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)