pytest-airflow-in-a-box

pytest-airflow-in-a-box is a pytest plugin for testing Apache Airflow DAGs without a live Airflow deployment. It targets Airflow 3 and provides the package and plugin foundation for a small, typed testing surface.

The package auto-registers with pytest, creates an isolated metadata database, and provides typed fixtures for persisted Dags, DagRuns, task instances, sessions, and Dag bags.

Contents

• Quickstart
• Why not...
• Requirements
• Installation
• GitHub Action
• Migration diff orchestrator
• Documentation
• Development
• License
• Manifesto

Quickstart

uv add --dev "pytest-airflow-in-a-box[airflow3]"
pip install "pytest-airflow-in-a-box[airflow3]"

from airflow.sdk import task


def test_dag(dag_maker):
    with dag_maker():

        @task
        def produce():
            return 21

        @task
        def consume(value):
            return value * 2

        consume(produce())

    result = dag_maker.run()

    assert result.success
    assert result.xcoms == {"produce": 21, "consume": 42}
    assert result.order == ["produce", "consume"]

pytest

dag_maker.run() executes every task in dependency order and returns an inert DagRunResult snapshot: states, xcoms, errors, order, and per-task access via result["task_id"]. Single tasks run with dag_maker.run_ti("produce"), and pytest_airflow_in_a_box.matchers supports one-expression bulk assertions like assert result == {"produce": succeeded(21), "consume": succeeded(42)}.

The pytest11 entry point registers the plugin automatically -- no pytest_plugins declaration needed. See the documentation site for the full dag_maker/run/run_ti surface, sessions, DB-free task execution, deferrable operators, the REST API fixture, and bundled smoke checks.

Why not...

• dag.test() -- Airflow's own built-in helper runs one Dag end to end, but it is not a pytest plugin: no fixtures, no isolated metadata database, no xdist parallelism, no REST API testing
• upstream tests_common -- the harness Airflow's own core test suite runs on; it targets testing Airflow itself, not published as a package for testing DAG-author code
• Flowminder pytest-airflow -- an inverse concept (runs pytest suites under Airflow, rather than testing DAGs under pytest) and unmaintained
• airflow-pytest-plugin -- generates JUnit-XML dashboards from DAG runs; not aimed at isolated, fixture-driven unit testing

Requirements

• pytest 8 or newer
• Linux or macOS for Airflow-backed tests

Apache Airflow does not support native Windows installations. Windows development should use WSL2 or the included devcontainer; platform-independent package checks alone do not imply full Windows Airflow support.

The released compatibility matrix is exercised in CI against every combination below, using Airflow's published constraints files:

On the 2.x family, run_task, cap_structlog, and the REST API fixtures fail with actionable errors naming the 2.x alternative; the requires_airflow2/requires_airflow3 markers auto-skip on the other family so one suite runs green on both sides of a migration. The 2.x tier is exercised through the end-user consumer contract (tests/enduser, marked compat) rather than the full internal suite.

Installation

uv add --dev "pytest-airflow-in-a-box[airflow3]"
pip install "pytest-airflow-in-a-box[airflow3]"

The plugin does not depend on Airflow directly: the Airflow 2.x monolith and the 3.x core both install the airflow package, so a hard plugin pin would corrupt whichever family you did not choose. The airflow3 extra pins apache-airflow>=3.1,<4 (the meta-package resolves a coherent core + task-sdk pair). Projects that already pin Airflow themselves -- for example through Airflow's published constraints files -- can install the plugin bare:

pip install pytest-airflow-in-a-box

The airflow2 extra (apache-airflow>=2.7,<3, carrying an explicit python_version < '3.13' marker because Airflow 2.x never supported 3.13 -- on newer interpreters the extra resolves to nothing and the plugin's runtime check names the fix) installs the certified Airflow 2.x compatibility tier (#25): dag_maker (including whole-DagRun execution through dag_maker.run()), run_ti, full_dag_bag, clear_db, seeding, and the bundled smoke checks run against 2.7.3, 2.8.4, 2.9.3, 2.10.5, and 2.11.2. The marker is the family-wide cap; 2.7.3 and 2.8.4 cap lower still, at 3.11, and the plugin's runtime check names the offending release. Requesting both Airflow extras together fails at resolution for pip and uv alike, since the apache-airflow version ranges are disjoint.

The pytest11 entry point loads the plugin automatically. Consumer projects do not need to add a pytest_plugins declaration.

The bundled pytest plugins are intentional runtime dependencies. pytest-xdist is part of the supported execution model: controller bootstrap state and worker-scoped artifacts are coordinated for parallel runs. pytest-timeout backs up Airflow's per-file Dag parse watchdog with a corpus-scaled deadline on every bundled smoke item, so whichever worker produces the shared corpus cannot wedge the test session outside the per-file parser boundary.

The plugin is inert on runs without Airflow-facing tests: session startup only prepares a disposable run directory and AIRFLOW__* environment variables. Airflow itself is imported and the metadata database migrated lazily, on the first test that carries a db_test/api_test marker or uses a database-backed plugin fixture. A pytest -k unrelated run in a shared venv never pays the Airflow import or migration cost. Tests that touch the metadata database directly (their own create_session calls, for example) without a plugin fixture must carry db_test to trigger initialization.

To disable the plugin entirely for a run:

pytest -p no:pytest_airflow_in_a_box

GitHub Action

A composite GitHub Action wraps the constraints-pinned uv + Airflow setup this repo's own compat matrix uses, for a Dag repo's own CI. It provisions the environment and stops -- you always write the invocation, so the example below shows several distinct features of the plugin rather than baking one blessed command into the action.

- uses: actions/checkout@v5
- uses: nredd/pytest-airflow-in-a-box/action@v0
  id: airflow-env
  with:
    airflow-version: "3.3.0"
    python-version: "3.12"

# Plain unit tests
- run: ${{ steps.airflow-env.outputs.python-path }} -m pytest

# Bundled smoke checks (Dag import + parse-time diagnostics)
- run: ${{ steps.airflow-env.outputs.python-path }} -m pytest --airflow-smoke

# Migration outcome diff: record a baseline, then compare on a later run
- run: ${{ steps.airflow-env.outputs.python-path }} -m pytest --airflow-record=baseline.json
- run: ${{ steps.airflow-env.outputs.python-path }} -m pytest --airflow-baseline=baseline.json

# The `airflow-migration-diff` console script, via the venv-path output
- run: ${{ steps.airflow-env.outputs.venv-path }}/bin/airflow-migration-diff --project-dir .

Drop it straight into a strategy.matrix loop -- it's a single step with scalar inputs:

jobs:
  test:
    strategy:
      matrix:
        airflow-version: ["3.2.2", "3.3.0", "3.3.1"]
        python-version: ["3.11", "3.12", "3.13"]
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v5
      - uses: nredd/pytest-airflow-in-a-box/action@v0
        id: airflow-env
        with:
          airflow-version: ${{ matrix.airflow-version }}
          python-version: ${{ matrix.python-version }}
      - run: ${{ steps.airflow-env.outputs.python-path }} -m pytest

Outputs: python-path (the provisioned venv's python), venv-path (the venv directory, for console scripts), and report-dir (the absolute report directory, for an upload step). The examples above pin @v0: release.yml moves a v<major> tag (v0 while pre-1.0, v1 once 1.0.0 ships) to the latest published release on that major line, so @v0 tracks the newest 0.x. Pin a full release tag (e.g. @v0.7.0) for an exact, non-moving reference.

Migration diff orchestrator

airflow-migration-diff is a console script that uv-provisions a disposable Airflow 2.x environment and a disposable Airflow 3.x environment, records outcomes on each, and prints the categorized migration diff -- one command that tells a migrating team exactly what breaks:

airflow-migration-diff --project-dir . -- -k "not slow"

Exit code 0 means no regressions, 1 means at least one was found, and 2 means the orchestrator itself failed (missing uv, a provisioning failure, and the like). See the documentation site for the full option reference.

Documentation

Task execution, deferrable operators, DB-free execution, Variable/Connection seeding, structlog capture, Dag collection, configuration overrides, smoke tests, report artifacts, database backends and cleanup, the live REST API, the migration outcome diff, markers, and diagnostics are all covered on the documentation site.

Development

uv sync
uv run prek install
make all

Run the GitHub Actions workflow locally on Linux with act:

act pull_request

act cannot reproduce native macOS or Windows behavior. See CONTRIBUTING.md for the full contribution workflow and the issue tracker for open work.

License

Apache License 2.0. See LICENSE, NOTICE, and PROVENANCE.md.

Manifesto

In 2024, I learned that my team was abandoning Jenkins for our nightly regressions. A righteous tear rolled down my cheek when I heard the replacement was Airflow: a Python-native workflow platform. As a lover of all things slick and hyper-engineered, I was overjoyed to rewrite all those DISGUSTING unversioned shell scripts into a beautiful library of documented, statically-analyzed, and unit-tested code. Fast forward a few months--I have some crazy 500+ task DAG templates underway (for convoluted semiconductor design methodologies) that were IMPOSSIBLE to fully verify outside of a live Airflow instance. I yearned for a far-off land where I could develop alone in my teched-out Python cave, talk to absolutely no one, and ship complete Methodologies without a whisper in the night. This plugin is the closest thing we have 🫡