Testing is More Art Than Science

Despite what the metrics tell you, good testing is about intuition, experience, and creativity—not just coverage percentages.

The Science Part

Yes, testing has scientific elements:

• Repeatability: Tests should give consistent results
• Measurement: Coverage metrics and performance benchmarks
• Methodology: Systematic approaches to finding bugs

The Art Part

But the best testing comes from:

• Intuition: Knowing where bugs are likely to hide
• Creativity: Thinking of edge cases others miss
• Experience: Understanding how systems fail in practice

Why Coverage Isn't Everything

The Coverage Trap

100% code coverage doesn't mean 100% confidence in your code.

Testing the Wrong Things

You can have perfect coverage of the wrong behavior.

Missing Integration Points

Unit tests don't catch how components interact.

The Artistic Elements

Designing Test Cases

Good test cases tell a story about how the system should behave.

Choosing What to Test

Not everything needs the same level of testing. Some code is more critical than others.

Understanding User Behavior

The best tests reflect how users actually use the system.

The Craftsperson's Approach

Start with Risk

Test the things that would hurt most if they broke.

Think Like an Attacker

What would someone do to break this system?

Consider the User Journey

How does this feature fit into the broader user experience?

Embrace Uncertainty

Testing is about exploring unknowns, not just verifying knowns.

Practical Wisdom

1. Test Behavior, Not Implementation: Focus on what the system does, not how it does it
2. Write Tests That Fail Well: Good test failures tell you exactly what went wrong
3. Balance Unit and Integration Tests: Both have their place
4. Automate the Boring Stuff: Save human creativity for the hard problems

The Bottom Line

Metrics can guide you, but they can't replace judgment. The best testing combines systematic approaches with creative thinking.

Trust your instincts. If something feels fragile, it probably is.