Crate mavryk_smart_rollup_mock

Mock runtime provides a host that can used in integration & unit testing of kernels for Mavryk Smart Rollups.

To do so, MockHost implements the SmartRollupCore trait - allowing it to be passed as an argument to any function, where the argument is required to implement either SmartRollupCore or Runtime.

Example

Take a simple kernel that will count the number of times it is called, rebooting at most 500 times per level.

use mavryk_smart_rollup_mock::MockHost;
use mavryk_smart_rollup_host::runtime::Runtime;
use mavryk_smart_rollup_host::path::RefPath;

const COUNTER_PATH: RefPath = RefPath::assert_from(b"/counter");
const COUNTER_SIZE: usize = core::mem::size_of::<u32>();

// Kernel entrypoint, to count the number of times called.
// After 1000 calls at a given level, will restart at the
// next level.
fn count_calls<Host: Runtime>(host: &mut Host) {
  let mut counter = read_counter(host);

  counter += 1;

  // A kernel can reboot up to 1000 times per level.
  if counter % 1000 != 0 {
    host.mark_for_reboot().expect("Marking for reboot failed.");
  }

  host.store_write(&COUNTER_PATH, &counter.to_le_bytes(), 0)
      .expect("Failed to write counter to storage.")
}

// Reads `COUNTER_PATH` as `u32` in little-endian.
// - returns 0 if counter does not exist.
fn read_counter(host: &impl Runtime) -> u32 {
  host.store_read(&COUNTER_PATH, 0, COUNTER_SIZE)
      .map(|bytes| bytes.try_into().unwrap_or_default())
      .map(u32::from_le_bytes)
      .unwrap_or_default()
}

// Run using mock host - every `run_level` should increment
// counter by 500.
let mut host = MockHost::default();
assert_eq!(0, read_counter(&host));

host.run_level(count_calls);
assert_eq!(1000, read_counter(&host));

host.run_level(count_calls);
assert_eq!(2000, read_counter(&host));

Structs

InMemoryStore

Wrapper over Store which implements methods equivalent to the host storage functions. It is used for both MockHost and for RollupHostWithInMemoryStorage in the entrypoint crate.

MockHost

The runtime host when not running in wasm.

TransferMetadata

Specifies the sender & source of a message from an L1-contract.