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Cover image for The Most Dangerous Bug Is the One That Doesn’t Crash
Hisham Idris
Hisham Idris

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The Most Dangerous Bug Is the One That Doesn’t Crash

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.

Here is a real example:
order.status = "paid";
order.invoiceId = null;

No crash.
No error.
Completely broken state.

With a runtime invariant:

invariant("order.status === 'paid' -> order.invoiceId != null");

This fails immediately — exactly when the logic breaks.
Not days later. Not in production.

GitHub repository:
https://github.com/vortexshadow678-hash/invariant-guard

Top comments (3)

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Hisham Idris

I built this mainly to catch logic bugs as early as possible,
before they silently spread through the app.

It’s lightweight, easy to try, and doesn’t change how you write React code.
If you’ve ever debugged a “nothing crashed but everything is wrong” bug,
this might be worth experimenting with.

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Hisham Idris

One thing I keep noticing is that these bugs aren’t obvious at the point of change.

Each update looks reasonable on its own, but the assumptions only break after a few steps.

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Hisham Idris

just try it you will never loss anything