graphene-django/graphene_django/tests/test_fields.py
Steven DeMartini 20a6cecc4c Add test validating query performance with select_related + prefetch_related
This test passes after reverting the `CustomField` resolver change
introduced in
https://github.com/graphql-python/graphene-django/pull/1315, but fails
with that resolver code present. For instance, adding back the resolver
code gives a test failure showing:

```
Failed: Expected to perform 2 queries but 11 were done
```

This should ensure there aren't regressions that prevent
query-optimization in the future.
2023-05-03 11:37:17 +03:00

650 lines
20 KiB
Python

import datetime
import re
from django.db.models import Count, Prefetch
import pytest
from graphene import List, NonNull, ObjectType, Schema, String
from ..fields import DjangoListField
from ..types import DjangoObjectType
from .models import (
Article as ArticleModel,
Film as FilmModel,
FilmDetails as FilmDetailsModel,
Reporter as ReporterModel,
)
class TestDjangoListField:
def test_only_django_object_types(self):
class TestType(ObjectType):
foo = String()
with pytest.raises(AssertionError):
list_field = DjangoListField(TestType)
def test_only_import_paths(self):
list_field = DjangoListField("graphene_django.tests.schema.Human")
from .schema import Human
assert list_field._type.of_type.of_type is Human
def test_non_null_type(self):
class Reporter(DjangoObjectType):
class Meta:
model = ReporterModel
fields = ("first_name",)
list_field = DjangoListField(NonNull(Reporter))
assert isinstance(list_field.type, List)
assert isinstance(list_field.type.of_type, NonNull)
assert list_field.type.of_type.of_type is Reporter
def test_get_django_model(self):
class Reporter(DjangoObjectType):
class Meta:
model = ReporterModel
fields = ("first_name",)
list_field = DjangoListField(Reporter)
assert list_field.model is ReporterModel
def test_list_field_default_queryset(self):
class Reporter(DjangoObjectType):
class Meta:
model = ReporterModel
fields = ("first_name",)
class Query(ObjectType):
reporters = DjangoListField(Reporter)
schema = Schema(query=Query)
query = """
query {
reporters {
firstName
}
}
"""
ReporterModel.objects.create(first_name="Tara", last_name="West")
ReporterModel.objects.create(first_name="Debra", last_name="Payne")
result = schema.execute(query)
assert not result.errors
assert result.data == {
"reporters": [{"firstName": "Tara"}, {"firstName": "Debra"}]
}
def test_list_field_queryset_is_not_cached(self):
class Reporter(DjangoObjectType):
class Meta:
model = ReporterModel
fields = ("first_name",)
class Query(ObjectType):
reporters = DjangoListField(Reporter)
schema = Schema(query=Query)
query = """
query {
reporters {
firstName
}
}
"""
result = schema.execute(query)
assert not result.errors
assert result.data == {"reporters": []}
ReporterModel.objects.create(first_name="Tara", last_name="West")
ReporterModel.objects.create(first_name="Debra", last_name="Payne")
result = schema.execute(query)
assert not result.errors
assert result.data == {
"reporters": [{"firstName": "Tara"}, {"firstName": "Debra"}]
}
def test_override_resolver(self):
class Reporter(DjangoObjectType):
class Meta:
model = ReporterModel
fields = ("first_name",)
class Query(ObjectType):
reporters = DjangoListField(Reporter)
def resolve_reporters(_, info):
return ReporterModel.objects.filter(first_name="Tara")
schema = Schema(query=Query)
query = """
query {
reporters {
firstName
}
}
"""
ReporterModel.objects.create(first_name="Tara", last_name="West")
ReporterModel.objects.create(first_name="Debra", last_name="Payne")
result = schema.execute(query)
assert not result.errors
assert result.data == {"reporters": [{"firstName": "Tara"}]}
def test_nested_list_field(self):
class Article(DjangoObjectType):
class Meta:
model = ArticleModel
fields = ("headline",)
class Reporter(DjangoObjectType):
class Meta:
model = ReporterModel
fields = ("first_name", "articles")
class Query(ObjectType):
reporters = DjangoListField(Reporter)
schema = Schema(query=Query)
query = """
query {
reporters {
firstName
articles {
headline
}
}
}
"""
r1 = ReporterModel.objects.create(first_name="Tara", last_name="West")
ReporterModel.objects.create(first_name="Debra", last_name="Payne")
ArticleModel.objects.create(
headline="Amazing news",
reporter=r1,
pub_date=datetime.date.today(),
pub_date_time=datetime.datetime.now(),
editor=r1,
)
ArticleModel.objects.create(
headline="Not so good news",
reporter=r1,
pub_date=datetime.date.today(),
pub_date_time=datetime.datetime.now(),
editor=r1,
)
result = schema.execute(query)
assert not result.errors
assert result.data == {
"reporters": [
{
"firstName": "Tara",
"articles": [
{"headline": "Amazing news"},
{"headline": "Not so good news"},
],
},
{"firstName": "Debra", "articles": []},
]
}
def test_override_resolver_nested_list_field(self):
class Article(DjangoObjectType):
class Meta:
model = ArticleModel
fields = ("headline",)
class Reporter(DjangoObjectType):
class Meta:
model = ReporterModel
fields = ("first_name", "articles")
def resolve_articles(reporter, info):
return reporter.articles.filter(headline__contains="Amazing")
class Query(ObjectType):
reporters = DjangoListField(Reporter)
schema = Schema(query=Query)
query = """
query {
reporters {
firstName
articles {
headline
}
}
}
"""
r1 = ReporterModel.objects.create(first_name="Tara", last_name="West")
ReporterModel.objects.create(first_name="Debra", last_name="Payne")
ArticleModel.objects.create(
headline="Amazing news",
reporter=r1,
pub_date=datetime.date.today(),
pub_date_time=datetime.datetime.now(),
editor=r1,
)
ArticleModel.objects.create(
headline="Not so good news",
reporter=r1,
pub_date=datetime.date.today(),
pub_date_time=datetime.datetime.now(),
editor=r1,
)
result = schema.execute(query)
assert not result.errors
assert result.data == {
"reporters": [
{"firstName": "Tara", "articles": [{"headline": "Amazing news"}]},
{"firstName": "Debra", "articles": []},
]
}
def test_get_queryset_filter(self):
class Reporter(DjangoObjectType):
class Meta:
model = ReporterModel
fields = ("first_name", "articles")
@classmethod
def get_queryset(cls, queryset, info):
# Only get reporters with at least 1 article
return queryset.annotate(article_count=Count("articles")).filter(
article_count__gt=0
)
class Query(ObjectType):
reporters = DjangoListField(Reporter)
def resolve_reporters(_, info):
return ReporterModel.objects.all()
schema = Schema(query=Query)
query = """
query {
reporters {
firstName
}
}
"""
r1 = ReporterModel.objects.create(first_name="Tara", last_name="West")
ReporterModel.objects.create(first_name="Debra", last_name="Payne")
ArticleModel.objects.create(
headline="Amazing news",
reporter=r1,
pub_date=datetime.date.today(),
pub_date_time=datetime.datetime.now(),
editor=r1,
)
result = schema.execute(query)
assert not result.errors
assert result.data == {"reporters": [{"firstName": "Tara"}]}
def test_resolve_list(self):
"""Resolving a plain list should work (and not call get_queryset)"""
class Reporter(DjangoObjectType):
class Meta:
model = ReporterModel
fields = ("first_name", "articles")
@classmethod
def get_queryset(cls, queryset, info):
# Only get reporters with at least 1 article
return queryset.annotate(article_count=Count("articles")).filter(
article_count__gt=0
)
class Query(ObjectType):
reporters = DjangoListField(Reporter)
def resolve_reporters(_, info):
return [ReporterModel.objects.get(first_name="Debra")]
schema = Schema(query=Query)
query = """
query {
reporters {
firstName
}
}
"""
r1 = ReporterModel.objects.create(first_name="Tara", last_name="West")
ReporterModel.objects.create(first_name="Debra", last_name="Payne")
ArticleModel.objects.create(
headline="Amazing news",
reporter=r1,
pub_date=datetime.date.today(),
pub_date_time=datetime.datetime.now(),
editor=r1,
)
result = schema.execute(query)
assert not result.errors
assert result.data == {"reporters": [{"firstName": "Debra"}]}
def test_get_queryset_foreign_key(self):
class Article(DjangoObjectType):
class Meta:
model = ArticleModel
fields = ("headline",)
@classmethod
def get_queryset(cls, queryset, info):
# Rose tinted glasses
return queryset.exclude(headline__contains="Not so good")
class Reporter(DjangoObjectType):
class Meta:
model = ReporterModel
fields = ("first_name", "articles")
class Query(ObjectType):
reporters = DjangoListField(Reporter)
schema = Schema(query=Query)
query = """
query {
reporters {
firstName
articles {
headline
}
}
}
"""
r1 = ReporterModel.objects.create(first_name="Tara", last_name="West")
ReporterModel.objects.create(first_name="Debra", last_name="Payne")
ArticleModel.objects.create(
headline="Amazing news",
reporter=r1,
pub_date=datetime.date.today(),
pub_date_time=datetime.datetime.now(),
editor=r1,
)
ArticleModel.objects.create(
headline="Not so good news",
reporter=r1,
pub_date=datetime.date.today(),
pub_date_time=datetime.datetime.now(),
editor=r1,
)
result = schema.execute(query)
assert not result.errors
assert result.data == {
"reporters": [
{"firstName": "Tara", "articles": [{"headline": "Amazing news"}]},
{"firstName": "Debra", "articles": []},
]
}
def test_resolve_list_external_resolver(self):
"""Resolving a plain list from external resolver should work (and not call get_queryset)"""
class Reporter(DjangoObjectType):
class Meta:
model = ReporterModel
fields = ("first_name", "articles")
@classmethod
def get_queryset(cls, queryset, info):
# Only get reporters with at least 1 article
return queryset.annotate(article_count=Count("articles")).filter(
article_count__gt=0
)
def resolve_reporters(_, info):
return [ReporterModel.objects.get(first_name="Debra")]
class Query(ObjectType):
reporters = DjangoListField(Reporter, resolver=resolve_reporters)
schema = Schema(query=Query)
query = """
query {
reporters {
firstName
}
}
"""
r1 = ReporterModel.objects.create(first_name="Tara", last_name="West")
ReporterModel.objects.create(first_name="Debra", last_name="Payne")
ArticleModel.objects.create(
headline="Amazing news",
reporter=r1,
pub_date=datetime.date.today(),
pub_date_time=datetime.datetime.now(),
editor=r1,
)
result = schema.execute(query)
assert not result.errors
assert result.data == {"reporters": [{"firstName": "Debra"}]}
def test_get_queryset_filter_external_resolver(self):
class Reporter(DjangoObjectType):
class Meta:
model = ReporterModel
fields = ("first_name", "articles")
@classmethod
def get_queryset(cls, queryset, info):
# Only get reporters with at least 1 article
return queryset.annotate(article_count=Count("articles")).filter(
article_count__gt=0
)
def resolve_reporters(_, info):
return ReporterModel.objects.all()
class Query(ObjectType):
reporters = DjangoListField(Reporter, resolver=resolve_reporters)
schema = Schema(query=Query)
query = """
query {
reporters {
firstName
}
}
"""
r1 = ReporterModel.objects.create(first_name="Tara", last_name="West")
ReporterModel.objects.create(first_name="Debra", last_name="Payne")
ArticleModel.objects.create(
headline="Amazing news",
reporter=r1,
pub_date=datetime.date.today(),
pub_date_time=datetime.datetime.now(),
editor=r1,
)
result = schema.execute(query)
assert not result.errors
assert result.data == {"reporters": [{"firstName": "Tara"}]}
def test_select_related_and_prefetch_related_are_respected(
self, django_assert_num_queries
):
class Article(DjangoObjectType):
class Meta:
model = ArticleModel
fields = ("headline", "editor", "reporter")
class Film(DjangoObjectType):
class Meta:
model = FilmModel
fields = ("genre", "details")
class FilmDetail(DjangoObjectType):
class Meta:
model = FilmDetailsModel
fields = ("location",)
class Reporter(DjangoObjectType):
class Meta:
model = ReporterModel
fields = ("first_name", "articles", "films")
class Query(ObjectType):
articles = DjangoListField(Article)
@staticmethod
def resolve_articles(root, info):
# Optimize for querying associated editors and reporters, and the films and film
# details of those reporters. This is similar to what would happen using a library
# like https://github.com/tfoxy/graphene-django-optimizer for a query like the one
# below (albeit simplified and hardcoded here).
return ArticleModel.objects.select_related(
"editor", "reporter"
).prefetch_related(
Prefetch(
"reporter__films",
queryset=FilmModel.objects.select_related("details"),
),
)
schema = Schema(query=Query)
query = """
query {
articles {
headline
editor {
firstName
}
reporter {
firstName
films {
genre
details {
location
}
}
}
}
}
"""
r1 = ReporterModel.objects.create(first_name="Tara", last_name="West")
r2 = ReporterModel.objects.create(first_name="Debra", last_name="Payne")
ArticleModel.objects.create(
headline="Amazing news",
reporter=r1,
pub_date=datetime.date.today(),
pub_date_time=datetime.datetime.now(),
editor=r2,
)
ArticleModel.objects.create(
headline="Not so good news",
reporter=r2,
pub_date=datetime.date.today(),
pub_date_time=datetime.datetime.now(),
editor=r1,
)
film1 = FilmModel.objects.create(genre="ac")
film2 = FilmModel.objects.create(genre="ot")
film3 = FilmModel.objects.create(genre="do")
FilmDetailsModel.objects.create(location="Hollywood", film=film1)
FilmDetailsModel.objects.create(location="Antarctica", film=film3)
r1.films.add(film1, film2)
r2.films.add(film3)
# We expect 2 queries to be performed based on the above resolver definition: one for all
# articles joined with the reporters model (for associated editors and reporters), and one
# for the films prefetch (which includes its `select_related` JOIN logic in its queryset)
with django_assert_num_queries(2) as captured:
result = schema.execute(query)
assert not result.errors
assert result.data == {
"articles": [
{
"headline": "Amazing news",
"editor": {"firstName": "Debra"},
"reporter": {
"firstName": "Tara",
"films": [
{"genre": "AC", "details": {"location": "Hollywood"}},
{"genre": "OT", "details": None},
],
},
},
{
"headline": "Not so good news",
"editor": {"firstName": "Tara"},
"reporter": {
"firstName": "Debra",
"films": [
{"genre": "DO", "details": {"location": "Antarctica"}},
],
},
},
]
}
assert len(captured.captured_queries) == 2 # Sanity-check
# First we should have queried for all articles in a single query, joining on the reporters
# model (for the editors and reporters ForeignKeys)
assert re.match(
r'SELECT .* "tests_article" INNER JOIN "tests_reporter"',
captured.captured_queries[0]["sql"],
)
# Then we should have queried for all of the films of all reporters, joined with the film
# details for each film, using a single query
assert re.match(
r'SELECT .* FROM "tests_film" INNER JOIN "tests_film_reporters" .* LEFT OUTER JOIN "tests_filmdetails"',
captured.captured_queries[1]["sql"],
)