How to Improve Test Coverage for Your Mobile App

Testing and QA are critical to mobile teams. 88% of app users are willing to abandon apps based on bugs and glitches, according to Qualitrix. Figuring out the best ways to test and make sure that users get the best experience should always be a priority for mobile teams. But how do you measure how much of your app should be tested? And how do you test more of your app without delaying your release? This guide is designed to help you maximize test coverage for your mobile app using common strategies.

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What is test coverage?

Test coverage is the measure of how much of your app you tested with a set of test cases. This could also include the number of devices or OS versions that you covered. The more you cover, the higher the test coverage. The calculation for test coverage is:

Test coverage = (Number of coverage items tested / Total number of coverage items) * 100

Aiming for 100% test coverage would be ideal, but that isn’t entirely possible. Testing every possible aspect of your app, and testing on every device and OS version supported, would set your release back indefinitely. There is no "correct" percentage of test coverage you’re supposed to hit since every app is different, but 70% is considered a good number to aim for.

Now that we’ve defined what test coverage is, let’s look at the ways to improve it.

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Planning and targets

When approaching any form of testing, it's always very important to plan ahead. A well-structured plan will keep in mind a couple of important aspects:

• Capabilities of your mobile team
• Time constraints
• Planning as early as the design phase of the SDLC
• Setting the target test coverage goal that suits your app and team

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Critical components

As we’ve already mentioned, you’re probably not going to be able to hit 100% test coverage of your app. While planning and setting a realistic goal in mind, you need to make some tradeoffs. To maximize test coverage, you can choose to focus on your app's most used components, or the areas that the majority of your users will experience. These critical features are an essential part of your app, so make sure they are prioritized if you are put in a position where you have to choose.

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Code coverage

Code coverage is a measure of how much of your code is executed during testing. Compared to test coverage, code coverage is a measure of how much of your app's feature set is covered with tests. Code coverage is usually seen as the alternative to test coverage but they both serve different purposes. Trying to maximize both is again ideal, but resource consuming. It’s important to work with developers to pinpoint how you can increase code coverage as much as possible. By increasing your code coverage, it will in tandem increase your test coverage by assuring the quality of code underneath. The goal isn’t to use one or the other, but to try to increase code coverage as much as possible in service of test coverage.

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Device and OS coverage

As we have already highlighted, test coverage is just making sure a set of test cases work, but making sure they perform on a variety of devices and OS versions. For both Android and iOS devices, there is a huge range of behaviors and device capabilities. Planning which devices and OS versions need testing will save a lot of time and increase your test coverage as well. Consider using emulators and similar tools as they will help you test various devices simultaneously and save a lot of time and resources. It’s also important to know your target audience and what devices and OS versions they will be more likely to use.

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Test automation

Test automation is becoming an indispensable part of testing and QA. There are plenty of repetitive tests that can be performed with automation and performed quickly as opposed to manual testers repeatedly doing them. This depends on your test requirements, but utilizing test automation properly will help you increase test coverage while saving you a lot of time. It’s important to remember that test automation should not be considered an all-encompassing replacement to manual testing, but as an assisting tool to cover more repetitive and mundane test cases whenever possible.

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Manual testing

When focusing on increasing test coverage, it could come at the cost of the quality of tests themselves. We can never overstate the importance of getting your app tested "in the wild". Depending on your plan, this can be done with alpha and beta releases, rigorously testing on real devices, or using the app yourself as much as possible. Having feedback tools to be able to log crashes and bugs will go a long way to effectively test your app. Apps behave differently when they’re fighting for RAM with other apps on a weak device, or struggling with bad network connectivity at random times to connect to your app. It’s important to keep all these factors in mind while trying to increase your test coverage and release a quality app.