elixir-testing

Testing Elixir background processes safely requires sandboxed database isolation. You can use Ecto.SQL.Sandbox in manual mode with start_owner!/2 and start_supervised!/1 patterns to ensure automatic cleanup and prevent transaction leaks across GenServers and Oban workers.

The best way to configure Ecto.SQL.Sandbox is using manual mode by default and selectively enabling shared mode via test tags. This strategy maximizes performance for fast unit tests while ensuring safe, isolated integration tests when concurrent database access is required.

Deterministic Oban testing involves separating job enqueueing from execution. You can configure Oban testing patterns to isolate worker behavior, ensuring background jobs do not execute unexpectedly during Ecto.SQL.Sandbox test runs and yielding predictable, reliable test outcomes.

Global shared mode degrades test performance and reliability by allowing unrestricted concurrent database access across all tests. Avoiding it and using selective shared mode via test tags maintains strict test isolation while preserving the speed of manual mode for standard unit tests.

Yes, you can use Ecto.SQL.Sandbox with Oban and GenServers. By leveraging start_owner!/2 for database ownership and start_supervised!/1 for process lifecycle management, tests achieve proper automatic cleanup and reliable database isolation for background processes.