Code Smell 304: Null Pointer Exception - How to Avoid NULL References That Cause Runtime Crashes

I keep writing about NULL problems, yet every day the news reminds me: NULL is still alive and kicking.

TL;DR: Avoid NULL references that cause runtime crashes by using proper validation and null-safe patterns

Problems 😔

• Runtime crashes
• Big incidents and outages
• Unpredictable behavior
• Hard debugging
• User frustration
• System instability
• Poor reliability

In Google Cloud case:

• Poor error handling: The code crashed instead of gracefully handling null data
• No feature flags: New code wasn't gradually rolled out with safety controls
• Instant global replication: Bad data spreads worldwide immediately like in Crowdstrike Incident
• No randomized backoff: Recovery caused infrastructure overload
• Inadequate testing: The failure scenario was never tested during deployment

Solutions 😃

1. Avoid nulls
2. Use null checks if nulls are beyond your control (for example, an external API)
3. Initialize default values
4. Implement guard clauses
5. Use null objects
6. Don't use optionals

Refactorings ⚙️

https://hackernoon.com ...