python-tdd/src/apps/dashboard/tests/test_forms.py

from django.test import TestCase
from ..forms import (
    DUPLICATE_ITEM_ERROR,
    EMPTY_ITEM_ERROR,
    ExistingListItemForm,
    ItemForm,
)
from ..models import Item, List

class ItemFormTest(TestCase):
    def test_form_validation_for_blank_items(self):
        form = ItemForm(data={"text": ""})
        self.assertFalse(form.is_valid())
        self.assertEqual(form.errors["text"], [EMPTY_ITEM_ERROR])

    def test_form_save_handles_saving_to_a_list(self):
        mylist = List.objects.create()
        form = ItemForm(data={"text": "do re mi"})
        self.assertTrue(form.is_valid())
        new_item = form.save(for_list=mylist)
        self.assertEqual(new_item, Item.objects.get())
        self.assertEqual(new_item.text, "do re mi")
        self.assertEqual(new_item.list, mylist)

class ExistingListItemFormTest(TestCase):
    def test_form_validation_for_blank_items(self):
        list_ = List.objects.create()
        form = ExistingListItemForm(for_list=list_, data={"text": ""})
        self.assertFalse(form.is_valid())
        self.assertEqual(form.errors["text"], [EMPTY_ITEM_ERROR])

    def test_form_validation_for_duplicate_items(self):
        list_ = List.objects.create()
        Item.objects.create(list=list_, text="twins, basil")
        form = ExistingListItemForm(for_list=list_, data={"text": "twins, basil"})
        self.assertFalse(form.is_valid())
        self.assertEqual(form.errors["text"], [DUPLICATE_ITEM_ERROR])

    def test_form_save(self):
        mylist = List.objects.create()
        form = ExistingListItemForm(for_list=mylist, data={"text": "howdy"})
        self.assertTrue(form.is_valid())
        new_item = form.save()
        self.assertEqual(new_item, Item.objects.get())