The Most Dangerous Bug Is the One That Doesn’t Crash
Published: (January 17, 2026 at 05:14 PM EST)
1 min read
Source: Dev.to
Source: Dev.to
The Problem
Bugs that crash your app are easy to notice.
The dangerous ones keep running… silently. They pass tests, types, and reviews — and still corrupt your logic.
Example
order.status = "paid";
order.invoiceId = null;No crash. No error. Completely broken state.
Solution with Runtime Invariant
invariant("order.status === 'paid' -> order.invoiceId != null");This fails immediately — exactly when the logic breaks, not days later and not in production.