test_main.cairo

%lang starknet
from src.main import balance, increase_balance
from starkware.cairo.common.cairo_builtins import HashBuiltin

@external
func test_increase_balance{syscall_ptr: felt*, range_check_ptr, pedersen_ptr: HashBuiltin*}() {
    let (result_before) = balance.read();
    assert result_before = 0;

    increase_balance(42);

    let (result_after) = balance.read();
    assert result_after = 42;
    return ();
}

@external
func test_cannot_increase_balance_with_negative_value{
    syscall_ptr: felt*, range_check_ptr, pedersen_ptr: HashBuiltin*
}() {
    let (result_before) = balance.read();
    assert result_before = 0;

    %{ expect_revert("TRANSACTION_FAILED", "Amount must be positive") %}
    increase_balance(-42);

    return ();
}