DAG unit testing

A sample unit test for a Python DAG.

Code sample

Python

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from airflow import models
from airflow.utils.dag_cycle_tester import test_cycle


def assert_has_valid_dag(module):
    """Assert that a module contains a valid DAG."""

    no_dag_found = True

    for dag in vars(module).values():
        if isinstance(dag, models.DAG):
            no_dag_found = False
            test_cycle(dag)  # Throws if a task cycle is found.

    if no_dag_found:
        raise AssertionError("module does not contain a valid DAG")

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