import json
import django
from django.test import SimpleTestCase
from django.core.exceptions import ValidationError

from ..widgets import JSignatureWidget
from ..forms import JSignatureField


class JSignatureFormFieldTest(SimpleTestCase):

    def test_widget(self):
        f = JSignatureField()
        self.assertIsInstance(f.widget, JSignatureWidget)

    def test_to_python(self):
        f = JSignatureField()
        # Empty values
        for val in ['', [], '[]']:
            self.assertIsNone(f.to_python(val))
        # Correct values
        val = '[{"x":[1,2], "y":[3,4]}]'
        self.assertEquals([{'x':[1,2], 'y':[3,4]}], f.to_python(val))
        # Incorrect values
        val = 'foo'
        self.assertRaises(ValidationError, f.to_python, val)