3 files changed, 302 insertions, 0 deletions
diff --git a/tests/postgres_tests/migrations/0002_create_test_models.py b/tests/postgres_tests/migrations/0002_create_test_models.py
index c4f031f6d0..7853f40a14 100644
--- a/tests/postgres_tests/migrations/0002_create_test_models.py
+++ b/tests/postgres_tests/migrations/0002_create_test_models.py
@@ -105,6 +105,24 @@ class Migration(migrations.Migration):
             options=None,
             bases=None,
         ),
+        migrations.CreateModel(
+            name='AggregateTestModel',
+            fields=[
+                ('id', models.AutoField(verbose_name='ID', serialize=False, auto_created=True, primary_key=True)),
+                ('boolean_field', models.NullBooleanField()),
+                ('char_field', models.CharField(max_length=30, blank=True)),
+                ('integer_field', models.IntegerField(null=True)),
+            ]
+        ),
+        migrations.CreateModel(
+            name='StatTestModel',
+            fields=[
+                ('id', models.AutoField(verbose_name='ID', serialize=False, auto_created=True, primary_key=True)),
+                ('int1', models.IntegerField()),
+                ('int2', models.IntegerField()),
+                ('related_field', models.ForeignKey('postgres_tests.AggregateTestModel', null=True)),
+            ]
+        ),
     ]
 
     pg_92_operations = [
diff --git a/tests/postgres_tests/models.py b/tests/postgres_tests/models.py
index f698d56a58..b53eda4cca 100644
--- a/tests/postgres_tests/models.py
+++ b/tests/postgres_tests/models.py
@@ -62,3 +62,21 @@ else:
 class ArrayFieldSubclass(ArrayField):
     def __init__(self, *args, **kwargs):
         super(ArrayFieldSubclass, self).__init__(models.IntegerField())
+
+
+class AggregateTestModel(models.Model):
+    """
+    To test postgres-specific general aggregation functions
+    """
+    char_field = models.CharField(max_length=30, blank=True)
+    integer_field = models.IntegerField(null=True)
+    boolean_field = models.NullBooleanField()
+
+
+class StatTestModel(models.Model):
+    """
+    To test postgres-specific aggregation functions for statistics
+    """
+    int1 = models.IntegerField()
+    int2 = models.IntegerField()
+    related_field = models.ForeignKey(AggregateTestModel, null=True)
diff --git a/tests/postgres_tests/test_aggregates.py b/tests/postgres_tests/test_aggregates.py
new file mode 100644
index 0000000000..2857d917d5
--- /dev/null
+++ b/tests/postgres_tests/test_aggregates.py
@@ -0,0 +1,266 @@
+from django.contrib.postgres.aggregates import (
+    ArrayAgg, BitAnd, BitOr, BoolAnd, BoolOr, Corr, CovarPop, RegrAvgX,
+    RegrAvgY, RegrCount, RegrIntercept, RegrR2, RegrSlope, RegrSXX, RegrSXY,
+    RegrSYY, StatAggregate, StringAgg,
+)
+from django.db.models.expressions import F, Value
+from django.test import TestCase
+from django.test.utils import Approximate
+
+from .models import AggregateTestModel, StatTestModel
+
+
+class TestGeneralAggregate(TestCase):
+    @classmethod
+    def setUpTestData(cls):
+        AggregateTestModel.objects.create(boolean_field=True, char_field='Foo1', integer_field=0)
+        AggregateTestModel.objects.create(boolean_field=False, char_field='Foo2', integer_field=1)
+        AggregateTestModel.objects.create(boolean_field=False, char_field='Foo3', integer_field=2)
+        AggregateTestModel.objects.create(boolean_field=True, char_field='Foo4', integer_field=0)
+
+    def test_array_agg_charfield(self):
+        values = AggregateTestModel.objects.aggregate(arrayagg=ArrayAgg('char_field'))
+        self.assertEqual(values, {'arrayagg': ['Foo1', 'Foo2', 'Foo3', 'Foo4']})
+
+    def test_array_agg_integerfield(self):
+        values = AggregateTestModel.objects.aggregate(arrayagg=ArrayAgg('integer_field'))
+        self.assertEqual(values, {'arrayagg': [0, 1, 2, 0]})
+
+    def test_array_agg_booleanfield(self):
+        values = AggregateTestModel.objects.aggregate(arrayagg=ArrayAgg('boolean_field'))
+        self.assertEqual(values, {'arrayagg': [True, False, False, True]})
+
+    def test_array_agg_empty_result(self):
+        AggregateTestModel.objects.all().delete()
+        values = AggregateTestModel.objects.aggregate(arrayagg=ArrayAgg('char_field'))
+        self.assertEqual(values, {'arrayagg': []})
+        values = AggregateTestModel.objects.aggregate(arrayagg=ArrayAgg('integer_field'))
+        self.assertEqual(values, {'arrayagg': []})
+        values = AggregateTestModel.objects.aggregate(arrayagg=ArrayAgg('boolean_field'))
+        self.assertEqual(values, {'arrayagg': []})
+
+    def test_bit_and_general(self):
+        values = AggregateTestModel.objects.filter(
+            integer_field__in=[0, 1]).aggregate(bitand=BitAnd('integer_field'))
+        self.assertEqual(values, {'bitand': 0})
+
+    def test_bit_and_on_only_true_values(self):
+        values = AggregateTestModel.objects.filter(
+            integer_field=1).aggregate(bitand=BitAnd('integer_field'))
+        self.assertEqual(values, {'bitand': 1})
+
+    def test_bit_and_on_only_false_values(self):
+        values = AggregateTestModel.objects.filter(
+            integer_field=0).aggregate(bitand=BitAnd('integer_field'))
+        self.assertEqual(values, {'bitand': 0})
+
+    def test_bit_and_empty_result(self):
+        AggregateTestModel.objects.all().delete()
+        values = AggregateTestModel.objects.aggregate(bitand=BitAnd('integer_field'))
+        self.assertEqual(values, {'bitand': None})
+
+    def test_bit_or_general(self):
+        values = AggregateTestModel.objects.filter(
+            integer_field__in=[0, 1]).aggregate(bitor=BitOr('integer_field'))
+        self.assertEqual(values, {'bitor': 1})
+
+    def test_bit_or_on_only_true_values(self):
+        values = AggregateTestModel.objects.filter(
+            integer_field=1).aggregate(bitor=BitOr('integer_field'))
+        self.assertEqual(values, {'bitor': 1})
+
+    def test_bit_or_on_only_false_values(self):
+        values = AggregateTestModel.objects.filter(
+            integer_field=0).aggregate(bitor=BitOr('integer_field'))
+        self.assertEqual(values, {'bitor': 0})
+
+    def test_bit_or_empty_result(self):
+        AggregateTestModel.objects.all().delete()
+        values = AggregateTestModel.objects.aggregate(bitor=BitOr('integer_field'))
+        self.assertEqual(values, {'bitor': None})
+
+    def test_bool_and_general(self):
+        values = AggregateTestModel.objects.aggregate(booland=BoolAnd('boolean_field'))
+        self.assertEqual(values, {'booland': False})
+
+    def test_bool_and_empty_result(self):
+        AggregateTestModel.objects.all().delete()
+        values = AggregateTestModel.objects.aggregate(booland=BoolAnd('boolean_field'))
+        self.assertEqual(values, {'booland': None})
+
+    def test_bool_or_general(self):
+        values = AggregateTestModel.objects.aggregate(boolor=BoolOr('boolean_field'))
+        self.assertEqual(values, {'boolor': True})
+
+    def test_bool_or_empty_result(self):
+        AggregateTestModel.objects.all().delete()
+        values = AggregateTestModel.objects.aggregate(boolor=BoolOr('boolean_field'))
+        self.assertEqual(values, {'boolor': None})
+
+    def test_string_agg_requires_delimiter(self):
+        with self.assertRaises(TypeError):
+            AggregateTestModel.objects.aggregate(stringagg=StringAgg('char_field'))
+
+    def test_string_agg_charfield(self):
+        values = AggregateTestModel.objects.aggregate(stringagg=StringAgg('char_field', delimiter=';'))
+        self.assertEqual(values, {'stringagg': 'Foo1;Foo2;Foo3;Foo4'})
+
+    def test_string_agg_empty_result(self):
+        AggregateTestModel.objects.all().delete()
+        values = AggregateTestModel.objects.aggregate(stringagg=StringAgg('char_field', delimiter=';'))
+        self.assertEqual(values, {'stringagg': ''})
+
+
+class TestStatisticsAggregate(TestCase):
+    @classmethod
+    def setUpTestData(cls):
+        StatTestModel.objects.create(
+            int1=1,
+            int2=3,
+            related_field=AggregateTestModel.objects.create(integer_field=0),
+        )
+        StatTestModel.objects.create(
+            int1=2,
+            int2=2,
+            related_field=AggregateTestModel.objects.create(integer_field=1),
+        )
+        StatTestModel.objects.create(
+            int1=3,
+            int2=1,
+            related_field=AggregateTestModel.objects.create(integer_field=2),
+        )
+
+    # Tests for base class (StatAggregate)
+
+    def test_missing_arguments_raises_exception(self):
+        with self.assertRaisesMessage(ValueError, 'Both y and x must be provided.'):
+            StatAggregate(x=None, y=None)
+
+    def test_correct_source_expressions(self):
+        func = StatAggregate(x='test', y=13)
+        self.assertIsInstance(func.source_expressions[0], Value)
+        self.assertIsInstance(func.source_expressions[1], F)
+
+    def test_alias_is_required(self):
+        class SomeFunc(StatAggregate):
+            function = 'TEST'
+        with self.assertRaisesMessage(TypeError, 'Complex aggregates require an alias'):
+            StatTestModel.objects.aggregate(SomeFunc(y='int2', x='int1'))
+
+    # Test aggregates
+
+    def test_corr_general(self):
+        values = StatTestModel.objects.aggregate(corr=Corr(y='int2', x='int1'))
+        self.assertEqual(values, {'corr': -1.0})
+
+    def test_corr_empty_result(self):
+        StatTestModel.objects.all().delete()
+        values = StatTestModel.objects.aggregate(corr=Corr(y='int2', x='int1'))
+        self.assertEqual(values, {'corr': None})
+
+    def test_covar_pop_general(self):
+        values = StatTestModel.objects.aggregate(covarpop=CovarPop(y='int2', x='int1'))
+        self.assertEqual(values, {'covarpop': Approximate(-0.66, places=1)})
+
+    def test_covar_pop_empty_result(self):
+        StatTestModel.objects.all().delete()
+        values = StatTestModel.objects.aggregate(covarpop=CovarPop(y='int2', x='int1'))
+        self.assertEqual(values, {'covarpop': None})
+
+    def test_covar_pop_sample(self):
+        values = StatTestModel.objects.aggregate(covarpop=CovarPop(y='int2', x='int1', sample=True))
+        self.assertEqual(values, {'covarpop': -1.0})
+
+    def test_covar_pop_sample_empty_result(self):
+        StatTestModel.objects.all().delete()
+        values = StatTestModel.objects.aggregate(covarpop=CovarPop(y='int2', x='int1', sample=True))
+        self.assertEqual(values, {'covarpop': None})
+
+    def test_regr_avgx_general(self):
+        values = StatTestModel.objects.aggregate(regravgx=RegrAvgX(y='int2', x='int1'))
+        self.assertEqual(values, {'regravgx': 2.0})
+
+    def test_regr_avgx_empty_result(self):
+        StatTestModel.objects.all().delete()
+        values = StatTestModel.objects.aggregate(regravgx=RegrAvgX(y='int2', x='int1'))
+        self.assertEqual(values, {'regravgx': None})
+
+    def test_regr_avgy_general(self):
+        values = StatTestModel.objects.aggregate(regravgy=RegrAvgY(y='int2', x='int1'))
+        self.assertEqual(values, {'regravgy': 2.0})
+
+    def test_regr_avgy_empty_result(self):
+        StatTestModel.objects.all().delete()
+        values = StatTestModel.objects.aggregate(regravgy=RegrAvgY(y='int2', x='int1'))
+        self.assertEqual(values, {'regravgy': None})
+
+    def test_regr_count_general(self):
+        values = StatTestModel.objects.aggregate(regrcount=RegrCount(y='int2', x='int1'))
+        self.assertEqual(values, {'regrcount': 3})
+
+    def test_regr_count_empty_result(self):
+        StatTestModel.objects.all().delete()
+        values = StatTestModel.objects.aggregate(regrcount=RegrCount(y='int2', x='int1'))
+        self.assertEqual(values, {'regrcount': 0})
+
+    def test_regr_intercept_general(self):
+        values = StatTestModel.objects.aggregate(regrintercept=RegrIntercept(y='int2', x='int1'))
+        self.assertEqual(values, {'regrintercept': 4})
+
+    def test_regr_intercept_empty_result(self):
+        StatTestModel.objects.all().delete()
+        values = StatTestModel.objects.aggregate(regrintercept=RegrIntercept(y='int2', x='int1'))
+        self.assertEqual(values, {'regrintercept': None})
+
+    def test_regr_r2_general(self):
+        values = StatTestModel.objects.aggregate(regrr2=RegrR2(y='int2', x='int1'))
+        self.assertEqual(values, {'regrr2': 1})
+
+    def test_regr_r2_empty_result(self):
+        StatTestModel.objects.all().delete()
+        values = StatTestModel.objects.aggregate(regrr2=RegrR2(y='int2', x='int1'))
+        self.assertEqual(values, {'regrr2': None})
+
+    def test_regr_slope_general(self):
+        values = StatTestModel.objects.aggregate(regrslope=RegrSlope(y='int2', x='int1'))
+        self.assertEqual(values, {'regrslope': -1})
+
+    def test_regr_slope_empty_result(self):
+        StatTestModel.objects.all().delete()
+        values = StatTestModel.objects.aggregate(regrslope=RegrSlope(y='int2', x='int1'))
+        self.assertEqual(values, {'regrslope': None})
+
+    def test_regr_sxx_general(self):
+        values = StatTestModel.objects.aggregate(regrsxx=RegrSXX(y='int2', x='int1'))
+        self.assertEqual(values, {'regrsxx': 2.0})
+
+    def test_regr_sxx_empty_result(self):
+        StatTestModel.objects.all().delete()
+        values = StatTestModel.objects.aggregate(regrsxx=RegrSXX(y='int2', x='int1'))
+        self.assertEqual(values, {'regrsxx': None})
+
+    def test_regr_sxy_general(self):
+        values = StatTestModel.objects.aggregate(regrsxy=RegrSXY(y='int2', x='int1'))
+        self.assertEqual(values, {'regrsxy': -2.0})
+
+    def test_regr_sxy_empty_result(self):
+        StatTestModel.objects.all().delete()
+        values = StatTestModel.objects.aggregate(regrsxy=RegrSXY(y='int2', x='int1'))
+        self.assertEqual(values, {'regrsxy': None})
+
+    def test_regr_syy_general(self):
+        values = StatTestModel.objects.aggregate(regrsyy=RegrSYY(y='int2', x='int1'))
+        self.assertEqual(values, {'regrsyy': 2.0})
+
+    def test_regr_syy_empty_result(self):
+        StatTestModel.objects.all().delete()
+        values = StatTestModel.objects.aggregate(regrsyy=RegrSYY(y='int2', x='int1'))
+        self.assertEqual(values, {'regrsyy': None})
+
+    def test_regr_avgx_with_related_obj_and_number_as_argument(self):
+        """
+        This is more complex test to check if JOIN on field and
+        number as argument works as expected.
+        """
+        values = StatTestModel.objects.aggregate(complex_regravgx=RegrAvgX(y=5, x='related_field__integer_field'))
+        self.assertEqual(values, {'complex_regravgx': 1.0})