FastAPI + SQLAlchemy + PyTest coverage

site/content/posts/fastapi-sqlalchemy-pytest-coverage.md

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+---
+title: "FastAPI + SQLAlchemy PyTest coverage"
+date: "2024-03-20"
+---
+
+If you try to run [pytest-cov](https://pypi.org/project/pytest-cov/) with FastAPI and SQLAlchemy, you'll get a bunch of uncovered lines since the default configuration won't work.
+
+An example line that wouldn't be covered in this senario would be `items.scalars().first()`. First, add the [gevent](https://pypi.org/project/gevent/) package to your environment, and then add the following lines to your `pyproject.toml`:
+
+```toml
+[tool.coverage.run]
+concurrency = ["gevent"]
+```
+
+If you don't have a script for running tests in `pyproject.toml`, you can use something like
+
+```toml
+test-cov = "python3 -m pytest --cov=./ --cov-report=xml"
+```
+
+Original issue: https://github.com/nedbat/coveragepy/issues/1012