You can create the payload for your Inline Formset Factory forms and utilise to Unit Test your Django forms.

formset_payload_gen.py

def build_formset_form_data(self, form_number, **data):
    form = {}
    for key, value in data.items():
        form_key = f"form-{form_number}-{key}"
        form[form_key] = value
    return form


def build_formset_data(self, forms, **common_data):
    formset_dict = {
        "form-TOTAL_FORMS": f"{len(forms)}",
        "form-MAX_NUM_FORMS": "1000",
        "form-INITIAL_FORMS": "1"
    }
    formset_dict.update(common_data)
    for i, form_data in enumerate(forms):
        form_dict = self.build_formset_form_data(form_number=i, **form_data)
        formset_dict.update(form_dict)
    return formset_dict