Test Coverage Techniques Every Tester Must Know

Introduction

Conducting an error-free software development project has become the need of the hour but it seems to be as tricky as finding the needle in a haystack. And there is no point in launching software that features poor design doesn’t meet the expected user experience standards or features numerous functional problems. And above all, poor-quality software can certainly cost you an arm and a leg.

So this is why software development and software testing need to work in tandem. This is why the need for a solid testing strategy is required for good testing coverage. The following post is all about what is test coverage, why is it needed in the first place how is it beneficial in the long run and what are the top test coverage techniques every software tester needs to master.

So let’s begin with the basics,

What is test coverage?

I have come across several posts on test coverage, one which I was pretty intrigued by says that test coverage is a measure in software testing that assists well in determining the extent to which different types of tests are required to be executed successfully. To be extremely precise, test coverage is the percentage of application code and also it highly depends on whether the test cases cover all the code or not.

Test Coverage Formula goes something like this

Let's say you have 10 requirements and you need at least 100 tests to perform, then even if you run 90 out of 100, it is said you have completed 90% test coverage.

By conducting a successful test coverage you can:

• Identify any missing requirement from the test case collection

• Developing supplementary test cases becomes more easy

• Ensure quality using a quantitative way

• Seamless detection of fake test cases

Moreover, it is an indirect quality check method that assists well in identifying a quantitative measure of how much code you cover. Moreover, test coverage also assists well in additional test cases, which eventually increases coverage. Moreover, certain gaps between test cases and requirements can be identified. Defects can be spotted way earlier and lots and lots of grunt work can be eliminated which might get piled on in the later stage. And in the end, all you receive is a fine end product leading to enhanced customer satisfaction.

Now many of you have this misconception that test coverage and code coverage are quite the same. Well, code coverage is more related to a metric related to unit testing. So the percentage of lines and execution paths can be seamlessly covered with the help of one test case. Code coverage mainly measures how unit tests cover the existing code and test coverage needs to be conducted by an experienced software tester or quality analyst who understands the true significance of testing a software application.

Recently I happened to stumble upon an interesting Consortium for Information and Software Quality (CISQ) report which says the cost of poor-quality software has risen to $2.41 trillion and the numbers keep on increasing every single day. This means software testing in today's times is a non-negotiable factor.

As mentioned earlier, test coverage is all about measuring how much of the codebase is tested and it focuses on covering maximum application code, modules, functionalities, and requirements with the help of different test cases. So test coverage here is mainly the measurement of how much of the code in the application has been executed especially during the tests being conducted. Now do you think it is possible to achieve 100% test coverage? Of course not! So what testing teams must target is achieving the maximum amount of test coverage. By doing so, you will be able to have more and more confidence in the code and quality of the developed application.

And now we will be discussing the why part. Why is there a need for conducting test coverage or how is test coverage beneficial in the long run?

Benefits of Test coverage

1. Early detection of defects or errors

As the benefit suggests with the assistance of test coverage, all the unnecessary and unwanted bugs or errors can be identified and rectified prior. The need for comprehensive test coverage cannot and shouldn’t be ignored at any rate. Everything needs to be tested from inputs to outputs, boundary conditions, potential bugs, errors can be easily identified as well as resolved right before the application crashes down and becomes the worst nightmare for you.

Also, isn’t there a saying that prevention is better than cure? Well, in the software development realm, this is extremely true. Ignoring any such factor can result in multiple disasters.

2. Ensuring high-end functionality

The next benefit of considering test coverage is that by doing so you are ensuring high-end functionality. After all, you don’t want to get anything out of it after all this hassle. With proper test coverage, you are most likely to get rid of all kinds of bugs and errors, including the undiscovered ones as well. Moreover, this surely means that the developed software is performing as it is supposed to be and has met all the specific requirements leading to a more reliable and functional end product.

3. Enhanced quality of the software

Another benefit of conducting test coverage is you are bound to receive enhanced software quality. Since there are no bugs and errors to be found, the overall quality of the software developed will improve no matter what. Test coverage works as a true indicator to keep the software quality in check. A rigorously, well-tested product is a must, especially in today’s times. And not to mention with every improved quality, the overall user experience can be enhanced seamlessly.

4. Efficient regression testing

The next advantage of conducting test coverage is regression testing. Test coverage also ensures that all kinds of modifications and additions done to the existing software ensure that there will be no scope for any kind of defects, including both the new and existing ones. By conducting comprehensive test coverages, regression testing becomes way more efficient and effective.

Also, when you keep on running existing test cases again and again, it becomes way easier for developers to identify unintended side effects which can be significantly caused by any slight changes in the code. It’s all about ensuring that the system remains stable and error-free.

5. Elimination of Redundancy

Test coverage surely removes redundant cases. Yes, in one manner or the other, it is pretty useful to identify as well as eliminate different types of test cases that even don’t make any kind of sense for the current project. All that is required is for the software developers to report such cases and remove them right away to make the overall code much lighter.

For optimum results, it is extremely important to uncover any kind of misleading scenarios. The need for new test cases, newer lines, reduced bugs, and above all ample time, what else do you need?

In short,

• Identifying errors and bugs

• Identifying potential gaps in requirements and design specifications

• Enhances reliability, performance, and scalability

• Identify potential areas of improvement, assists well in the decision-making process

• All development bottlenecks can be identified

• Software quality is par excellence

• Minimize the risk associated with software changes

• Ensuring that the system performs well even after the changes are being implemented.

• Less chances of security breaches, and data loss.

So I hope now you know why there is a need to conduct test coverage. Now we will move on to the how part, how to conduct appropriate test coverage. Check out the top test coverage techniques that every software tester must know in 2024.

Top Test Coverage Techniques Every Software Tester Must Know

#1 Product Coverage

As the name strongly implies, this technique in particular speaks regarding which part of the product needs to be tested rigorously. For example, there is a counter that needs to be tested, it’s a simple application that can either increment or decrement a specific number. In simple words, it's like you add your favorite food items to the cart. Testing the operations of the counter is a must however, these aren’t the only aspect that needs to be taken care of in the product coverage.

Product coverage can be seamlessly increased by prioritizing requirements and preparing a simple checklist of testing all the required tasks or activities. Here implementing effective test automation is a must which can eventually reduce testing times significantly. One of the leading cloud-based test automation tools is Browser-stack which successfully enables users to set up the website for testing in a few simple steps.

• First, prioritize and define the requirements

• Create a potential checklist

• Implement effective test automation

#2 Statement Coverage

The next technique for conducting test coverage is statement coverage. Again much like its name, this one ensures that all the statements are combined in a well-secured code and have been tested at least once. Here you will come across all kinds of tests, executed and failed code blocks. Here is a small diagram for better understanding.

Here a test case is needed to cover all requirements. One test case means, one statement coverage and to be very precise, it takes way more than a single path, so chances are extremely high for writing multiple test cases to cover all the statements.

Why is there a need for statement coverage?

• To apply directly to object code and need not be required to process source code.

• It successfully verifies what written code is expected to do and not do.

The only issue here is it covers only the true conditions of every statement and doesn’t report in case the loop reaches the terminations.

#3 Risk Coverage

The next technique to consider is risk coverage. Here you can have a detailed estimation of what needs to be tested and how critical it seems to be. You will have a detailed idea of what’s happening and how negatively it can impact you. Now there are four kinds of scenarios:

• First - If it is very likely to have a high impact then it needs to be tested

• Second - If it's unlikely to have a high impact then it should be tested

• Third - If it’s more likely to have a low impact then it could be tested in case you have ample time

• Fourth - If it's unlikely to have a low impact and the test is too expensive for the value then it’s okay to skip.

Analyzing and choosing the right scenarios to test is what risk coverage is all about.

#4 Requirement Coverage

Another technique to master is requirement coverage. Yes, much like its name, it means whether the application meets the customer's requirements or not. Have you come across any such philosophy that says high-quality products are useless? The technique’s essence is also the same. It’s all about noticing whether the final product comprises all the predetermined features and functionalities and meets all the customer’s listed requirements or not.

Let's say, if you want to develop a product that ensures seamless travel bookings, then I am sure you will plan to develop an app featuring multi-city flight bookings which means requirement coverage is a must here.

#5 Compatibility Coverage

And lastly, we have compatibility coverage. Device fragmentation is a huge concern these days which can lead to severe compatibility issues. In the present scenario, you will come across at least 9000+ devices, 8 browsers, and 21 operating systems available. Imagine testing across all kinds of device browsers. It’s a mammoth task. The compatibility test coverage technique ensures that the application is compatible across browsers, different hardware, networks, mobiles, and operating systems.

Certain Points to Consider as a Software Tester

• Keeping updates in mind

• Quality is way better than quantity

• No Redundancy

• Perform multi-degree testing such as unit testing, integration testing, system testing, etc.

• Easy Automation

Conclusion

And we are done for now! This is what test coverage is all about. Achieving 100% or maximum test coverage is simply great but doing just for the sake of it is no good. In the end, you will find yourself wasting time, money, and resources.

Test coverage can certainly assist in structuring the code better, writing simple codes, eliminating unused scripts, and above all, launching an application that delivers excellent value. It is advisable to seek reputable and renowned software testing companies that carry immense knowledge and experience in delivering the best possible solutions from their space.

I hope you find the following post worth reading. If yes, feel free to share among your peers and in case you still have any doubts regarding software testing development designing or any other aspect of the software development landscape feel free to mention them in the comment section below we will get back to you in a short period. Good luck with your future development projects