Test Coverage Techniques Every Tester Must Know

Are you a tester and want to optimize the process of test coverage? Well, then, this guide is for you.

Software development is beneficial, but it is also vulnerable to many faults. Poorly designed software degrades the user experience and creates many functional issues.

Creating usable products and testing them thoroughly is critical to utilizing a sound testing method. It aids in determining a product’s health. Various test coverage strategies aid in the creation of a testing plan. 

One of the most stimulating aspects of testing is determining when to quit. How much testing is sufficient? Should we attempt to test every aspect of our software or application?

Should we prioritize the places where issues are more likely to occur? Should we distribute our resources evenly throughout the apps or focus our efforts on the essential modules? This handbook will teach you the many test coverage strategies that every tester should be familiar with

What Is Test Coverage?

As the name implies, test coverage approaches are methods for increasing or maximizing test coverage. So the only thing that is left to do is define “test coverage.”

Test coverage is a software testing statistic that quantifies how much testing a collection of tests has completed. When you are executing the test suite, it will collect information about the sections of the program that are performed. This is done  to establish which conditional statement branches have been taken.

In basic words, test coverage is a method of ensuring that your tests are testing your code or determining how much of the code is exercised by conducting the test.

What Does Test Coverage Entail?

  • Recognizing the parts of a requirement that are not covered by a collection of test cases
  • Identifying a quantitative test coverage metric as an indirect quality control technique
  • Finding pointless test cases that don’t add to the coverage
  • Aids in the making of new test cases in order to expand coverage.

Advantages Of Test Coverage

Let us look at the advantages of app testing early and establishing your test coverage before diving into the various sorts of testing coverage methodologies.

  • Test Coverage aids in the early detection of any faults in your application. Identifying requirements and test case gaps now may save a lot of time and work later.
  • Test Coverage Aids in the Optimization of Regression Tests, Test Suite Augmentation, Test Case Prioritization,  and Test Suite Minimization. It also aids in the optimization of regression tests and test case prioritization.  As a result, the software development life cycle runs more smoothly and efficiently.
  • Redundancy should be avoided wherever possible. Such duplicate occurrences may be identified and reported by developers in order to make the code leaner.
  • Better test coverage equals fewer faults in production and user acceptability testing. This means fewer resources are available for testing. As a result, testing will get fewer resources.

Test Coverage Vs. Code Coverage

Test coverage and code coverage can often be used interchangeably. That’s understandable given the proximity of the phrases. Despite their similarities, these two names relate to distinct ideas, and they should not be used interchangeably. Let’s look at test coverage first.

Test Coverage

Test coverage is a QA department’s responsibility. It entails testing everything that has to be tested. 

A lower-level statistic is code coverage. It simply determines how well the unit tests cover the current code. Because test coverage is a technical issue, developers are the ones who are most concerned. Test coverage, on the other hand, may be thought of as a higher-level approach whose purpose is to identify how effectively an application is tested in terms of its requirements. As a result, test coverage is an issue not only for engineers but for everyone in the business that does testing, particularly QA personnel.

Code Coverage

A measure linked to unit testing is code coverage. The goal is to find the proportion of lines and execution pathways covered by at least one test case in the code. Aside from the unit test framework you currently use, you will likely require a specific coverage tool to assess code coverage.

If you use Mocha as your test framework, for example, you may use Istanbul to obtain code coverage. However, specific unit test frameworks, such as QUnit, offer coverage on their own. Line coverage is the most prevalent sort of code coverage. The percentage of the number of lines of code covered by at least one test is known as line coverage. Despite its use, this measure is often insufficient. This is because your application might have 100% line coverage but yet have untested cases.

Test Coverage Techniques Every Tester Must Know

Now that we have successfully covered the fundamentals of test coverage, it is now time to go into our list of test coverage approaches and techniques that every tester must know in order to enhance the test coverage process. So, let’s get started,

  • Product Coverage: The first approach that we will go over is product coverage, which basically means looking at test coverage from the standpoint of the product. Answering the questions like, “What aspects of the product have been tested?” is what product coverage implies.

Assume that you are evaluating a basic calculator application with only the four arithmetic operations available. Of course, you should double-check that the operations function correctly. However, this is insufficient. There are also more aspects to consider.

Is the calculator capable of handling really huge numbers? Or, to put it an alternative way, what range does it support? What will happen if the user does something that is unexpected, such as putting non-numerical characters into the text box or attempting to divide by zero?

You cannot claim your software covers the whole product until you check the situations listed above and others similar to them. 

  • Requirements Coverage: The most crucial of the strategies we’re going through today is requirements coverage. After all, even if your program performs admirably, it is meaningless if it fails to suit the needs of your consumers.

Returning to our previous example, Assume that our personal financial app was well evaluated, at least in terms of risk coverage, before being published. The situation with the inaccessible API was handled graciously, and everything works well again.

So it seems. Then the first reviews begin to arrive. They obliterate the application. What went wrong? In brief, while developing the test plans, the list of criteria was ignored. The program has to automatically sync with the users’ bank accounts, according to the regulations. Although the functionality was never deployed, it was definitely advertised.

As a result, requirements coverage is both the most fundamental and the most critical of the strategies discussed so far. It aids in the fulfilment of requirements, which is the whole point of software development.

  • Risk Coverage: Risk coverage is the third item on our list. As the name implies, this test coverage approach is all about analyzing and comprehensively testing the risks associated with an application. In a nutshell, the approach entails creating a list of the application’s risks and ensuring that they are covered by tests.

Consider the case of a smartphone app that assists users in managing their personal money. The program uses a third-party API to get financial data such as currency exchange rates or stock market share prices. The third-party API might go down, which is an apparent concern.

What is the expected behavior of the app in this situation? You must identify all of your application’s relevant risks and respond to the concerns they raise if you wish to claim that it is covered. 

  • Compatibility Coverage: This is linked to the idea of cross-browser testing. In other words, make sure your testing covers your app across several browsers and operating systems. You don’t have to test all conceivable combinations since it would be impracticable. However, find out which browsers are the most popular on Windows, Linux, macOS, iOS, and Android, and make sure you support those platforms.

Compatibility testing is divided into many categories, including:

  • Browser Testing: Cross-browser testing offers valuable information on how the program operates in other browsers. LambdaTest lets you perform live testing of websites and web apps across 3000+ browsers and devices, guaranteeing that you don’t miss out on your users’ favorite browser-device-Operating System combinations. 

It’s a scalable testing platform that may help your team by transferring your software evaluation requirements to the cloud. You can ensure that your website or web application is compatible with practically every browser and device currently on the market by utilizing LambdaTest to conduct real-time cross-browser compatibility testing. It allows businesses to test their web applications for responsiveness and capture complete screenshots while doing so.

  • Software compatibility: This entails comparing the software to other programs. Testing Microsoft Word compatibility with Microsoft Outlook is one example.
  • Hardware Testing: Different hardware configurations are used to test the application.
  • Mobile testing: It entails evaluating websites on a variety of mobile devices and platforms, such as Android and iOS.
  • Network testing: Evaluate an application’s performance under various network settings such as 3G, 4G, and Wi-Fi.
  • Boundary Value Coverage: Assume you have a feature that accepts numbers as input. However, it can only take numbers between 0 and 100 inclusively. In situations like this, you’d typically test at the border, as well as directly below and above it, to ensure the boundaries are thoroughly tested.

So you’d have to test with -1, 0, and 1 to get the minimal value (0). You’d try 99, 100, and 101 for the highest limit. As a result, the risk of off-by-one mistakes in your application is reduced.

The goal of boundary-value coverage is to ensure that such boundaries are checked throughout the application. 

  • Test Automation With AI: Finally, AI-assisted test automation is available.

The key distinction between this method and the others is that it is entirely automated. We’ve covered strategies that leverage automation but are still significantly dependent on human operations in earlier articles.

As the name implies, AI-Aided Test Automation is all about automation. It entails using AI-powered test automation technologies to elevate your testing methodology to new heights. Such technologies may help create self-improving test suites that use machine learning to learn and improve with each run.

As a result, you will have a robust and reliable test suite that not only delivers test coverage for your app but also test coverage that improves on its own over time.

How Should A Tester Make The Most Out Of The Test Coverage Technique? 

Choosing a test approach is critical for creating reliable goods. A solid test approach will aid in ensuring that the code is thoroughly tested. The test method entails using the various test coverage strategies stated above. In spite of the fact that each approach has its own set of advantages, the QA team must make the ultimate decision.

They may comprehend the features, hazards, compatibility difficulties, and product needs with good test preparation. Nowadays, test strategy approaches use artificial intelligence (AI) with self-correcting test cases that learn from and improve on prior executions, considerably decreasing test maintenance.

Any application’s robust testing approach is challenging to describe. However, if done correctly, it helps the company immensely and minimizes team work in the long term. They assist in tracking the progress and quality of your testing, as well as assisting the company in identifying flaws early on and deciding which tests to run and which to skip. These test coverage strategies address the many components of product testing and aid in the development of a comprehensive testing plan.

How Can A Tester Increase Test Coverage In A Short Amount Of Time?

To properly assess the assignments, each testing expert should be aware of the functions for the specified needs and specifications. The use of an automated tool is a tried and true method for getting more excellent coverage in less time. It facilitates the following outcomes:

  • Keeping a Checklist: Keeping a checklist for all of the fundamental interactions might aid in the inclusion of efficient chores.
  • Prioritization of Needs: Users should organize requirements into essential, major, and minor priorities, allowing them to concentrate on activities dynamically.
  • Analysis’ Impact: Determine and analyze the effects of the first releases.
  • Create test data using logic: For testing, we use a browser to generate test data. In these circumstances, it will be more successful if we can create test data straight from the database. Because database service calls are simple and quick, our test becomes faster and more reliable, similar to an API, by decreasing UI interactions.
  • Build Management: Product owners should maintain track of all current releases’ fixes, versions, and effects.
  • Run the most critical business test cases against all browsers every time: This offers running the essential business test cases against all browsers and running the low-priority test cases on a single browser. For each test suite, it provides a distinct browser.


Today, software testing is  considered as a critical component of the software maintenance life cycle. It is a method of enhancing software quality. Test coverage aids testers in improving the quality of test cases by filling in the gaps. It’s a crucial measure in software testing for determining how much testing a collection of tests has completed.

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