Add pytest-mrt under Testing > Database Migration Testing

[croc100]

What is pytest-mrt?

pytest-mrt is a pytest plugin and CLI tool that verifies Alembic and Django database migrations are safely reversible.

It catches rollback failures before they reach production:

• Detects missing or no-op `downgrade()` implementations
• Verifies schema is fully restored after rollback
• Seeds real rows and confirms data survives the round-trip
• Static analysis for 44 patterns across Alembic and Django (`DROP TABLE`, `RemoveField`, `RunSQL` without reverse, and more)
• `# noqa: MRTxxx` per-line suppression (ruff/flake8 convention)
• 6 built-in default tests auto-injected with zero config

Why a new "Database Migration Testing" subsection?

There is no existing category for database migration testing tools. Migration rollback safety is a real, common pain point — many teams have been burned by `downgrade()` functions that look correct but silently fail. This is a distinct niche from general testing frameworks or database drivers.

Requirements met

• Actively maintained (v1.2.0, June 2026)
• Available on PyPI: `pip install pytest-mrt`
• Open source (MIT)
• Documented: https://croc100.github.io/pytest-mrt