How to Write Test Cases

What is a Test Case?

A test case is a documented set of steps, data and expected results used to verify one behaviour. Test Scenario is the what (verify login); Test Case is the how (steps with data).

Test Case Template

ID: TC_LOGIN_001
Title: Valid user can log in
Preconditions: user registered, on /login
Steps: 1. Enter email 2. Enter password 3. Click Login
Data: user@test.com / Pass@123
Expected: redirect to /dashboard, welcome banner shown
Severity: Critical | Priority: High

Good Test Case Habits

• One behaviour per case, independent and repeatable.
• Use real representative data, plus one negative case per field.
• Name expected results exactly (text, URL, status code).
• Keep steps atomic so anyone can execute them.

Test Data

Prepare valid, invalid, boundary and empty data sets. Mask PII; refresh data between runs so tests never depend on execution order.

Key Points

• Scenario groups cases; cases prove behaviour.
• A case without expected results is just exploration notes.
• Negative cases find more bugs than happy paths.