1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
|
import pytest
import sqlalchemy as sa
from sqlalchemy_utils.observer import observes
@pytest.fixture
def Catalog(Base):
catalog_category = sa.Table(
'catalog_category',
Base.metadata,
sa.Column('catalog_id', sa.Integer, sa.ForeignKey('catalog.id')),
sa.Column('category_id', sa.Integer, sa.ForeignKey('category.id'))
)
class Catalog(Base):
__tablename__ = 'catalog'
id = sa.Column(sa.Integer, primary_key=True)
product_count = sa.Column(sa.Integer, default=0)
@observes('categories.sub_categories.products')
def product_observer(self, products):
self.product_count = len(products)
categories = sa.orm.relationship(
'Category',
backref='catalogs',
secondary=catalog_category
)
return Catalog
@pytest.fixture
def Category(Base):
category_subcategory = sa.Table(
'category_subcategory',
Base.metadata,
sa.Column(
'category_id',
sa.Integer,
sa.ForeignKey('category.id')
),
sa.Column(
'subcategory_id',
sa.Integer,
sa.ForeignKey('sub_category.id')
)
)
class Category(Base):
__tablename__ = 'category'
id = sa.Column(sa.Integer, primary_key=True)
sub_categories = sa.orm.relationship(
'SubCategory',
backref='categories',
secondary=category_subcategory
)
return Category
@pytest.fixture
def SubCategory(Base):
subcategory_product = sa.Table(
'subcategory_product',
Base.metadata,
sa.Column(
'subcategory_id',
sa.Integer,
sa.ForeignKey('sub_category.id')
),
sa.Column(
'product_id',
sa.Integer,
sa.ForeignKey('product.id')
)
)
class SubCategory(Base):
__tablename__ = 'sub_category'
id = sa.Column(sa.Integer, primary_key=True)
products = sa.orm.relationship(
'Product',
backref='sub_categories',
secondary=subcategory_product
)
return SubCategory
@pytest.fixture
def Product(Base):
class Product(Base):
__tablename__ = 'product'
id = sa.Column(sa.Integer, primary_key=True)
price = sa.Column(sa.Numeric)
return Product
@pytest.fixture
def init_models(Catalog, Category, SubCategory, Product):
pass
@pytest.fixture
def catalog(session, Catalog, Category, SubCategory, Product):
sub_category = SubCategory(products=[Product()])
category = Category(sub_categories=[sub_category])
catalog = Catalog(categories=[category])
session.add(catalog)
session.flush()
return catalog
@pytest.mark.usefixtures('postgresql_dsn')
class TestObservesForManyToManyToManyToMany:
def test_simple_insert(self, catalog):
assert catalog.product_count == 1
def test_add_leaf_object(self, catalog, session, Product):
product = Product()
catalog.categories[0].sub_categories[0].products.append(product)
session.flush()
assert catalog.product_count == 2
def test_remove_leaf_object(self, catalog, session, Product):
product = Product()
catalog.categories[0].sub_categories[0].products.append(product)
session.flush()
session.delete(product)
session.flush()
assert catalog.product_count == 1
def test_delete_intermediate_object(self, catalog, session):
session.delete(catalog.categories[0].sub_categories[0])
session.commit()
assert catalog.product_count == 0
def test_gathered_objects_are_distinct(
self,
session,
Catalog,
Category,
SubCategory,
Product
):
catalog = Catalog()
category = Category(catalogs=[catalog])
product = Product()
category.sub_categories.append(
SubCategory(products=[product])
)
session.add(
SubCategory(categories=[category], products=[product])
)
session.commit()
assert catalog.product_count == 1
|
