submit call and run this:

const rawLog = tx.receipt.rawLogs[0];
const encodedLog = rlp.encode([rawLog.address, rawLog.topics, rawLog.data]).toString("hex");
console.log(`encodedLog: ${encodedLog}`);
const iface = new ethers.utils.Interface(contract.abi);
const decodedEventLog = iface.decodeEventLog(
  signature,
  rawLog.data,
  rawLog.topics,
);
console.log(`decoded rawLog.data: ${JSON.stringify(decodedEventLog)}`);

Place the encodedLog string in the message.data field in the test data. Use the decoded rawLog.data field to update the comments with the decoded log data.

Generating pallet weights from benchmarks

Build the parachain with the runtime benchmark flags for the chosen runtime:

runtime=snowbase
cargo build \
    --release \
    --no-default-features \
    --features "$runtime-native,rococo-native,runtime-benchmarks,$runtime-runtime-benchmarks" \
    --bin snowbridge

List available pallets and their benchmarks:

./target/release/snowbridge benchmark pallet --chain $runtime --list

Run a benchmark for a pallet, generating weights:

target/release/snowbridge benchmark pallet \
  --chain=$runtime \
  --execution=wasm \
  --wasm-execution=compiled \
  --pallet=basic_channel_inbound \
  --extra \
  --extrinsic=* \
  --repeat=20 \
  --steps=50 \
  --output=pallets/basic-channel/src/inbound/weights.rs \
  --template=templates/module-weight-template.hbs

Generating beacon test fixtures and benchmarking data

Minimal Spec

To generate minimal test data and benchmarking data, make sure to start the local E2E setup to spin up a local beacon node instance to connect to:

cd web/packages/test
./scripts/start-services.sh

Wait for output Testnet has been initialized.

In a separate terminal, from the snowbridge directory, run:

mage -d relayer build && relayer/build/snowbridge-relay generate-beacon-data --spec "minimal" && cd parachain &&
cargo +nightly fmt -- --config-path rustfmt.toml && cd -

Mainnet Spec

We only use the mainnet spec for generating fixtures for pallet weight benchmarks.

To generate the data we can connect to the Lodestar Goerli public node. The script already connects to the Lodestar node, so no need to start up additional services. In the event of the Lodestar node not being available, you can start up your own stack with these commands:

cd web/packages/test
./scripts/start-goerli.sh

From the snowbridge directory, run:

mage -d relayer build && relayer/build/snowbridge-relay generate-beacon-data --spec "mainnet" && cd parachain &&
cargo +nightly fmt -- --config-path rustfmt.toml && cd -

Benchmarking tests

To run the benchmark tests

cd parachain/pallets/ethereum-beacon-client
cargo test --release --features runtime-benchmarks