How do you ensure maximum test coverage?
By Shreya Bose, Technical Content Writer at BrowserStack - February 24, 2021
What is Test Coverage?
Test coverage monitors the number of tests that have been executed. Test cases are written to ensure maximum coverage of requirements outlined in multiple documents – FRS (Functional Requirements Specification), SRS (Software Requirements Specification), URS (User Requirement Specification), etc.
- Functional Requirements Specification – Describes the service that the software must offer, the software system, and its components.
- Software Requirements Specification – Describes how the software is expected to perform, as well as the expectations of stakeholders (managers, users, etc.) is must fulfill.
- User Requirement Specification – Describes what users want/need/expect from the system.
The test coverage report provides information about parts of the software where test coverage is being implemented. Essentially, it provides information about the tests executed on an application or website, letting QAs managers make informed decisions about resources, test duration, and other essential parameters. It is a black-box testing technique.
Types of Test Coverage
- Product Coverage
Product coverage answers the question: what parts of the product have been tested? Let’s take the example of an app that lets users create checklists or to-do lists for each day.
Obviously, testers would start by verifying the primary function – the ability to make and save lists. But they have to go beyond this feature to test secondary functions.
How many lists can be made and saved? Can the user set alarms to be reminded of tasks at regular intervals? Can the alarm be recurring for tasks that need to be repeated at intervals? Can lists be made in multiple languages? What happens when an unexpected user action occurs?
Increased product coverage leads to more features and functions being tested for expected performance standards and reveals what is going wrong at what juncture of the user experience.
Read More – Bug Tracking: A Detailed Guide
- Risk Coverage
Risk coverage evaluates risks that any application will face when being used by real-world users. Once the risks are known, testing can be structured to ensure that potential risks are not translated into actual negative consequences. When tests are designed to cover said risks, the software stands a much higher chance of attaining technical and commercial success.
Take an app for stock market investment, for example. Let’s say it uses a third-party API to search and retrieve financial data – exchange rates, stock prices, etc. If this API becomes unresponsive (a major risk), how would the app respond?
Risk coverage would take this into account and design tests accordingly to ensure the software does not become paralyzed and useless if such a risk occurs.
Read More: What is risk-based testing in agile?
- Requirements Coverage
Before commencing on developing any website or app, stakeholders draw up a requirements document that covers what the software seeks to provide its users. In other words, which of its customers’ needs is it fulfilling?
Think of the app from the last example – the stock market app. Let’s say it has been comprehensively tested and performs flawlessly in real user conditions. But on Google Play Store and App Store, the app gets mostly negative reviews. This would confuse its makers.
With further examination, developers might find that they missed out on including some aspects of the requirements document when designing test cases. One of them was the ability to automatically deposit profits from a sale to the user’s bank account. The tests missed out on the fact that this feature has not been incorporated into the app’s features.
Given the competitive nature of the digital market, this is something users are bound to expect. No one is going to sit around and manually transfer money from an app to their account. Requirements coverage would have ensured that the requirements document was scanned thoroughly and implemented in its entirety.
Did you know: Difference between Code Coverage vs. Test Coverage?
How do you ensure test coverage?
Start with putting together a comprehensive testing strategy that considers all the application’s requirements and the testing methods.
First, create a list of devices, browsers, and operating systems included in the test coverage matrix.
What is a test coverage matrix?
A test coverage matrix is created and utilized to ensure that software has been tested with sufficient thoroughness. It includes all categories of test coverage outlined in the previous section. The test coverage matrix traces and matches requirements from the client to the tests that must be run to verify software quality, and ensure that the requirements are fulfilled.
When devices/browsers/OS’es are updated, the list needs to be changed accordingly. The list should consist of device-browser-OS combinations popular in the market and those that customers of a particular software would be most likely to use. Looking for a cloud device farm? Check this out.
Next, plan the requirements of the tests themselves. How often should tests be run? Which tests should be run to verify which functions? What real-world conditions (unstable network, low battery, incoming calls) should the software be tested in?
Consider the duration of each test’s execution, the resources it requires, and match it to the deadlines and budgets in hand. This is where QA managers have to decide risk vs. resource and figure out the direction of testing.
Bear in mind that test coverage, no matter how expansive, can still leave room for some flaws to get through into production. This is why testing in production is just as necessary.
Additionally, set clear goals to work towards. Determine the breadth of test coverage required and the percentage of test coverage and code coverage essential to make the software a minimum viable product for release. In true Agile fashion, goals, and strategies have to be consistently evaluated, reworked, and improved to match user feedback and expectations.
- Expand Code Coverage
Code coverage is performed to verify the extent to which the code has been executed relative to each software component. It answers the following questions at the unit test level:
- Are there enough tests in the unit test suite?
- Do more tests need to be added?
How to calculate code coverage?
Code Coverage% = (Lines of code executed / total lines of code created) X 100
CI/CD tools ensure that code coverage is high since all code pushed to version control is automatically run through a series of tests. Try to keep code coverage at 80% or higher and strive to fill the gap by writing missing tests when possible.
High code coverage reduces the number of undetected bugs that might get through to end-users. However, bear in mind that code coverage doesn’t reveal other significant factors like code quality. That requires a human overview to some extent.
- Increase Test Automation
Naturally, to ensure that a considerable number of tests are executed within a tight deadline, manual testing alone cannot be depended upon. Automation testing, especially parallel testing, is required to run the requisite tests within days or even hours.
Read More: 10 Test Automation Best Practices to follow
The easiest way to run automated tests is to use a cloud-based testing service that enables automation on real browsers and devices. Automated Selenium testing is easy on BrowserStack’s cloud Selenium grid of 2000+ browsers and real devices. The grid facilitates parallel testing, speeding up their builds, resulting in faster releases. With pre-built integrations across over 20+ programming languages and frameworks, BrowserStack Automate fits easily into existing CI/CD workflows by providing plugins for all major CI/CD platforms.
- Maximize Device Coverage
Test on as many device-browser-combinations as possible. Each device model, browser, and OS has multiple versions that need to be taken into account.
It is best to choose and leverage a cloud-based testing platform like BrowserStack that offers access to the latest and legacy devices, browsers, and operating systems. As mentioned in the previous section, users can access 2000+ real devices and browsers to test on. For example, tests can be run on Chrome operating on a Samsung Galaxy S20, Firefox operating on Galaxy S20+, and the like. There are thousands of combinations to choose from. Try now.
Find out: How to test on the right mobile devices
Ensuring sufficient test coverage is essential to release software that meets users’ expectations. It establishes a high-quality user experience and keeps QAs from releasing bug-ridden software into the real world.