Examples

To use cw-multi-test, you need to understand a few key concepts:

App: Represents the simulated blockchain application, tracking block height and time. You can modify the environment to simulate multiple blocks, using methods like app.update_block(next_block).
Mocking Contracts: You must mock or wrap contracts using ContractWrapper to test them within the multi-test environment.

Example: setting up and testing with cw-multi-test

Step 1: create a mock app

fn mock_app() -> App {    let env = mock_env();    let api = Box::new(MockApi::default());    let bank = BankKeeper::new();    App::new(api, env.block, bank, Box::new(MockStorage::new()))}

Step 2: mock and wrap contracts

pub fn contract_counter() -> Box<dyn Contract<Empty>> {    let contract = ContractWrapper::new(        execute,        instantiate,        query,    );    Box::new(contract)}

Step 3: store and instantiate the contract

let contract_code_id = router.store_code(contract_counter());let mocked_contract_addr = router    .instantiate_contract(contract_code_id, owner.clone(), &init_msg, &[], "counter", None)    .unwrap();

Step 4: execute and query the contract

let msg = ExecuteMsg::Increment {};let _ = router.execute_contract(    owner.clone(),    mocked_contract_addr.clone(),    &msg,    &[],).unwrap();let config_msg = QueryMsg::Count {};let count_response: CountResponse = router    .wrap()    .query_wasm_smart(mocked_contract_addr.clone(), &config_msg)    .unwrap();assert_eq!(count_response.count, 1);

Mocking third-party contracts, such as those from protocols like Terraswap or Anchor, can be challenging since these protocols often don't include the contract code in their Rust packages. However, you can create a thin mock of the service you interact with by implementing only the functions and queries you need.

Example

pub fn contract_ping_pong_mock() -> Box<dyn Contract<Empty>> {    let contract = ContractWrapper::new(        |deps, _, info, msg: MockExecuteMsg| -> StdResult<Response> {            match msg {                MockExecuteMsg::Receive(Cw20ReceiveMsg { sender: _, amount: _, msg }) => {                    let received: PingMsg = from_binary(&msg)?;                    Ok(Response::new()                        .add_attribute("action", "pong")                        .set_data(to_binary(&received.payload)?))                }            }        },        |_, _, msg: MockQueryMsg| -> StdResult<Binary> {            match msg {                MockQueryMsg::Pair {} => Ok(to_binary(&mock_pair_info())?),            }        },    );    Box::new(contract)}