Adapt code to prevent new warnings and errors (as of SQLAlchemy 1.4):
- Overlapping foreign key columns could be set in a conflicting way
=> This is prevented by the application logic
=> Ignore the warning by setting a `overlaps` flag
- Transaction already rolled back
=> This only happens when tests cause an `IntegrityError` on purpose
=> Filter away the corresponding warning in the fixture
- Query returns `Row` objects and not scalars
=> Add genexpr to pull out `primary_id`
... from the dev dependencies.
Longer queries in SQLAlchemy get flagged even though they are not
complicated. Other expressions are generally not that complicated.
- ensure a `Restaurant` only has one unique `Order.pickup_address`
- rework `Grid.gridify()` so that only pickup addresses are assigned
into `Pixel`s
- include database migrations to ensure the data adhere to these
tighter constraints
- create `*Factory` classes with fakerboy and faker that generate
randomized instances of the ORM models
- add new pytest marker: "db" are the integration tests involving the
database whereas "e2e" will be all other integration tests
- streamline the docstrings in the ORM models
- use SQLAlchemy (and PostgreSQL) to model the ORM layer
- add the following models:
+ Address => modelling all kinds of addresses
+ City => model the three target cities
+ Courier => model the UDP's couriers
+ Customer => model the UDP's customers
+ Order => model the orders received by the UDP
+ Restaurant => model the restaurants active on the UDP
- so far, the emphasis lies on expression the Foreign Key
and Check Constraints that are used to validate the assumptions
inherent to the cleanded data
- provide database-independent unit tests with 100% coverage
- provide additional integration tests ("e2e") that commit data to
a PostgreSQL instance to validate that the constraints work
- adapt linting rules a bit
