expect_call

def expect_call(self, contract_address: int, fn_name: str, calldata: list[int]) -> None: ...

Allows specifying what calls to contracts' functions are expected in the code. It sets an expectation for a specific call that is then checked either when the returned callable is called or at the end of the current scope.

calldata is a list of arguments that are expected for a certain call. The checking mechanism goes for a strict match, which means that the order, as well as the values of each element, have to be exactly the same.

Example

%lang starknet

@contract_interface
namespace MainContract {
  func increase_balance(amount_1: felt, amount_2: felt, amount_3: felt) -> () {
  }
}

@external
func __setup__() {
  %{
    context.ctr_addr_a = deploy_contract("basic_contract.cairo", []).contract_address
    context.ctr_addr_b = deploy_contract("basic_contract.cairo", []).contract_address
  %}

  return ();
}


@external
func test_expect_call_success{syscall_ptr: felt*, range_check_ptr}() {
  tempvar ctr_addr_a;
  %{ ids.ctr_addr_a = context.ctr_addr_a %}
  tempvar ctr_addr_b;
  %{ ids.ctr_addr_b = context.ctr_addr_b %}

  %{ assert_increase_balance_a_567_called = expect_call(ids.ctr_addr_a, "increase_balance", [5, 6, 7]) %}
  %{ assert_increase_balance_b_123_called = expect_call(ids.ctr_addr_b, "increase_balance", [1, 2, 3]) %}

  MainContract.increase_balance(contract_address=ctr_addr_a, amount_1=5, amount_2=6, amount_3=7);
  %{ assert_increase_balance_a_567_called() %}

  MainContract.increase_balance(contract_address=ctr_addr_b, amount_1=1, amount_2=2, amount_3=3);

  return ();
}

@external
func test_expect_call_fail_after_stop{syscall_ptr: felt*, range_check_ptr}() {
  tempvar ctr_addr_a;
  %{ ids.ctr_addr_a = context.ctr_addr_a %}

  %{ assert_increase_balance_a_567_called = expect_call(ids.ctr_addr_a, "increase_balance", [5, 6, 7]) %}
  %{ assert_increase_balance_a_567_called() %}

  MainContract.increase_balance(contract_address=ctr_addr_a, amount_1=5, amount_2=6, amount_3=7);

  return ();
}

@external
func test_expect_call_wrong_args{syscall_ptr: felt*, range_check_ptr}() {
  tempvar ctr_addr_a;
  %{
    ids.ctr_addr_a = context.ctr_addr_a
    expect_call(ids.ctr_addr_a, "increase_balance", [1, 3, 2])
  %}

  MainContract.increase_balance(contract_address=ctr_addr_a, amount_1=1, amount_2=2, amount_3=3);

  return ();
}

test_expect_call_wrong_args will fail because even though the set of expected arguments is the same as the arguments in the call, the order is different, so they do not strictly match.