如何使用pytest，fastapi和tortoise-orm对每个测试进行回滚？

Question

我正在为crud编写单元测试，我使用的框架是FastAPI，ORM是乌龟，测试模块是pytest。

我有一个配置文件：

import os

import pytest
from starlette.testclient import TestClient
from tortoise.contrib.fastapi import register_tortoise

from app.config import Settings, get_settings
from app.main import create_application


def get_settings_override():
    return Settings(
        testing=1, database_url=os.environ.get("DATABASE_TEST_URL")
    )

@pytest.fixture(scope="module")
def test_app_with_db():
    # set up
    app = create_application()
    app.dependency_overrides[get_settings] = get_settings_override

    # Link with DB for testing
    register_tortoise(
        app,
        db_url=os.environ.get("DATABASE_TEST_URL"),
        modules={"models": ["app.infra.postgres.models"]},
        generate_schemas=True,
        add_exception_handlers=True,
    )
    with TestClient(app) as test_client:

        # testing
        yield test_client

    # tear down

此外，我有这些测试，第一次创造了一个新的载体。第二个，创建一个载体，然后搜索数据库中的所有现有载波。

import json
from app.infra.postgres.crud.cft import cft as pg_cft
from app.services.cft import CFTService

cft_crud = CFTService(pg_cft)

PREFIX = "/api/cft/"


def test_create_carrier(test_app_with_db):
    response = test_app_with_db.post(
        f"{PREFIX}",
        data=json.dumps(
            {
                "broker_id": 1,
                "carrier_id": 1,
                "lower_limit": 10,
                "upper_limit": 100,
                "fee": 50,
                "is_active": True,
            }
        ),
    )
    assert response.status_code == 201
    assert type(response.json()["id"]) == int


def test_get_carriers(test_app_with_db):
    response = test_app_with_db.post(
        f"{PREFIX}",
        data=json.dumps(
            {
                "broker_id": 1,
                "carrier_id": 1,
                "lower_limit": 10,
                "upper_limit": 100,
                "fee": 50,
                "is_active": True,
            }
        ),
    )
    summary_id = response.json()["id"]

    response = test_app_with_db.get(f"{PREFIX}")
    assert response.status_code == 200

    response_list = response.json()

    assert (
        len(list(filter(lambda d: d["id"] == summary_id, response_list))) == 1
    )

问题是，当我使用命令docker-compose -f Docker-compose.dev.yml exec web python -m pytest (是、web、、容器的名称)运行测试时，我会得到一个错误，因为已经有了broker_id和carrier_id的组合。我想要的是为每个测试还原数据库。我怎么能这么做？

编辑：

我就是这样做我想做的

import os

import pytest
from starlette.testclient import TestClient
from tortoise.contrib.test import finalizer, initializer

from app.config import Settings, get_settings
from app.main import create_application


def get_settings_override():
    return Settings(testing=1, database_dev_url=os.environ.get("DATABASE_TEST_URL"))


@pytest.fixture(scope="function")
def test_app():
    # set up
    app = create_application()
    app.dependency_overrides[get_settings] = get_settings_override

    with TestClient(app) as test_client:

        # testing
        yield test_client

    # tear down


@pytest.fixture(scope="function")
def test_app_with_db():
    # set up
    app = create_application()
    app.dependency_overrides[get_settings] = get_settings_override

    # Link with DB for testing
    initializer(
        ["app.infra.postgres.models"],
        db_url=os.environ.get("DATABASE_TEST_URL"),
    )

    with TestClient(app) as test_client:
        # testing
        yield test_client

    # tear down
    finalizer()

Answer 1

正如MrBean所说，您需要让夹具运行于每个测试，而不是每个模块。

您可以这样更改范围：

@pytest.fixture(scope="function")
def test_app_with_db():
    # set up
...

或者可以完全删除scope参数，因为它默认为function。

https://docs.pytest.org/en/stable/fixture.html#scope-sharing-fixtures-across-classes-modules-packages-or-session

这是假设您实际上在夹具的# teardown部分中有一些内容。否则就没有什么可以清理数据库了。