urban-meal-delivery/tests/db/test_addresses_addresses.py
Alexander Hess cc75307e5a
Add DistanceMatrix class
- the class stores the data of a distance matrix between all addresses
  + air distances
  + bicycle distances
- in addition, the "path" returned by the Google Directions API are
  also stored as a JSON serialized sequence of latitude-longitude pairs
- we assume a symmetric graph
2021-09-12 16:51:10 +02:00

219 lines
7.3 KiB
Python

"""Test the ORM's `DistanceMatrix` model."""
import json
import pytest
import sqlalchemy as sqla
from geopy import distance
from sqlalchemy import exc as sa_exc
from urban_meal_delivery import db
from urban_meal_delivery.db import utils
@pytest.fixture
def another_address(make_address):
"""Another `Address` object in the `city`."""
return make_address()
@pytest.fixture
def assoc(address, another_address, make_address):
"""An association between `address` and `another_address`."""
air_distance = distance.great_circle( # noqa:WPS317
(address.latitude, address.longitude),
(another_address.latitude, another_address.longitude),
).meters
# We put 5 latitude-longitude pairs as the "path" from
# `.first_address` to `.second_address`.
directions = json.dumps(
[
(float(addr.latitude), float(addr.longitude))
for addr in (make_address() for _ in range(5)) # noqa:WPS335
],
)
return db.DistanceMatrix(
first_address=address,
second_address=another_address,
air_distance=round(air_distance),
bicycle_distance=round(1.25 * air_distance),
bicycle_duration=300,
directions=directions,
)
class TestSpecialMethods:
"""Test special methods in `DistanceMatrix`."""
def test_create_an_address_address_association(self, assoc):
"""Test instantiation of a new `DistanceMatrix` object."""
assert assoc is not None
@pytest.mark.db
@pytest.mark.no_cover
class TestConstraints:
"""Test the database constraints defined in `DistanceMatrix`."""
def test_insert_into_database(self, db_session, assoc):
"""Insert an instance into the (empty) database."""
assert db_session.query(db.DistanceMatrix).count() == 0
db_session.add(assoc)
db_session.commit()
assert db_session.query(db.DistanceMatrix).count() == 1
def test_delete_a_referenced_first_address(self, db_session, assoc):
"""Remove a record that is referenced with a FK."""
db_session.add(assoc)
db_session.commit()
# Must delete without ORM as otherwise an UPDATE statement is emitted.
stmt = sqla.delete(db.Address).where(db.Address.id == assoc.first_address.id)
with pytest.raises(
sa_exc.IntegrityError,
match='fk_addresses_addresses_to_addresses_via_first_address', # shortened
):
db_session.execute(stmt)
def test_delete_a_referenced_second_address(self, db_session, assoc):
"""Remove a record that is referenced with a FK."""
db_session.add(assoc)
db_session.commit()
# Must delete without ORM as otherwise an UPDATE statement is emitted.
stmt = sqla.delete(db.Address).where(db.Address.id == assoc.second_address.id)
with pytest.raises(
sa_exc.IntegrityError,
match='fk_addresses_addresses_to_addresses_via_second_address', # shortened
):
db_session.execute(stmt)
def test_reference_an_invalid_city(self, db_session, address, another_address):
"""Insert a record with an invalid foreign key."""
db_session.add(address)
db_session.add(another_address)
db_session.commit()
# Must insert without ORM as otherwise SQLAlchemy figures out
# that something is wrong before any query is sent to the database.
stmt = sqla.insert(db.DistanceMatrix).values(
first_address_id=address.id,
second_address_id=another_address.id,
city_id=999,
air_distance=123,
)
with pytest.raises(
sa_exc.IntegrityError,
match='fk_addresses_addresses_to_addresses_via_first_address', # shortened
):
db_session.execute(stmt)
def test_redundant_addresses(self, db_session, assoc):
"""Insert a record that violates a unique constraint."""
db_session.add(assoc)
db_session.commit()
# Must insert without ORM as otherwise SQLAlchemy figures out
# that something is wrong before any query is sent to the database.
stmt = sqla.insert(db.DistanceMatrix).values(
first_address_id=assoc.first_address.id,
second_address_id=assoc.second_address.id,
city_id=assoc.city_id,
air_distance=assoc.air_distance,
)
with pytest.raises(sa_exc.IntegrityError, match='duplicate key value'):
db_session.execute(stmt)
def test_symmetric_addresses(self, db_session, assoc):
"""Insert a record that violates a check constraint."""
db_session.add(assoc)
db_session.commit()
another_assoc = db.DistanceMatrix(
first_address=assoc.second_address,
second_address=assoc.first_address,
air_distance=assoc.air_distance,
)
db_session.add(another_assoc)
with pytest.raises(
sa_exc.IntegrityError,
match='ck_addresses_addresses_on_distances_are_symmetric_for_bicycles',
):
db_session.commit()
def test_negative_air_distance(self, db_session, assoc):
"""Insert an instance with invalid data."""
assoc.air_distance = -1
db_session.add(assoc)
with pytest.raises(sa_exc.IntegrityError, match='realistic_air_distance'):
db_session.commit()
def test_air_distance_too_large(self, db_session, assoc):
"""Insert an instance with invalid data."""
assoc.air_distance = 20_000
assoc.bicycle_distance = 21_000
db_session.add(assoc)
with pytest.raises(sa_exc.IntegrityError, match='realistic_air_distance'):
db_session.commit()
def test_bicycle_distance_too_large(self, db_session, assoc):
"""Insert an instance with invalid data."""
assoc.bicycle_distance = 25_000
db_session.add(assoc)
with pytest.raises(sa_exc.IntegrityError, match='realistic_bicycle_distance'):
db_session.commit()
def test_air_distance_shorter_than_bicycle_distance(self, db_session, assoc):
"""Insert an instance with invalid data."""
assoc.bicycle_distance = round(0.75 * assoc.air_distance)
db_session.add(assoc)
with pytest.raises(sa_exc.IntegrityError, match='air_distance_is_shortest'):
db_session.commit()
@pytest.mark.parametrize('duration', [-1, 3601])
def test_unrealistic_bicycle_travel_time(self, db_session, assoc, duration):
"""Insert an instance with invalid data."""
assoc.bicycle_duration = duration
db_session.add(assoc)
with pytest.raises(
sa_exc.IntegrityError, match='realistic_bicycle_travel_time',
):
db_session.commit()
class TestProperties:
"""Test properties in `DistanceMatrix`."""
def test_path_structure(self, assoc):
"""Test `DistanceMatrix.path` property."""
result = assoc.path
assert isinstance(result, list)
assert isinstance(result[0], utils.Location)
def test_path_content(self, assoc):
"""Test `DistanceMatrix.path` property."""
result = assoc.path
assert len(result) == 5 # = 5 inner points, excluding start and end
def test_path_is_cached(self, assoc):
"""Test `DistanceMatrix.path` property."""
result1 = assoc.path
result2 = assoc.path
assert result1 is result2