AI Code Smells: 15 Red Flags That Scream 'This Was Generated'

1. The "Explicit" Boolean Check

AI models are often overly verbose to avoid ambiguity.

// AI Smell
if (user.isValid === true) { ... }

// Human
if (user.isValid) { ... }

2. The "Tutorial" Variable Names

Seeing `foo`, `bar`, or `baz` in production code? That's an LLM hallucinating a tutorial context.

3. The "Zombie" Code

Blocks of commented-out code that look like alternative implementations. AI often leaves its "drafts" behind.

4. The "One-Size-Fits-All" Error Log

Generic error handling that gives you zero context.

catch (error) {
  console.error("An error occurred:", error); // Thanks, helpful.
}

5. The "Regurgitated" Documentation

Comments that sound like they were copied straight from MDN.

// The map() method creates a new array populated with the results...
const newArray = array.map(...);

6. The "Over-Defensive" Null Check

Checking for existence three levels deep when the type system already guarantees it.

if (data && data.user && data.user.profile && data.user.profile.id) { ... }

7. The "Premature" Optimization

Implementing complex caching or memoization for a simple function that runs once.

8. The "Ghost" Variable

Variables that are declared, assigned, but never actually used. A sign of a refactor that the AI forgot to finish.

9. The "Copy-Paste" Repetition

Repeating the same logic 3 times instead of writing a loop or a helper function.

10. The "Over-Engineered" Class

Creating a `UserProcessor` class with a constructor and one method, instead of just a function.

11. The "Default" Switch Case

Handling a `default` case that throws an error, even when all enum values are covered.

12. The "Magic" Number

Using `86400000` directly in code instead of `const DAY_IN_MS = 86400000`.

13. The "Unused" Import

Importing `useEffect` but never using it. AI often hallucinates requirements.

14. The "Generic" TODO

`// TODO: Implement error handling` - The AI knows it should be there, but was too lazy to write it.

15. The "Soulless" Formatting

As always, the "Wall of Text" effect. No breathing room, no rhythm.