pytest-cairo 0.0.3

Pytest support for cairo-lang and starknet

pytest-cairo: pytest support for cairo-lang and starknet

Usage

To install:

$ pip install pytest-cairo

The plugin will automatically run any function with a test prefix, from files with a test_ prefix and a .cairo extension.

Example

Consider the following Starknet contract:

# Contents of contract.cairo
%lang starknet

from starkware.cairo.common.cairo_builtins import HashBuiltin

func calculate_inverse{
    syscall_ptr : felt*,
    pedersen_ptr : HashBuiltin*,
    range_check_ptr,
}(val : felt) -> (res : felt):
    return (1 / val)
end

We could write a basic test for the function calculate_inverse:

# Contents of test_contract.cairo
%lang starknet

from starkware.cairo.common.cairo_builtins import HashBuiltin

from contracts.contract import calculate_inverse

@external
func test_calculate_inverse{
    syscall_ptr : felt*,
    pedersen_ptr : HashBuiltin*,
    range_check_ptr,
}() -> ():
    let (actual) = calculate_inverse(2)
    let expected = 1 / 2
    assert actual = expected
    return ()
end

Additionally we could use a raises attribute to assert that the function fails if we pass val=0:

@external
func test_calculate_inverse_expected_exception{
    syscall_ptr : felt*,
    pedersen_ptr : HashBuiltin*,
    range_check_ptr,
}() -> ():
    with_attr raises("assert_not_zero failed"):
        calculate_inverse(0)
    end
    return ()
end

Development

To install development dependencies, run:

$ pip install -r requirements-dev.txt

Run tests with:

$ pytest

or:

$ docker-compose run test

To run tests against all supported interpreters (using docker-compose):

$ tox

This assumes tox, docker and docker-compose are installed.