News FastAPI

Architecture

This project uses Hexagonal Architecture and DDD.

Packages

news_fastapi.domain

DDD related code.

news_fastapi.domain.seed_work

Micro-framework for other domain related code. See ".NET Microservices: Architecture for Containerized .NET Applications" section "Seedwork (reusable base classes and interfaces for your domain model)" https://learn.microsoft.com/en-us/dotnet/architecture/microservices/microservice-ddd-cqrs-patterns/seedwork-domain-model-base-classes-interfaces

news_fastapi.domain.*

Aggregates are named by their root entity name without any special suffixes.

*Factory classes are factories for aggregates. They are concrete classes but can be inherited and overriden on infrastructure level.

*Repository abstract classes declares repository interface. They are implemented on infrastructure level.

DomainEvent-based classes are DTO for domain events.

*Service classes are responsible for execution of domain-level operations. Also, domain level services can be defined in any way that fits better for concrete operation.

news_fastapi.domain.value_objects

Reusable value-objects as they are defined in DDD.

news_fastapi.core

Application core as it is in Hexagonal Architecture.

news_fastapi.core.*.command

*Service classes are responsible for execution of commands.

news_fastapi.core.*.queries

*Queries abstract classes are responsible for declaration of queries. These classes are implemented in adapters layer.

*Service classes are responsible for execution of queries.

news_fastapi.core.*.auth

*Auth abstract classes are responsible for declaration of authorization methods and methods returning information about current user.

news_fastapi.core.*.exceptions and news_fastapi.core.exceptions

Application core level exceptions. Usually raised by command or query services.

news_fastapi.core.events

Defines event handlers for domain events.

news_fastapi.core.transaction

Defines abstract transaction manager interface. This interface is implemented at infrastructure level.

news_fastapi.adapters

Various adapters as defined in Hexagonal Architecture.

news_fastapi.adapters.auth

Implements authentication and authorization.

news_fastapi.adapters.persistence

All persistence related implementations, i.e. implements repositories, queries, etc.

news_fastapi.adapters.persistence.tortoise

Persistence related code implemented with TortoiseORM.

news_fastapi.adapters.persistence.sqlalchemy

Persistence implemented with SQLAlchemy, partially with Core and partially with Imperative Mapping.

This implementation maps database rows directly to entity classes.

Probably, this way is more preferable when used with hexagonal architecture, because it allows to completely separate entities and persistence and doesn't introduce any intermediate models. But it also has its own downsides: since it monkey patches entity classes, it can probably break them and also heavily depends on implementation details, i.e. protected attributes of entity classes.

news_fastapi.adapters.persistence.sqlalchemy_core

Persistence implemented with SQLAlchemy Core only. No ORM used.

news_fastapi.adapeters.persistence.sqlalchemy_orm_naive

Persistence implemented with SQLAlchemy ORM.

'Naive' here means that ORM maps database rows not to entity classes, but to intermediate model classes. Then the model classes are manually mapped to entity classes in repositories.

For direct mapping DB rows to entities see news_fastapi.adapters.persistence.sqlalchemy.

news_fastapi.adapters.rest_api

REST API related code: controllers, middleware, ASGI app, etc.

news_fastapi.main

news_fastapi.main.asgi constructs ASGI application for ASGI web servers, such as uvicorn.

news_fastapi.main.container IOC container, dependency root.

news_fastapi.main.* another application entrypoints, usually auxiliary CLI scripts.

QA

Code quality

Run the following commands to check the code quality:

cd src

# sort imports
isort .

# format code
black .

# check types
mypy news_fastapi

# lint
pylint --rcfile ../pyproject.toml news_fastapi

# all previous commands can be run at once by qa.sh script
./qa.sh

Tests

cd src

# all tests
python -m unittest

# tests from single file
python -m unittest tests/path/to/file/test_whatever_you_need.py

# tests from package
python -m unittest discover tests/path/to/package/directory/