To ensure the best user experience once mobile applications are released in the app stores, it is necessary to conduct performance testing on a variety of real devices in different environments. This is usually a challenging task due to the high cost and management associated with the physical retention of many smartphones and tablets for testing. 

Fortunately, virtual device farms have come as a solution that is both affordable and enables developers complete access to hundreds of physical devices located in remote places. In this article, we outline what is device farm testing, its benefits, and the steps to device farm testing.

Understanding Device Farm Testing

Device farms, also known as remote test labs or cloud-based services, let developers test mobile apps on physical devices in secure off-site data centers. This eliminates the need for costly in-house labs and dependence on limited local hardware.

Developers gain access to thousands of real Android and iOS devices in cloud data centers, enabling worldwide testing without maintaining local labs or simulators. Code is compiled directly onto the targeted devices, closely mirroring the end-user experience.

Telemetry, such as logs, videos, screenshots, and crash reports, are automatically captured for bug analysis and improvement. Integrating device farm testing ensures optimal app performance and quality across diverse real-world environments. 

Benefits of Using Device Farm Testing

There are several benefits to utilizing device farm testing during software development: 

• Access to thousands of real Android and iOS devices located in cloud data centers around the world. This expansive selection allows developers to test on an extensive range of devices that are difficult to procure and maintain in-house.
• Automated and self-healing provisioning of physical devices in the cloud reduces maintenance effort and eliminates dependencies on human operators or local infrastructure. Tests can run continuously at any scale without exhausting internal resources.
• Performance metrics and result analytics are captured automatically during tests and stored in a centralized cloud-based reporting platform. Insights across a large matrix of variables like device types, OS versions, geographic regions, and error conditions facilitate targeted optimization efforts.
• Advanced networking capabilities allow the simulation of varied real-world conditions like spotty connections, low bandwidth, and intermittent connectivity that are nearly impossible to accurately model with virtual emulators. This surfaces issues only visible in live field usage.
• Integrations with popular CI/CD tools and development frameworks facilitate the seamless incorporation of device farm testing into existing workflows. Tests are triggered automatically on code commits for quick feedback cycles.

Automated Testing Strategies

Creating automated test scripts is key to efficient large-scale testing in a device farm. While manual testing will always have its place, automation allows much more work to be done in less time. Here are some recommendations:

• Use a test framework like Appium or Espresso that supports driving many devices simultaneously via a Selenium or Appium Grid server. This parallelizes script execution.
• Focus test cases on key user flows, API integrations, and edge conditions rather than cursory “smoke tests”. Precision matters more than breadth when resources are limited.
• Structure tests modularly using page object models, data-driven approaches, and other best practices for reliable, maintainable scripts.
• Instrument test code to record performance metrics, take screenshots of failure, and log extra details to help with debugging across many concurrent runs.
• For repetitive checks, consider injecting test data once and validating expected outcomes rather than rebuilding the app between each assertion.
• Consider load/stress testing as a separate automated set of scripts to validate behavior under heavy simulated user loads.

The Role of Manual Testing

While automation allows vast testing scale, manual techniques are still needed to uncover certain types of issues. Some best practices include:

• Leverage a device farm’s remote hands feature for on-device debugging. Get crash logs, step through code, and reproduce bugs interactively.
• Manually exercise edge cases that are difficult to cover through scripts like complex gestures, nuanced UI interactions, and intermittent connectivity edge conditions.
• Try “poor network” simulations to test error/loading state handling when network conditions fluctuate.
• Evaluate the overall user experience by going through primary tasks and experiencing the “feel” of using the app. Look for rough edges.
• Involve testers without development context to get fresh eyes on usability, discoverability, and onboarding processes.
• Simulate real-world multi-tasking by quickly switching between apps or interrupting tasks to test resiliency.
• Physically rotate devices or even emulate being in a moving vehicle to test dynamic layout/gesture handling.

When to Use Device Farm Testing

While emulators have their place, using a device farm allows certain issues to be uncovered that simply would not appear during emulated testing. Some key scenarios where a remote test lab adds value include:

• Performance optimization: Measuring things like app launch times, response to user input, frame rates, and memory usage across a variety of hardware helps track down performance bottlenecks.
• Cross-device compatibility: Testing things like layout rendering, gesture handling, and peripheral support (like cameras) on many real devices is important for ensuring compatibility.
• Regional device variability: Factors like carrier-specific mobile network configurations, location services, and even device CPU/RAM differences between market regions require a diverse device matrix.
• Beta testing: Releasing early pre-release builds on a remote test lab allows gathering feedback from a large audience, catching major issues before app store publication.
• Edge case validation: Fringe devices with older OS versions, low-end specifications, or other non-mainstream configurations can still be tested rather than dismissed.

Steps for Testing on Device Farms

Here are the steps for testing on device farms:

• Design test scenarios and cases to cover critical user flows, localization, security, and variations in device/OS models. Prioritize tests that exercise key app functions across a wide range.
• Configure a testing framework that can run automated checks at scale, such as Unity, Espresso, or XCTest, and script test cases within it. Ensure proper setup for monitoring, logging output, and failure handling.
• Establish meaningful success/failure criteria and track baseline performance metrics to determine the health of each release. Automate collection of diagnostics data like network traces and memory profiles.
• Select target devices from the farm’s extensive catalog that represent a cross-section of your real-world user base. Group devices into suites matched to the need of specific test cases.
• Set up the continuous integration pipeline to automatically run necessary pre-build steps, upload the test code/app, trigger remote execution on commits/schedules, and publish results.
• Within the farm’s web console, monitor tests in progress, remotely access live devices if needed, and review detailed logs/reports on failures. Perform root cause analysis and debug interactively as tests run.
• Run full test suites with each code change to validate the lack of regressions. Periodically re-run benchmarks to verify past optimizations upheld over subsequent releases.

Challenges While Testing And How Device Farms Help

While testing is an essential component of the software development life cycle, it is not without its challenges. Let’s examine how device farms can address those issues.

Limited Device Coverage

Testing mobile apps across the wide range of devices used by consumers presents a major challenge. With new phones and tablets released constantly in varying screen sizes, processors, and operating systems, it’s nearly impossible for any organization to maintain an in-house lab with physical possession of every relevant device. Device farms solve this by providing access to tests on hundreds of devices at once, eliminating limitations on what can be tested on. Their expansive device matrix helps ensure maximum compatibility and that no audience is overlooked.

Reliance on Emulation Makes Things Unrealistic

While emulators serve an important purpose, they do not replicate the vast diversity of real mobile hardware. Factors like inconsistent performance based on device age, network configuration differences between regions, and variance in processing power cannot be fully tested in emulation alone. Even more intermittent issues like GPS or Bluetooth bugginess that only arise under certain environmental conditions will likely be missed. Device farms allow testing precisely on actual physical devices to better mimic the complex real-world environment apps must function within.

High Infrastructure and Maintenance Costs of In-House Labs

Setting up an effective in-house mobile website testing or app testing lab requires substantial upfront investment and ongoing operational expenses. Not only are there hardware costs to procure a wide range of phones and tablets, but dedicated lab space, tools for test automation, staff resources, and maintenance are all needed. Compared to this, device farms provide an affordable pay-as-you-go model with no long-term commitment and infrastructure already set up by experts.

Manually Updating OS Versions is Tedious

Keeping physical devices updated to the latest operating systems is a constant chore, yet critical for ensuring compatibility. Any time a new OS version is released, IT staff must manually flash updates on all in-house devices. Device farms take this maintenance burden away as their devices are always kept up-to-date automatically by their systems.

 LambdaTest for Device Farm testing on Cloud

LambdaTest’s cloud-based device farm provides a compelling solution for mobile application testing across various real devices. Maintaining a physical lab with the latest smartphones and tablets would be far too expensive and time-consuming for most organizations. 

This platform gives access to over 3000+ real Android and iOS devices, all accessible on-demand through their user-friendly testing dashboard. Testers can easily install app builds remotely, execute both manual and automated test cases, and view results and logs.

What stands out is their breadth of device coverage. Being able to test on the full range of devices currently in use, from low-end older models to the newest flagship phones, ensures applications are compatible and perform well for all users. The detailed real-device information makes problem identification easier compared to vague emulator environments. 

LambdaTest also handles all device maintenance and updates, so testers know the environment accurately reflects what users will experience. With pricing based on actual test minutes used rather than monthly fees, it provides a very cost-effective solution.

Conclusion

While emulators are useful for some testing scenarios, relying solely on them risks overlooking real-world device variability and usage context effects. Integrating robust device farm techniques allows shipping consumer-grade experiences by validating software in conditions that closely mimic end users. 

Proper planning, automated infrastructure as well as hands-on investigation, and monitoring tools make the most of these remote test capabilities. Following industry best practices, a well-executed test strategy using an on-demand device cloud prevents issues and keeps customers happy by catching problems before they ever encounter them.