from django.db.models import CharField

from django.db.models.functions import LTrim, RTrim, Trim

from django.test import TestCase

from django.test.utils import register_lookup

from ..models import Author

class TrimTests(TestCase):

    def test_trim(self):

        Author.objects.create(name="  John ", alias="j")

        Author.objects.create(name="Rhonda", alias="r")

        authors = Author.objects.annotate(

            ltrim=LTrim("name"),

            rtrim=RTrim("name"),

            trim=Trim("name"),

        )

        self.assertQuerysetEqual(

            authors.order_by("alias"),

            [

                ("John ", "  John", "John"),

                ("Rhonda", "Rhonda", "Rhonda"),

            ],

            lambda a: (a.ltrim, a.rtrim, a.trim),

        )

    def test_trim_transform(self):

        Author.objects.create(name=" John  ")

        Author.objects.create(name="Rhonda")

        tests = (

            (LTrim, "John  "),

            (RTrim, " John"),

            (Trim, "John"),

        )

        for transform, trimmed_name in tests:

            with self.subTest(transform=transform):

                with register_lookup(CharField, transform):

                    authors = Author.objects.filter(

                        **{"name__%s" % transform.lookup_name: trimmed_name}

                    )

                    self.assertQuerysetEqual(authors, [" John  "], lambda a: a.name)