I am very pleased to announce this new version of `pytest-cases`, providing a lot of **major** improvements. Creating powerful and complex test suites have never been so easy and intuitive !
Below is a complete list of changes, but the user guide has also been updated accordingly so feel free to [have a look](index.md) to get a complete example-based walkthrough.
**A/ More powerful and flexible cases collection**
New [`parametrize_with_cases`](./api_reference.mdparametrize_with_cases) decorator to replace `cases_data` (deprecated).
1. Aligned with `pytest`:
- now `argnames` can contain several names, and the case functions are **automatically unpacked** into it. You don't need to perform a `case.get()` in the test anymore !
parametrize_with_cases("a,b")
def test_foo(a, b):
use a and b directly !
...
- cases are unpacked at test *setup* time, so *the clock does not run while the case is created* - in case you use `pytest-harvest` to collect the timings.
- `parametrize_with_cases` can be used on test functions *as well as fixture functions* (it was already the case in v1)
2. Easier to configure:
- the decorator now has a single `cases` argument to indicate the cases, wherever they come from (no `module` argument anymore)
- default (`cases=AUTO`) *automatically looks for cases in the associated case module* named `test_xxx_cases.py`. Users can easily switch to alternate pattern `cases_xxx.py` with `cases=AUTO2`. Fixes [91](https://github.com/smarie/python-pytest-cases/issues/91).
- **cases can sit inside a class**, like [what you're used to do with `pytest`](https://docs.pytest.org/en/stable/getting-started.html#group-multiple-tests-in-a-class). This additional style makes it much more convenient to organize cases and associated them with tests, when cases sit in the same file than the tests. Fixes [93](https://github.com/smarie/python-pytest-cases/issues/93).
- an explicit sequence can be provided, *it can mix all kind of sources*: functions, classes, modules, and *module names as strings* (even relative ones!).
parametrize_with_cases("a", cases=(CasesClass, '.my_extra_cases'))
def test_foo(a):
...
3. More powerful API for filtering:
- a new `prefix` argument (default `case_`) can be used to define case functions for various type of parameters: welcome `user_<id>`, `data_<id>`, `algo_<id>`, `model_<id>` ! Fixes [108](https://github.com/smarie/python-pytest-cases/issues/108)
- a new `glob` argument receiving a glob-like string can be used to further filter cases based on their names. For example you can distinguish `*_success` from `*_failure` case ids, so as to dispatch them to the appropriate positive or negative test. Fixes [108](https://github.com/smarie/python-pytest-cases/issues/108)
- finally you can still use `has_tag` and/or provide a `filter` callable, but now the callable will receive the case function, and this case function has a `f._pytestcase` attribute containing the id, tags and marks - it is therefore much easier to implement custom filtering.
**B/ Easier-to-define case functions**
- Case functions can start with different prefixes to denote different kind of data: e.g. `data_<id>`, `user_<id>`, `model_<id>`, etc.
- Case functions can now be parametrized with [`parametrize`](pytest_goodies.mdparametrize) or `pytest.mark.parametrize`, just as in pytest ! This includes the ability to put [`pytest` marks](https://docs.pytest.org/en/stable/mark.html) on the whole case, or on some specific parameter values using [`pytest.param`](https://docs.pytest.org/en/stable/example/parametrize.html#set-marks-or-test-id-for-individual-parametrized-test). `cases_generator` is therefore now deprecated but its alternate style for ids and arguments definition was preserved in `parametrize`, see below.
- Now case functions can require fixtures ! In that case they will be transformed into fixtures and injected as `fixture_ref` in the parametrization. Fixes [56](https://github.com/smarie/python-pytest-cases/issues/56).
- New single optional `case(id=None, tags=(), marks=())` decorator to replace `case_name` and `case_tags` (deprecated): a single simple way to customize all aspects of a case function. Also, `test_target` completely disappears from the picture as it was just a tag like others - this could be misleading.
**C/ Misc / pytest goodies**
- New aliases for readability: `fixture` for `fixture_plus`, and`parametrize` for `parametrize_plus` (both aliases will coexist with the old names). Fixes [107](https://github.com/smarie/python-pytest-cases/issues/107).
- `parametrize` was improved in order to support the alternate parametrization mode that was previously offered by `cases_generator`, see [api reference](api_reference.mdparametrize). That way, users will be able to choose the style of their choice. Fixes [57](https://github.com/smarie/python-pytest-cases/issues/57) and [#106](https://github.com/smarie/python-pytest-cases/issues/106).
- `parametrize` now raises an explicit error message when the user makes a mistake with the argnames. Fixes [105](https://github.com/smarie/python-pytest-cases/issues/105).
- More readable error messages in `parametrize` when `lazy_value` does not return the same number of argvalues than expected from the argnames.
- Any error message associated to a `lazy_value` function call is not caught and hidden anymore but is emitted to the user, for easier debugging.
- Fixed issue with `lazy_value` when a single mark is passed in the constructor.
- `lazy_value` used as a tuple for several arguments now have a correct id generated even in old pytest version 2.
- New pytest goodie `assert_exception` that can be used as a context manager. Fixes [104](https://github.com/smarie/python-pytest-cases/issues/104).
See [documentation page](https://smarie.github.io/python-pytest-cases/changelog/) for details.