django/tests/postgres_tests/test_trigram.py

58 lines
2.0 KiB
Python

from django.contrib.postgres.search import TrigramDistance, TrigramSimilarity
from django.test import modify_settings
from . import PostgreSQLTestCase
from .models import CharFieldModel, TextFieldModel
@modify_settings(INSTALLED_APPS={'append': 'django.contrib.postgres'})
class TrigramTest(PostgreSQLTestCase):
Model = CharFieldModel
@classmethod
def setUpTestData(cls):
cls.Model.objects.bulk_create([
cls.Model(field='Matthew'),
cls.Model(field='Cat sat on mat.'),
cls.Model(field='Dog sat on rug.'),
])
def test_trigram_search(self):
self.assertQuerysetEqual(
self.Model.objects.filter(field__trigram_similar='Mathew'),
['Matthew'],
transform=lambda instance: instance.field,
)
def test_trigram_similarity(self):
search = 'Bat sat on cat.'
# Round result of similarity because PostgreSQL 12+ uses greater
# precision.
self.assertQuerysetEqual(
self.Model.objects.filter(
field__trigram_similar=search,
).annotate(similarity=TrigramSimilarity('field', search)).order_by('-similarity'),
[('Cat sat on mat.', 0.625), ('Dog sat on rug.', 0.333333)],
transform=lambda instance: (instance.field, round(instance.similarity, 6)),
ordered=True,
)
def test_trigram_similarity_alternate(self):
# Round result of distance because PostgreSQL 12+ uses greater
# precision.
self.assertQuerysetEqual(
self.Model.objects.annotate(
distance=TrigramDistance('field', 'Bat sat on cat.'),
).filter(distance__lte=0.7).order_by('distance'),
[('Cat sat on mat.', 0.375), ('Dog sat on rug.', 0.666667)],
transform=lambda instance: (instance.field, round(instance.distance, 6)),
ordered=True,
)
class TrigramTextFieldTest(TrigramTest):
"""
TextField has the same behavior as CharField regarding trigram lookups.
"""
Model = TextFieldModel