A test case is a fundamental element of software testing that documents a sequence of steps to verify that a specific feature, functionality, or requirement of a software application behaves as expected.
Test cases serve as a blueprint, outlining the what, how, and expected outcome of each test scenario before the testing begins.
How to write effective test cases
Effective test cases are the backbone of a thorough and optimized software testing process. When done right, they empower testing teams to:
- Strategically plan what needs to be tested and outline the testing methods before execution.
- Make testing more efficient by providing important details like preconditions that must be met before testing and providing sample data for accurate test execution.
- Accurately measure and monitor test coverage, ensuring that all necessary aspects of the application are thoroughly examined
- Compare expected results with actual test outcomes to verify that the software is working as intended.
- Maintain a reliable record of past tests, to catch any regressions/defects or to confirm that new software updates have not introduced any unexpected issues.
Elements to consider when writing test cases
To write effective test cases, consider these four essential elements:
1. Identify the feature to be tested
Determine which features of your software need testing. For instance, if you are testing your website’s search functionality, pinpoint the search feature as a focus area for testing. Clearly defining the feature ensures that your test cases target the correct aspect of the software.
2. Identify the test scenarios
Outline the scenarios that can be tested to verify every aspect of the feature. For example, when testing your website’s login feature, possible test scenarios include:
- Logging in with valid or invalid credentials
- Attempting to log in with a locked account
- Using expired credentials
Ensure that you identify expected outcomes for both positive and negative scenarios. For instance, a successful login with valid credentials should redirect the user to their account page, whereas invalid credentials should trigger an error message and deny access.
3. Identify test data
Specify the data needed to execute and evaluate each test scenario. For example, in a login test scenario involving invalid credentials, the test data might include an incorrect username and password combination. Proper test data ensures that your scenarios are realistic and replicable.
4. Identify the test approach
Once you have defined the feature, scenarios, and data, develop a strategic approach to testing. Consider the following:
- For new features, you may need to write detailed test steps to confirm specific functionality. For example, when testing a new checkout process on an e-commerce site, include steps like adding items to the cart, entering shipping and billing information, and confirming the order.
- If your testing is exploratory or focused on user acceptance, a test charter or mission statement may suffice. For instance, during user acceptance testing of a new mobile app feature, your mission might be to verify that the login process is user-friendly and meets end-user needs.
Key components of a test case
When developing test cases, especially within agile methodologies, they function more as outlines than strict step-by-step instructions. Each test case should contain key elements that provide clarity and structure to the testing process. Here are seven essential components of a test case:
1. Title
The title should clearly reference the software feature being tested. A concise and descriptive title helps quickly identify the purpose of the test case.
2. Description (including the test scenario)
The description should summarize the objective of the test. It outlines what aspect of the software is being verified, ensuring that the test case’s purpose is understood at a glance.
3. Test script (if automated)
In the context of automated testing, the test script offers a detailed sequence of actions and data required to execute each functionality test. This script ensures that the test is performed consistently across different runs.
4. Test ID
Each test case needs a unique identifier, or Test ID, that follows a standardized naming convention. This ID makes it easier to reference, organize, and track test cases, especially when managing large volumes.
5. Details of the test environment
The test environment describes the controlled setup or infrastructure in which the software is tested. It includes information about the hardware, software, network configuration, and any other relevant conditions that may affect the test outcome.
6. Expected results
This section should clearly outline what the expected outcome of the test is. By documenting the expected results, testers can easily compare them with the actual results to determine whether the software behaves as intended.
7. Notes
The notes section is for any additional comments or relevant details that don’t fit into the other categories but are important for understanding or executing the test case. This could include specific instructions, reminders, or insights gained from previous testing.
Test case templates
Test case templates are tools that provide a structured approach to documenting, managing, and executing test cases. They ensure consistency, improve efficiency, and align testing efforts with your organization’s standards and requirements.
TestRail offers flexible test case templates that can be reused across various projects and test suites. These templates can also be customized to fit specific testing methodologies and project requirements, making TestRail a powerful and adaptable tool for maintaining organization throughout the testing process.
Here are the four default test case templates in TestRail that you can customize to suit your needs:
- Test Case (Text):
Image: This flexible template allows users to describe the steps testers should take to test a given case more fluidly.
- Test Case (Steps)
Image: This template allows you to add individual result statuses to each step of your test, as well as links to defects, requirements, or other external entities for each step. This distinction provides you with greater visibility, structure, and traceability.
- Exploratory Session
Image: TestRail’s Exploratory Session template uses text fields where you can define your Mission and Goals, which will guide you through your exploratory testing session.
- Behavior Driven Development (BDD)
Image: This template allows you to design and execute your BDD scenarios directly within TestRail. Users can also define tests as scenarios. Scenarios in BDD typically follow the Given-When-Then (GWT) format.
By using these test case templates, you can create a standardized format that simplifies the creation, execution, and analysis of test cases. This consistency ensures that all necessary information on test scenarios and procedures is well-documented, contributing to a more efficient and organized testing process.
To dive deeper into how TestRail can help you streamline your testing processes—from test case design to execution—explore our free TestRail Academy course, Fundamentals of Testing with TestRail.
Test case writing best practices
Writing effective test cases is vital to maintaining high-quality software. Here are key best practices to consider when developing your test cases:
1. Prioritize your test cases
Start by prioritizing test cases based on their importance and potential impact on the software. Utilizing a priority system will help you identify which test cases should be written and executed first. Consider techniques like:
- Risk-based prioritization
- History-based prioritization
- Coverage-based prioritization
- Version-based prioritization
- Cost-based prioritization
For instance, in an e-commerce application, a test case that verifies the correct calculation of sales tax might be more critical—and higher in priority—than one that checks the color of a button.
2. Make test cases clear and easy to understand
Your test cases should be concise and straightforward, ensuring that anyone on the testing team can easily understand what the test aims to achieve.
Enhance clarity by including attachments, screenshots, or recordings where necessary. For example, if you’re testing login functionality, your test case should clearly state the steps, the credentials to use, and the expected outcome, such as successfully displaying the user dashboard.
Also, make sure your test case names are intuitive and easy to reference. An effective naming convention is crucial, especially when managing thousands of test cases.
When naming a test case related to reusable objects, consider incorporating that information in the title. Additionally, document preconditions, attachments, and test environment data in the test case description.
3. Specify expected results
Clearly defined expected results are crucial for ensuring your tests are executed correctly and that your software performs as anticipated. They serve as a benchmark for comparing actual outcomes.
For example, if you’re testing a shopping cart feature, the expected result might specify that the selected item is successfully added to the cart and that the cart displays the correct price.
4. Cover both happy and unhappy paths
To maximize software requirement coverage, write test cases that account for various scenarios.
Happy paths refer to the common actions users typically take. In contrast, unhappy paths represent scenarios where users behave unexpectedly. Covering these scenarios ensures proper error handling and prevents users from accidentally breaking your software.
For example, in an e-commerce site’s search function, a happy path might involve successfully finding a specific product. An unhappy path might involve searching for a non-existent product and verifying that the appropriate error message is displayed.
5. Regularly review and update test cases
Consistently review and refine your test cases with your team. As the product evolves, test cases must be updated to reflect changes in requirements or functionality. This is especially important for products undergoing significant changes, such as new features or enhancements.
Peer reviews can also be helpful for identifying gaps, inconsistencies, or errors in your test cases, ensuring they meet the required standards.
For instance, if an e-commerce website changes its payment gateway provider, it’s crucial to review and update existing test cases to ensure they still cover all necessary scenarios with the new provider.
Image: TestRail’s intuitive interface makes it easy for you to write and organize your test cases by simply inputting preconditions, test instructions, expected results, priority, and effort estimates of your test case.
Effective test case writing and management are essential to successful software testing. By following best practices and using a dedicated test case management tool like TestRail, you can achieve the level of organization and detail needed to deliver quality software. TestRail’s customizable and reusable test case templates also provide a pre-defined format for documenting test cases, making it easier to create, execute, and analyze tests.
This level of flexibility and visibility into your testing process makes TestRail an easy fit into any organization’s test plan — Try TestRail for free to see how it can help with your test planning.
Test Cases: FAQS
Benefits of test cases
Test cases offer several benefits, aligning with the Agile methodology’s principles of flexibility, collaboration, and responsiveness to change. Here are the key benefits:
- Shared understanding: Test cases provide a clear and documented set of requirements and acceptance criteria for user stories or features. This ensures that the entire team, including developers, testers, and product owners, has a shared understanding of what needs to be tested.
- Efficiency: With predefined test cases, testing becomes more efficient. Software testers don’t have to decide what to test or how to test it each time. They can follow the established test cases, saving time and effort.
- Regression Testing: Agile development involves frequent code changes. Test cases help ensure that new code changes do not introduce regressions by providing a structured set of tests to run after each change.
- Reusability: Test cases can be reused across sprints or projects, especially if they cover common scenarios. This reusability promotes consistency and saves time when testing similar functionality.
- Traceability: Test cases create traceability between user stories, requirements, and test execution. This traceability helps ensure that all requirements are tested and provides transparency in reporting.
- Documentation: Test cases serve as test documentation for testing efforts. They capture testing scenarios, steps, and expected outcomes, making it easier to track progress and demonstrate compliance with requirements.
- Adaptability and faster feedback: Agile emphasizes early and continuous testing and teams often need to respond to changing requirements and priorities. Test cases help identify issues and defects in the early stages of the software development lifecycle and can be updated or created on the fly for quicker feedback and corrective action.
- Continuous improvement: Agile encourages a culture of continuous improvement. Test cases and test results provide valuable data for retrospectives, helping teams identify areas for enhancement in their testing processes.
- Customer satisfaction: Effective testing leads to higher software quality and better user experiences. Well-documented test cases contribute to delivering a product that meets or exceeds customer expectations.
When written and used properly, test cases can foster collaboration, accelerate testing cycles, and enhance the overall quality of software products ultimately enabling your team to deliver quality software in an iterative and customer-oriented manner.
Test cases for different software testing approaches
Different software testing approaches may require distinct types of test cases to address specific testing objectives. Here’s a breakdown of common types of test cases associated with different software testing approaches:
| Testing Approach | Types of Test Cases | Description |
| Functional Testing | Unit Test Cases | Test individual functions or methods in isolation to ensure they work as expected. |
| Integration Test Cases | Verify that different components or modules work together correctly when integrated. | |
| System Test Cases | Test the entire system or application to validate that it meets the specified functional requirements. | |
| User Acceptance Test (UAT) Cases | Involve end-users or stakeholders to ensure that the system meets their needs and expectations. | |
| Non-Functional Testing | Performance Test Cases | Measure aspects like speed, responsiveness, scalability, and stability. |
| Load Test Cases | Assess how the system performs under specific load conditions, such as concurrent users or data loads. | |
| Stress Test Cases | Push the system to its limits to identify failure points and performance bottlenecks. | |
| Security Test Cases | Evaluate the system’s security measures and vulnerabilities. | |
| Usability Test Cases | Assess the user-friendliness, intuitiveness, and overall user experience of the software. | |
| Accessibility Test Cases | Ensure that the software is usable by individuals with disabilities, complying with accessibility standards. | |
| Regression Testing | Regression Test Cases | Verify that new code changes or updates do not negatively impact existing functionalities. |
| Smoke Test Cases | Execute a subset of essential test cases to quickly assess whether the software build is stable enough for further testing. | |
| Exploratory Testing | Exploratory Test Cases | Testers explore the software without predefined scripts, identifying defects and issues based on intuition and experience. |
| Compatibility Testing | Browser Compatibility Test Cases | Test the software’s compatibility with different web browsers and versions. |
| Device Compatibility Test Cases | Assess the software’s performance on various devices (desktop, mobile, tablets) and screen sizes. | |
| Integration Testing | Top-Down Test Cases | Begin testing from the top level of the application’s hierarchy and gradually integrate lower-level components. |
| Bottom-Up Test Cases | Start testing from the lower-level components and integrate them into higher-level modules. | |
| Acceptance Testing | Alpha Testing Cases | Conducted by the internal development team or a specialized testing team within the organization. |
| Beta Testing Cases | Involves external users or a select group of customers to test the software in real-world scenarios. | |
| Load and Performance Testing | Load Test Cases | Simulate a specified number of concurrent users or transactions to assess the software’s performance under typical load conditions. |
| Usability Test Cases | Evaluate touch gestures, screen transitions, and overall user experience. |
Common mistakes to avoid when writing test cases
Writing effective test cases is crucial for successful software testing. To ensure your test cases are useful and efficient, it’s important to avoid common mistakes. Here are some of the most common mistakes to watch out for:
- Unclear objectives: Ensure that each test case has a clear and specific objective, outlining what you are trying to test and achieve.
- Incomplete test coverage: Don’t miss critical scenarios. Ensure your test cases cover a wide range of inputs, conditions, and edge cases.
- Overly complex test cases: Keep test cases simple, focusing on testing one specific aspect or scenario to maintain clarity.
- Lack of independence: Avoid dependencies between test cases, as they can make it challenging to isolate and identify issues.
- Poorly defined preconditions: Clearly specify preconditions that must be met before executing a test case to ensure consistent results.
- Assuming prior knowledge: Write test cases in a way that is understandable to anyone, even new team members unfamiliar with the system.
- Ignoring negative scenarios: Test not only positive cases but also negative scenarios, including invalid inputs and error handling
Advanced Tips for Experienced Testers
For seasoned testers aiming to enhance their testing strategies, consider these advanced tips:
1. Embrace data-driven testing
Data-driven testing (DDT) involves executing the same test case with multiple sets of data. This technique is beneficial for validating various inputs, especially when using test automation tools like Selenium. Create a structured test case format that allows for easy integration of different data sets, ensuring comprehensive coverage.
2. Leverage test case reusability
Design test cases with reusability in mind. Modular test cases, identifiable by unique test case IDs, can be reused across different test scenarios. For example, a UI test case that verifies login functionality can be adapted for different user roles or security scenarios, improving efficiency in both manual and automated testing.
3. Apply behavior-driven development (BDD) techniques
Behavior-Driven Development focuses on the end user’s perspective. Use the Given-When-Then format to write functional test cases that mirror real-world use cases. This approach aligns test cases with user requirements and fosters better collaboration between stakeholders.
4. Utilize test case management tools effectively
Advanced test case management tools, like TestRail, offer more than basic tracking. Explore features such as custom fields, detailed reporting, and integration with tools like Selenium for test automation. These functionalities can provide deeper insights and streamline the management of both manual and automated tests.
5. Implement test automation strategically
Automate repetitive and high-impact test cases to enhance efficiency. Focus on automating test cases that offer the most value, such as regression tests or critical user interface (UI) tests. Ensure your automated tests are well-maintained and updated in line with application changes.
6. Use risk-based testing
Prioritize your test cases based on risk. Identify which features or components pose the highest risk and ensure they are thoroughly tested. For instance, in an e-commerce application, a functional test case that verifies the correct calculation of sales tax may be more critical than a test case for button color.
Metrics and KPIs for test case management
Monitoring the effectiveness of your test case management is essential. Here are key metrics and KPIs to track:
1. Test case coverage
- Definition: The percentage of requirements covered by test cases.
- Why it matters: Ensures comprehensive testing of all software features.
- How to measure: Divide the number of test case IDs linked to requirements by the total number of requirements and multiply by 100.
2. Pass/fail rate
- Definition: The ratio of passed test cases to failed test cases.
- Why it matters: Provides insights into software stability and quality assurance.
- How to measure: Divide the number of passed test cases by the total number of executed test cases and multiply by 100.
3. Defect density
- Definition: The number of defects found per unit of software size (e.g., per thousand lines of code).
- Why it matters: Indicates software quality and the effectiveness of your testing efforts.
- How to measure: Divide the total number of defects identified by the size of the software and multiply by 1,000.
4. Test execution time
- Definition: The average time required to execute a test case.
- Why it matters: Helps assess testing efficiency and identify potential bottlenecks.
- How to measure: Record the time for each test case execution and calculate the average.
5. Test case effectiveness
- Definition: The ratio of defects detected by test cases compared to the total number of defects found.
- Why it matters: Shows how well test cases identify issues.
- How to measure: Divide the number of defects found by test cases by the total number of defects found and multiply by 100.
6. Test case maintenance ratio
- Definition: The ratio of test cases updated or created to the total number of test cases.
- Why it matters: Reflects how frequently test cases are revised to keep pace with changes.
- How to measure: Divide the number of updated or new test cases by the total number of test cases and multiply by 100.
7. Test automation ROI
How to measure: Compare the costs of test automation tools and maintenance with the benefits, such as time saved and improved quality.
Definition: The return on investment for test automation efforts.
Why it matters: Assesses the value derived from automating test cases versus the cost.
