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pytest-plugin: crosszip_parametrize

pytest_generate_tests(metafunc)

Generate parametrized tests using the cross-product of parameter values.

This pytest hook parametrizes tests based on the crosszip_parametrize marker. It extracts parameter names and their corresponding lists of values, computes their Cartesian product, and parametrizes the test function accordingly.

Parameters:

Name Type Description Default
metafunc Metafunc

The test function's metadata provided by pytest.

 required

Raises:

Type Description
ValueError

If parameter names and values are not provided or their lengths do not match.
TypeError

If parameter names are not strings or parameter values are not non-empty sequences.
Example 
import math
import crosszip
import pytest

@pytest.mark.crosszip_parametrize(
    "base",
    [2, 10],
    "exponent",
    [-1, 0, 1],
)
def test_power_function(base, exponent):
    result = math.pow(base, exponent)
    assert result == base ** exponent
Source code in src/crosszip/plugin.py 
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def pytest_generate_tests(metafunc: pytest.Metafunc) -> None:
    """Generate parametrized tests using the cross-product of parameter values.

    This pytest hook parametrizes tests based on the `crosszip_parametrize` marker.
    It extracts parameter names and their corresponding lists of values, computes their
    Cartesian product, and parametrizes the test function accordingly.

    Args:
        metafunc (pytest.Metafunc): The test function's metadata provided by pytest.

    Raises:
        ValueError: If parameter names and values are not provided or their lengths do not match.
        TypeError: If parameter names are not strings or parameter values are not non-empty sequences.

    Example:
        ```python
        import math
        import crosszip
        import pytest

        @pytest.mark.crosszip_parametrize(
            "base",
            [2, 10],
            "exponent",
            [-1, 0, 1],
        )
        def test_power_function(base, exponent):
            result = math.pow(base, exponent)
            assert result == base ** exponent
        ```

    """
    marker = metafunc.definition.get_closest_marker("crosszip_parametrize")
    if marker:
        args = marker.args
        param_names = args[::2]
        param_values = args[1::2]

        if not param_names or not param_values:
            raise ValueError("Parameter names and values must be provided.")
        if len(param_names) != len(param_values):
            raise ValueError(
                "Each parameter name must have a corresponding list of values.",
            )

        if not all(isinstance(name, str) for name in param_names):
            raise TypeError("All parameter names must be strings.")

        if any(
            not isinstance(values, Sequence) or not values for values in param_values
        ):
            raise TypeError("All parameter values must be non-empty sequences.")

        combinations = list(product(*param_values))
        param_names_str = ",".join(param_names)
        metafunc.parametrize(param_names_str, combinations)