Key Aspects of Non-Functional Testing for Applications

Introduction

Non-functional testing is an important process that focuses on aspects of an application not directly related to its functionality but critical for its quality and usability. Unlike functional testing, which checks whether all program functions work correctly, non-functional testing evaluates parameters such as performance, security, usability, and compatibility. It ensures the application works stably across different devices and conditions, creating a better user experience.

Here are some key aspects of non-functional testing that help assess and improve an application:

Compatibility

Cross-Device Testing

The goal of this test is to ensure the application works correctly on various devices with different screen sizes and resolutions. It’s important that the interface adapts to each device type and displays properly.

Operating System Compatibility

Testing must confirm that the application functions without issues on different operating system versions. It’s especially important to check performance on the minimum supported version and the latest OS version, as frameworks or interface elements may behave differently across versions.

Device Orientation (Landscape/Portrait)

This test checks how the application responds to changes in device orientation. For example, if the app supports only portrait mode, it should not display the interface in landscape mode when the screen is rotated.

Interface (Light/Dark Theme)

It’s necessary to ensure that when switching themes, all interface elements, fonts, and images display correctly and match the selected style.

Language Support

It’s important to verify how the application works in different languages. Ensure translations are accurate and all supported language characters display correctly.

Currency and Date Format

The application should properly adapt currency, date, and time formats based on the user’s local settings.

Right-to-Left Language Support

For languages like Arabic or Hebrew, verify that the interface displays and functions correctly with the specific features of these languages.

Performance and Stability

Slow Internet Connection

Testing should confirm that the application continues to work properly with a slow internet connection, maintaining functionality and minimizing delays.

Network Switching

Ensure the application remains stable when switching between different network types (e.g., from Wi-Fi to 4G/5G and vice versa) without losing connection.

Offline Mode

This test checks how the application works without a network connection. Verify that it saves data locally and notifies the user if some features are unavailable.

Handling Delays

The application should be tested for performance under various network delays, especially for apps like streaming video or real-time messaging, where delays impact user experience.

Network Failures

Ensure the application properly handles network failures, attempting to reconnect automatically or notifying the user about network issues.

Security and Privacy

Privacy Policy

The application must comply with data protection laws (e.g., GDPR, CCPA). It should include a clear privacy policy informing users about how their data is collected and used.

Age Restrictions

If the application has age restrictions, verify that it enforces them and prevents underage users from accessing it if required.

User Experience

User Interface (UI) Design

The application should provide an intuitive and user-friendly interface that displays and functions correctly on all device types and screens. Interface elements should be easily accessible and clear to users.

Accessibility

The application should be accessible to people with special needs. Ensure it supports features like voice assistance for visually impaired users to improve accessibility.

Application Lifecycle

When restoring the app from the background, verify that it returns to the same screen it was closed on, without losing important information or context.

Emoji Input

If a field (e.g., password field) should not support emoji input, ensure the application blocks this input.

Font Size

The application should properly support system font size changes, such as when a user increases the font size in iOS/Android settings.

Reliability and Stability

Stress Testing

This test simulates extreme usage scenarios to check the application’s limits. Ensure the app can handle high loads and continue functioning.

Maximum Data Volume

Test the application’s ability to handle large data volumes, such as big files or databases, to ensure it doesn’t crash during processing.

Data Integrity

Ensure the application maintains data integrity during various user actions and device states (e.g., online/offline).

Data Synchronization

If the application uses cloud storage, verify that data synchronization between devices works without issues.

Updates and Migrations

App Update and Database Migration

When installing a new app version with an updated database, ensure data migration happens correctly and information is preserved.

Application Update

Verify that user data and settings are preserved during an app update and that new features work correctly.

Cross-Platform Behavior

Cross-Platform Consistency

If the application is available on both Android and iOS, ensure it behaves consistently across platforms, except when specific features are required for one platform.

Analytics and Monitoring

Crash Analytics

Ensure the application is properly integrated with crash analytics tools (e.g., Firebase, Crashlytics) to track and fix errors.

User Behavior Analytics

Verify that the application correctly tracks user behavior (e.g., screen flows, clicks) while complying with all data privacy requirements.