Configuration Testing
Configuration Testing is the process of verifying application behavior under different configuration settings to ensure the system works correctly across environment variables, feature flags, settings, and integrations.
Configuration testing answers: “Does the application behave correctly with different configurations?”
1. Definition
Configuration Testing is the process of verifying application behavior under different configuration settings to ensure the system works correctly across environment variables, feature flags, settings, and integrations.
2. Purpose of Configuration Testing
- Ensure application stability across environments
- Validate environment-specific settings
- Detect misconfiguration issues early
- Prevent production failures due to config errors
3. What Is a Configuration (Tester’s View)
A configuration includes:
- Environment variables
- Feature flags / toggles
- Application settings
- URLs and endpoints
- Timeouts and limits
- Role-based access settings
4. Common Configuration Areas to Test
4.1 Environment-Specific Settings
- Dev / QA / UAT / Prod differences
- API endpoints
- Database connections
4.2 Feature Flags
- Feature ON vs OFF behavior
- Partial rollout behavior
- Default state validation
4.3 Application Properties
- Session timeout values
- File size limits
- Retry counts
4.4 Integration Configuration
- Third-party service URLs
- Authentication keys (masked)
- Callback endpoints
4.5 Role & Permission Configuration
- User roles
- Access control rules
- Feature visibility by role
5. Manual Tester’s Role
- Understand configurable parameters
- Validate behavior for each configuration
- Verify default configurations
- Identify config-related failures
- Distinguish config issues from code defects
6. Configuration Testing vs Compatibility Testing
| Aspect | Configuration Testing | Compatibility Testing |
|---|---|---|
| Focus | Settings & flags | Platforms & browsers |
| Cause of failure | Misconfiguration | Platform differences |
7. Real-Time Examples
Example 1: Feature Flag
- Discount feature OFF → Discount not shown
- Discount feature ON → Discount applied correctly
Example 2: Timeout Configuration
- Session timeout = 10 mins → Auto logout after inactivity
8. Common Defects Found
- Feature enabled but partially working
- Incorrect default configurations
- Environment mismatch (QA vs Prod)
- Integration failures due to wrong endpoints
9. Best Practices
- Maintain a configuration checklist
- Validate defaults first
- Test high-risk configurations first (risk-based)
- Coordinate with DevOps/Release teams
- Document tested configurations
10. Common Mistakes
- Assuming configurations are correct
- Testing only default settings
- Ignoring feature flag combinations
- Logging config issues as application bugs
11. Interview-Ready Answers
Short answer:
Configuration testing verifies application behavior under different configuration settings.
Detailed answer:
Configuration testing ensures the application works correctly with various environment settings, feature flags, and configurations, preventing failures caused by misconfiguration.
12. Key Takeaway
Configuration Testing protects releases from silent failures caused by wrong settings, which are among the most common production issues.