🔁 DRY — is good, but not always: when duplication saves the project

We’ve all had it drilled into us: Don’t Repeat Yourself!
Duplication is evil, they say, and all code must be reused.

The idea is valid. But like every principle in development, it doesn’t work every time.

On one project, we built a universal popup component.
We wanted it to work for every scenario: login, confirmation, errors, settings, invites, and more.

At first, everything was great. DRY. One component. Convenient. Elegant.

But over time it grew:

30+ props
nested if/else statements
dozens of states
custom renders for various cases

At some point, this component became a 1000+ line file.
Testing became hard. Maintaining — terrifying. Using it — confusing.

💡 What should we have done?

We realized it would’ve been easier to create three separate components:

<LoginPopup />
<InvitePopup />
<ErrorPopup />

They would’ve been 80% identical, but:

Their names clearly indicated their purpose
Internal logic was linear and predictable
Easier to maintain, easier to read
No need to remember which props to pass

🤯 Why DRY can be harmful

DRY works well within the same layer (UI, logic, styles).
But mixing layers just to reuse code leads to pain.
DRY creates abstractions, and they only work if changes happen in sync.
When components serve different scenarios, merging them leads to flags and exceptions.
Abstractions can become so universal, no one but the author dares touch them.

✅ Where DRY works well

Utilities: formatDate, getAgeFromDate, truncateText
Styles: shared buttons, spacing, fonts
Business logic with consistent operations

⚠️ Where DRY can backfire

UI components with different semantics and context
Merging multiple scenarios into one function
Trying to reuse what would be simpler to copy

🧠 What to remember

DRY isn’t a law. It’s a guideline.
Sometimes code duplication means readability and simplicity.

Three clear components are better than one universal monster.

🔚 Conclusion

Write code your future self and your team can read.
If that means repeating a few lines — so be it.

🤘 Don’t listen to dogma. Use your brain.
Sometimes DRY is hell. And sometimes — salvation.
Learn to feel the difference.

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