Test a custom filter in admin.py

Question

I've the following filter in my admin.py file:

class parentCategoryFilter(admin.SimpleListFilter):
    title = 'parent category'
    parameter_name = 'parent_category'

    def lookups(self, request, model_admin):
        first_level_categories = model_admin.get_queryset(request).filter(parent_category__isnull=True)

        if first_level_categories:

            lookups = (('none', 'None'),)

            for first_level_category in first_level_categories:
                lookups += ((first_level_category.id, first_level_category.name),)

            return lookups

    def queryset(self, request, queryset):
        if self.value() == 'none':
            return queryset.filter(parent_category__isnull=True)
        elif self.value():
            try:
                return queryset.filter(parent_category=int(self.value()))
            except (ValueError, TypeError):
                return queryset.none()
        else:
            pass

And I want to test it in my tests.py file, however while trying to instantiate the class it starts asking me about 5 __init__ parameters. Is it possible to test this filter functionality?

Answer 1

The 5 parameters that __init__ needs is from admin.SimpleListFilter whose __init__ is defined as: (Source)

def __init__(self, request, params, model, model_admin):

You can pass in those parameters to test your filter