from django.db.models import F, Value from django.db.models.functions import Concat, Replace from django.test import TestCase from ..models import Author class ReplaceTests(TestCase): @classmethod def setUpTestData(cls): Author.objects.create(name="George R. R. Martin") Author.objects.create(name="J. R. R. Tolkien") def test_replace_with_empty_string(self): qs = Author.objects.annotate( without_middlename=Replace(F("name"), Value("R. R. "), Value("")), ) self.assertQuerySetEqual( qs, [ ("George R. R. Martin", "George Martin"), ("J. R. R. Tolkien", "J. Tolkien"), ], transform=lambda x: (x.name, x.without_middlename), ordered=False, ) def test_case_sensitive(self): qs = Author.objects.annotate( same_name=Replace(F("name"), Value("r. r."), Value("")) ) self.assertQuerySetEqual( qs, [ ("George R. R. Martin", "George R. R. Martin"), ("J. R. R. Tolkien", "J. R. R. Tolkien"), ], transform=lambda x: (x.name, x.same_name), ordered=False, ) def test_replace_expression(self): qs = Author.objects.annotate( same_name=Replace( Concat(Value("Author: "), F("name")), Value("Author: "), Value("") ), ) self.assertQuerySetEqual( qs, [ ("George R. R. Martin", "George R. R. Martin"), ("J. R. R. Tolkien", "J. R. R. Tolkien"), ], transform=lambda x: (x.name, x.same_name), ordered=False, ) def test_update(self): Author.objects.update( name=Replace(F("name"), Value("R. R. "), Value("")), ) self.assertQuerySetEqual( Author.objects.all(), [ ("George Martin"), ("J. Tolkien"), ], transform=lambda x: x.name, ordered=False, ) def test_replace_with_default_arg(self): # The default replacement is an empty string. qs = Author.objects.annotate(same_name=Replace(F("name"), Value("R. R. "))) self.assertQuerySetEqual( qs, [ ("George R. R. Martin", "George Martin"), ("J. R. R. Tolkien", "J. Tolkien"), ], transform=lambda x: (x.name, x.same_name), ordered=False, )