Migrate remaining tests to `pytest`

[Taragolis]

Body

All tests for Apache Airflow are run using pytest. We have about 80 tests modules which still use unittests runner for pytest , initial plan was "convert all unit tests to standard "asserts" semi-automatically, but this will be done later in Airflow 2.0 development phase. That will include setUp/tearDown/context managers and decorators.", see: Writing Unit Tests

Personally I do not have a free time to complete this tasks, if someone would like to work on one (or many) parts of this Task just let us know in comments or create a PR with reference to this Issue.

For keep in track remaining tasks for migration to "native" pytest runner I split it by separate phases

Phase 1: Migration unittests to pytest

1. Replace unittests by pytest
2. Replace @parameterized.expand by @pytest.mark.parametrize

Example how it done previously: https://github.com/apache/airflow/pulls?q=is%3Apr+migrate+tests+pytest+is%3Aclosed+

Always

• Migrate remaining tests/always to pytest migrated some part of test always to pytest #29375

CLI

• Migrate remaining tests/cli to pytest migrating from unittest to pytest tests cli file #29354

Other

• Migrate remaining tests/operators to pytest Migrated operators tests to pytest #29377
• Replace @parameterized.expand by @pytest.mark.parametrize in tests/callbacks migrated callback tests to pytest #29373

Providers

• Google (GCP)
  • Migrate remaining GCP operators tests tests/providers/google/cloud/operators to pytest Migrate tests in google/cloud/operators from unittest to pytest #29775
  • Migrate remaining GCP transfers operators tests tests/providers/google/cloud/transfers to pytest migrated tests/providers/google/cloud/transfers to pytest #29757
  • Migrate remaining GCP sensors tests tests/providers/google/cloud/sensors to pytest Migrate tests in google/cloud/sensors from unittest to pytest #29642
• Amazon (AWS)
  • Migrate remaining AWS tests tests/providers/amazon/aws to pytest Migrated tests/providers/amazon/aws to pytest #29758
• Apache Flink
  • Migrate Apache Flink tests tests/providers/apache/flink to pytest migrated all providers/apache/flink to pytest #29604

Phase 2: Ban unittests runner

It should be done after Phase 1.

This also include remove parametrized package, all features already exists in pytest core, see: How to parametrize fixtures and test functions

• Remove all unittests.TestCase usage in tests/test_utils, as far as I know right now only one place where we use it. Remove unittests.TestCase from tests/test_utils #30685 (review)
• Ban inheritance from unittest.TestCase it could be done by different ways:
  • Create collector hook which raise an error if detected unittests.TestCase, the opposite how builtin pytest plugin works, see: unittest.py::pytest_pycollect_makeitem
  • Develop pre-commit hook Add pre-commit hook to ban usage of unittest.TestCase in unit tests #30775
• Disable builtin unittests plugin by add -p no:unittest in pytest.ini adopts section, this step only disable discovering classes based on unittests.TestCase.

Some useful stuff

I use this command to find any remaining usage of unittests.TestCase and parametrized

# All modules which potentially use  unittests.TestCase
❯ grep -rl 'TestCase' ./tests | sort | uniq -c | sort -nr

# All modules which potentially use parameterized
❯ grep -rl 'from parameterized' ./tests | sort | uniq -c | sort -nr

# List of providers which potentially use  unittests.TestCase 
❯ grep -rl 'TestCase' tests/providers/ | cut -d"/" -f4 | sort | uniq -c | sort -nr

Committer

• I acknowledge that I am a maintainer/committer of the Apache Airflow project.

[Abhishek-kumar-ISM]

I would like to work on this issue. I am checking the code for this.

[Abhishek-kumar-ISM]

I have migrated one file from unittest to pytest.

PR => [https://github.com//pull/29354]

[Abhishek-kumar-ISM]

@Taragolis did changes as you asked, regarding parameterized.expand in test cli files.

[Taragolis]

@Abhishek-kumar-samsung You could comment in PR, you really don't need to ping anywhere 🤣
I've have a full time job (as many other contributors of Airflow) so this is regular thing if you do not have feedback quick, but sooner or later I or someone else look on PR and related issues 👍

[Abhishek-kumar-ISM]

Oh sorey @Taragolis this is my first time with open source thats why i am not more comfortable with procedure, will take care next time.

[Abhishek-kumar-ISM]

@Taragolis tests in always are also completely migrated to pytest as per me. Only mock objects of unittest are still used, other things migrated.

So i think you can tick mark that task also.

[Taragolis]

Thanks for contribution and help with migrations 💯 🥇

Only mock objects of unittest are still used, other things migrated.

That is fine we do not have plan to remove them, even pytest-mock use internally unittests.mock