# Various

## Using `pytest` fixtures

### Retrieve constants during tests

There is a fixture in `conftest.py` aptly named `parameters` making all the variables defined in `fdv.py` accessible for the
tests. So, please, add additional parameter / constant by editing the `fdv.py` file.

### Other

You can check the `conftest.py` file to see what other fixtures are available.

### Example

```python
from cellpy import prms

# using the ``parameters`` and the ``cellpy_data_instance`` fixtures.

def test_set_instrument_selecting_default(cellpy_data_instance, parameters):
    prms.Instruments.custom_instrument_definitions_file = parameters.custom_instrument_definitions_file
    cellpy_data_instance.set_instrument(instrument="custom")
```

## Adding another config parameter

1. Edit `prms.py`
2. Check / update the `internal_settings.py` file as well to ensure that copying /
   splitting `cellpy` objects behaves properly.
3. Check / update the `.cellpy_prms_default.conf` file

The relevant files are located in the `parameters` folder:

```batch
cellpy/
    parameters/
        .cellpy_prms_default.conf
        prms.py
        internal_settings.py
```

## Installing pyodbc on Mac without conda

If you do not want to use `conda`, you might miss a couple of libraries.

The easiest fix is to install `uniuxodbc` using `brew` as explained in
[Stack Overflow #54302793](https://stackoverflow.com/questions/54302793/dyld-library-not-loaded-usr-local-opt-unixodbc-lib-libodbc-2-dylib).