How do you write test cases that cover all the requirements and scenarios?

1 Understand the requirements

The first step to writing test cases is to understand the requirements of the software. Requirements are the descriptions of what the software should do, and how it should behave under different conditions. They can be written in various formats, such as user stories, use cases, or functional specifications. You should review the requirements carefully, and ask questions or clarify any ambiguities with the product owner, developer, or business analyst. You should also identify the scope, priority, and risks of each requirement, and how they relate to the overall goals of the project.

2 Design the test scenarios

The next step is to design the test scenarios that will cover the requirements. Test scenarios are the high-level descriptions of how to test a requirement, and what outcomes to verify. They can be based on the normal, alternative, or exceptional flows of the software, and they should include both positive and negative cases. You should consider the different inputs, outputs, preconditions, postconditions, and dependencies of each scenario, and how they affect the functionality and performance of the software. You should also use techniques such as boundary value analysis, equivalence partitioning, or decision tables to generate more test scenarios.

3 Write the test cases

The final step is to create test cases that will execute the test scenarios. Test cases are detailed instructions for carrying out tests and comparing the results with the expected results. They should be written in a clear, concise, and consistent language, and follow a standard format or template. Each test case should include a unique identifier (e.g. a number or name), a brief summary of what it is testing and why, numbered steps to perform the test, specific values/inputs to use, expected outcomes/outputs, actual outcomes/outputs, status of the test (e.g. pass/fail/blocked), and any additional information or observations about the test. It's also recommended to use tools such as spreadsheets, word processors, or test management software to organize, document, and track your test cases.

4 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?