early-return-from-functions

name	early-return-from-functions
description	Use early returns to reduce nesting and clarify control flow. Use when simplifying conditionals or guard clauses.

Early Return from Functions

Return early when result is determined to skip unnecessary processing.

Incorrect (processes all items even after finding answer):

function validateUsers(users: User[]) {
  let hasError = false;
  let errorMessage = '';

  for (const user of users) {
    if (!user.email) {
      hasError = true;
      errorMessage = 'Email required';
    }
    if (!user.name) {
      hasError = true;
      errorMessage = 'Name required';
    }
    // Continues checking all users even after error found
  }

  return hasError ? { valid: false, error: errorMessage } : { valid: true };
}

Correct (returns immediately on first error):

function validateUsers(users: User[]) {
  for (const user of users) {
    if (!user.email) {
      return { valid: false, error: 'Email required' };
    }
    if (!user.name) {
      return { valid: false, error: 'Name required' };
    }
  }

  return { valid: true };
}