Testing the Reliability of Android Applications on Foldable Devices

Foldable devices introduce a class of problems that most Android apps are not designed to handle. The transition between folded and unfolded states is not just a visual change. It is a structural change that can affect layout, lifecycle behavior, and internal state. Many apps assume a stable screen configuration. Foldables break that assumption.

This work focuses on evaluating how well Android applications handle these transitions, and whether user state is preserved when the device changes form.

Approach

The process begins with manual testing. The goal at this stage is simple: interact with key features in an app, then trigger a fold or unfold event and observe what changes. In many cases, issues appear immediately. Screens reset, inputs disappear, or the app navigates away from the current context.

After identifying patterns manually, the process moves to automation using the Android emulator configured for foldable behavior.

The automated workflow follows a consistent structure:

• Launch the application and navigate to a feature of interest
• Perform a sequence of interactions to reach a meaningful state
• Dump the current UI hierarchy as XML
• Trigger a fold or unfold event
• Dump the UI hierarchy again
• Compare the two XML representations

The expectation is that the structure should remain consistent, aside from layout adjustments. Functional elements and state should persist.

Automation Details

Automation is implemented using Appium with the UiAutomator2 driver. Scripts are written to reliably navigate through application features and reach specific states before triggering configuration changes.

At key points, the script captures the UI hierarchy using Appium’s page source functionality. This produces a full XML representation of the current interface. These XML snapshots are then compared to detect structural differences.

This approach shifts the validation from visual inspection to structural analysis. Instead of checking whether a button looks correct, the test verifies whether it still exists in the UI tree and retains its role after the transition.

Findings

Across multiple applications, fold and unfold events frequently introduce instability. Common issues include:

• Loss of user input or navigation context
• Reinitialization of activities instead of preserving state
• Missing or duplicated UI elements after transition
• Inconsistent behavior depending on timing or interaction sequence

These issues indicate that many applications do not treat foldable transitions as primary events. Instead, they are handled as edge cases, often relying on default lifecycle behavior that is not sufficient for maintaining continuity.

Key Insight

Fold and unfold transitions should be treated as first-class state changes, similar to rotation or backgrounding, but with additional complexity. Developers should explicitly manage state across these transitions rather than relying on implicit behavior.

From a testing perspective, foldable devices require a shift in strategy. It is not enough to test static screens or linear flows. The focus must be on state preservation across dynamic configuration changes.

Conclusion

Foldable devices expose weaknesses in how applications manage state. By combining manual exploration with automated UI hierarchy comparison, it is possible to systematically detect these issues.

This approach provides a scalable way to test reliability in a space that is still underexplored. As foldable devices become more common, treating dynamic state transitions as core events will be essential for building robust Android applications.