How to Write Test Cases for Software
A test case offers a way of validating whether a software component is free of bugs and performing as it should. Many suggest that the benefit of a strong test case is that it can guide any user, prompting them to walk through the test steps and execute the actions required for validation. And it’s true that a test case should be able to do that.
At the same time, others purport that the objective of a test case is to automate steps to validate that a piece of software is free of bugs. After all, automating is the only way to rule out operator error.
In fact, there are several reasons automating test cases is preferable:
Regardless of your objective, it’s important to understand the following best practices for writing a test case.
Anyone can write a test case but you want yours to be strong, clear and able to meet your objectives as described above. Here are seven things to keep in mind when getting ready to write a test case.
When writing test cases, less really is more. If you’re writing a test case for the first time, you may feel overwhelmed with questions. You may wonder if every test case requires relationships? Or you may ponder how much detail is too much?
Templates outline steps to take and certain requirements for writing a test case. But depending on your comfortability with the material and the objectives you may choose to leave out some elements that you do not deem necessary to your test. And that’s ok.
Focus on keeping the test simple and clear, and don’t over complicate it by imposing unnecessary standards.
It’s important that a strong test case can apply to many different scenarios in which software needs to be validated. The idea is that a test case should offer longevity and provide value to the entire team. Keeping this principle in mind will help to save time re-writing test cases in the future.
Does it perform the way you want it to?
When you’ve created a test case look at it critically. Not just as a test case writer, but as an end-user. Even if your test case will be automated, it’s still recommended that you look at it through the lens of the person who will be implementing the test.
Taking this fresh perspective allows you to identify any pitfalls or vulnerabilities in the testing model and make the necessary adjustments to address them.
Creating strong naming conventions may not always be the first thing that crosses your mind when it comes to writing a test case. However, the title should promote a strong understanding about what it is you are trying to validate. For instance, if you are testing the shopping cart feature of an application, include Shopping Cart along with test identification information in the title.
The title needs to be strong, but that doesn’t discount the importance of a good description. Using this space wisely means defining your test in the description and including details such as the test environment, test data and importantly, test assumptions.
Including assumptions in your test helps ensure clarity. The same goes for preconditions that must be met before taking the test as well. Assumptions and preconditions include:
When it comes to writing test cases, the words “clear and concise” are used frequently. Use language that is simple and easy to understand, but which still meets the requirement of completeness in terms of the relevance of information included.
There are a few to choose from:
For the savvy developer, there are many ways to write a test case.
The key characteristics of each test case describe an action, an input, event or anticipated response. Because of the broad description and the various ways a developer can attack this type of project, working with a test case in levels helps to avoid duplication of efforts.
Level 1: At this level, test cases are written specs that are available and any usable documentation. These test cases are in their most basic state.
Level 2: Level 2 test cases are programmed via a more practical approach which takes into consideration system flow of an application and how it functions.
Level 3: At Level 3, you begin grouping like test cases and writing test procedures. The latter is the name given to a group of up to 10 cases.
Level 4: Automation is the order of the day at this level where you focus on minimizing human interaction for best results.
It’s expected that most test cases will contain roughly the same fields as follows:
This is a unique identifier for each test case. Typically it’s numeric.
The purpose should not be longer than two sentences outlining the objective of the test case.
This is where you include any conditions that must be met to run the test. This could include your assumptions and preconditions if you haven’t already stated them somewhere else.
These are elements used in a test case, including all variables and possible values, log in conditions and the like.
This is the place for detail. Include each step for completing the test from the end-user’s perspective.
What does a bug-free outcome look like? Describe the desired results from running the test.
Record the test outcome.
This is binary, pass or fail.
Include valuable information that will help the software developer debug.
Title: Shopping Cart – Add items to cart
Description: A registered user should be able to successfully add an item or item(s) to cart.
Precondition: The user must already be registered using their email address and chosen password.
Assumption: The user must be on the mobile app.
Test Steps:
Expected Result: Air Purifier item should be present in cart
Armed with the knowledge of how to write stronger test cases, you might wish to take things a step further by removing human error altogether. BMC offers a number of Application Deployment and DevOps Tools that help developers at all levels create new software, test and automate the process.
Let us help your DevOps team deliver applications quicker and with higher quality by providing self-service development capabilities that work within existing continuous delivery processes. For more information on how you can partner with BMC on testing and software development, contact us today.