What Is a Test Case and How to Write It? (Examples)

In the world of software testing, test cases are your trusty guides, leading you through the intricate maze of code and functionality. They hold the key to uncovering the software’s secrets, ensuring its performance and reliability. With each test case, you embark on a quest, navigating through steps and inputs, seeking out bugs, and verifying expected outcomes. Armed with these powerful tools, you become a hero dedicated to delivering flawless software.

Come on, let’s understand what test cases are and their utmost importance in the software development process. 

What Is Test Case?

A test case is a documented set of instructions that outlines the steps to be taken, the expected outcomes, and the necessary data for testing a specific functionality or feature of a software application.

Importance of Test Cases

Test cases are crucial components of the software development lifecycle due to several key reasons. First and foremost, test cases ensure the quality and reliability of the software.

Secondly, test cases serve as a form of documentation, providing a clear and concise description of the expected behavior of the software under various scenarios. 

Furthermore, test cases promote collaboration and effective communication within development teams. They provide a common ground for developers, testers, and other stakeholders to discuss and agree upon the desired behavior of the software. 

Test cases also contribute to cost savings and time efficiency. By finding and fixing bugs early in the development cycle, test cases help prevent these issues from propagating to later stages, such as integration or production environments. 

Lastly, test cases enhance customer satisfaction and confidence in the software.

How to Write Test Cases

Follow the below 10 steps to write a test case:

• Clearly identify the scope and boundaries of the test scenario to ensure appropriate coverage.

• Write test cases clearly and concisely, using simple language and providing all necessary information for testers to easily understand and execute the tests.

• Familiarize yourself with various testing techniques and methodologies, such as boundary value analysis, equivalence partitioning, or decision tables. Apply the appropriate test design technique to derive test cases that effectively validate the system or feature.

• Assign a unique identifier to every test case. This helps in tracking and referencing test cases throughout the testing process.

• Maintain a requirements traceability matrix that links each test case to the specific requirement or user story it addresses. This provides visibility into the test coverage and ensures all requirements are tested.

• Provide a clear, brief, and detailed description of the test case, including the purpose, steps, and expected outcome. This helps testers understand the intent of the test and ensures consistent execution.

• Specify any necessary preconditions or setup steps that need to be performed before executing the test case. Additionally, define any postconditions or cleanup steps that need to be followed after the test execution.

• Clearly define the expected outcome or result of each test case. This allows testers to compare the actual results with the expected ones and identify any discrepancies.

• Choose the appropriate testing techniques based on the nature of the system or feature being tested. This may include functional testing, performance testing, security testing, or any other relevant technique.

• Seek feedback from experienced testers or colleagues to review your test plan and test cases. This helps identify any potential gaps or improvements and ensures the quality of your test coverage.

Test Case vs Test Scenario

A test case and a test scenario are two different terms commonly used in software testing to describe different aspects of the testing process. While both are essential for ensuring software quality, they have different purposes and specific characteristics.

A test case refers to a specific set of conditions or inputs and the expected results that are defined to verify the functionality of a particular software feature or component. It is a detailed and concrete representation of a single test, often documented step-by-step.

On the other hand, a test scenario provides a broader view of the testing process by describing a high-level sequence of events or conditions that need to be tested. A test scenario defines the overall context or situation under which a set of test cases can be executed. It helps identify different paths or combinations of actions that need to be tested within a specific feature or system. 

Pro tip: Test cases are the building blocks of testing that focus on individual functionalities. In contrast, test scenarios provide a higher-level perspective by defining the context and sequences of events to be tested. 

Examples of Test Case

Here are a few test case examples.

Login Functionality:

Test case 1: Verify that a user can successfully log in with valid credentials.

Test case 2: Validate that a user cannot log in with invalid or incorrect credentials.

Test case 3: Ensure the system displays an appropriate error message when the login fails.

E-commerce Checkout Process:

Test case 1: Test the successful completion of a purchase by adding items to the cart, providing valid shipping and payment information, and verifying the order confirmation.

Test case 2: Verify that the system displays an error message when invalid payment information is provided during checkout.

Test case 3: Test the functionality of applying a discount code during checkout and confirm that the correct discount is applied.

Search Functionality:

Test case 1: Enter a specific keyword in the search bar and validate that the search results display relevant items.

Test case 2: Test the search functionality with multiple keywords and ensure the system returns accurate results based on combining keywords.

Test case 3: Verify that the search results are correctly sorted based on relevance, popularity, or other criteria.