A comprehensive reference of common edge cases to test. Use this as a checklist when generating tests.

Table of Contents

1. Input Validation Edge Cases
2. Numeric Edge Cases
3. String Edge Cases
4. Date & Time Edge Cases
5. Collection Edge Cases
6. Authentication & Authorization Edge Cases
7. Concurrency Edge Cases
8. Network & API Edge Cases
9. Database Edge Cases
10. File Handling Edge Cases
11. Business Logic Edge Cases
12. UI/UX Edge Cases

Input Validation Edge Cases

Null and Undefined

Test Cases:
✓ null input
✓ undefined input
✓ missing required field
✓ partially filled object
✓ nested null values

Example Prompt:
"Generate tests for null/undefined handling:
 - What happens when input is null?
 - What happens when required fields are missing?
 - How are nested null values handled?"

Common Scenarios:

• validateEmail(null) → should throw or return error
• getUserById(undefined) → should handle gracefully
• { name: 'John', email: null } → should validate email requirement