Code Smell 274 - Cascaded Returns

by Maximiliano ContieriOctober 10th, 2024

Too Long; Didn't Read

Prevent chaining return statements for better code readability and flow.

featured image - Code Smell 274 - Cascaded Returns

Stop the Return Roller-coaster

TL;DR: Prevent chaining return statements for better code readability and flow.

Problems

Confusing flow
Debugging Difficulty
Buried logic
Low readability
Risk of errors
Overuse of IF Sentences

Solutions

Early return
Clear conditions
Use guard clauses
Replace IFs with Polymorphism

Refactorings

Context

When you chain multiple return statements within a function, you create a confusing flow. This leads to spaghetti code where understanding the exit points becomes hard. Cascaded returns can hide important logic deep within the function, making it harder to follow and debug. You read through multiple branches to determine when and where the function ends.

Sample Code

Wrong

function discount(price, isMember) {
  if (price < 20) {
    if (isMember) {
      return 5;
    } else {
      return 2;
    }
  } else {
    if (isMember) {
      return 10;
    } else {
      return 0;
    }
  }
}

Right

class Member {
  discount(price) {
    return price < 20 ? 5 : 10;
    // This ternary is an essential IF
    // And you should NOT remove it
  }
}

class NonMember {
  discount(price) {
    return price < 20 ? 2 : 0;
    // This ternary is an essential IF
    // And you should NOT remove it
  }
}

function discount(price, status) {
  return status.discount(price);
}

const member = new Member();
const nonMember = new NonMember();

Detection

[x]Automatic

You can spot cascaded returns by looking for multiple nested return statements. If you see deep indentation or many layers of conditions, that's a sign of this code smell.

Level

[X ] Beginner

AI Generation

AI generators might create this smell when tasked with solving complex problems quickly. Cascaded returns often happen when the generator handles multiple conditions without optimizing the flow.

AI Detection

With clear instructions, AI tools can avoid cascaded returns. You can ask the AI to use guard clauses, polymorphism and simplify returns for a cleaner solution.

Try Them!

Remember: AI Assistants make lots of mistakes

Without Proper Instructions	With Specific Instructions

Conclusion

Avoid cascaded returns to make your code more readable, maintainable, and easier to debug. Stick to early returns and guard clauses to prevent unnecessary complexity.