Principle:Apache Airflow Local Testing
| Knowledge Sources | |
|---|---|
| Domains | Testing, Quality_Assurance |
| Last Updated | 2026-02-08 00:00 GMT |
Overview
A validation process for loading, parsing, and testing DAG files before deployment to a production Airflow instance.
Description
Local Testing ensures DAG files are syntactically correct, structurally valid, and produce expected behavior before deployment. The DagBag class is the primary mechanism for loading and validating DAGs — it parses Python files, resolves imports, constructs DAG objects, and reports errors. The CLI command airflow dags test provides an additional layer of testing by executing a full DAG run locally.
Usage
Use local testing during DAG development to catch errors early. Run DagBag validation in CI/CD pipelines to prevent broken DAGs from reaching production. Use airflow dags test for end-to-end execution testing of a specific DAG with a given logical date.
Theoretical Basis
Validation Layers:
- Syntax Check: Python file is importable without errors
- DAG Discovery: Files contain valid DAG objects (safe_mode checks for "DAG" or "airflow" strings)
- Structure Validation: Task dependencies form a valid DAG (no cycles)
- Scheduling Validation: Timetable is valid, start_date is set
- Runtime Test: Full execution with airflow dags test verifies task logic