RNTL or Detox for a navigation flow?

WHAT THIS TESTS: Whether you can match the testing tool to the goal and articulate the tradeoff between speed and fidelity.

A GOOD ANSWER COVERS: The answer is conditional. If the goal is to verify navigation logic, you can render the React Navigation navigator inside React Native Testing Library, simulate the press that triggers navigation, and assert that the destination screen's content appears and that route params were passed. This runs in Jest in seconds, needs no device, and is reliable in CI, making it ideal for the bulk of navigation coverage. If the goal is genuine end-to-end confidence, exercising the fully built app on a real or emulated device including native screen transitions, deep linking, permissions, and platform quirks, Detox is appropriate; it drives the actual binary and catches issues that a JS-only render cannot. A senior answer typically chooses RNTL for most navigation behavior and reserves the slower, flakier Detox suite for a handful of business-critical end-to-end journeys.

COMMON WRONG ANSWERS: Insisting only Detox can ever test navigation; RNTL handles navigation logic well. Claiming RNTL gives full end-to-end confidence, which it cannot because it does not run the real native app. Ignoring the cost: Detox is slower and more flaky and harder to maintain in CI.

LIKELY FOLLOW-UPS: How to render a navigator in RNTL, why Detox needs build configs and synchronization, the flakiness tradeoffs, and how to layer the test pyramid.

ONE CONCRETE EXAMPLE: For a list-to-detail flow, an RNTL test renders the stack navigator, presses a list row, and asserts the detail screen shows the selected item's title from the passed param, all in Jest. Separately, one Detox test launches the real app and walks the same flow on an emulator to confirm the native push animation and back gesture work end to end.