Code Clone

ID: code_clone | Severity: Medium (default)

This detector identifies duplicated code blocks across your project. It uses AST-based tokenization to find exact matches while ignoring differences in formatting and comments.

Why this is a smell

• Maintenance Overhead: Fixing a bug or making a change in one place requires updating all duplicates.
• Violation of DRY: Duplication is a clear sign that abstraction or reuse is missing.
• Inconsistent Evolution: Over time, duplicates may drift apart, leading to subtle bugs and harder refactoring.

How to fix

1. Extract Method: Move the shared logic into a single function and call it from multiple places.
2. Generic Components: For UI code, create a reusable component with props.
3. Utility Modules: Move common helper logic to a shared utility file.

Configuration

rules:
  code_clone:
    enabled: true
    severity: medium
    min_tokens: 50
    min_lines: 6

Options

• min_tokens: The minimum number of normalized tokens to trigger a clone detection (default: 50).
• min_lines: The minimum number of lines the clone must span (default: 6).

ESLint Rule

This detector is available as an ESLint rule for real-time feedback in your editor.

// eslint.config.js
export default [
  {
    rules: {
      '@archlinter/no-code-clone': 'warn',
    },
  },
];

See ESLint Integration for setup instructions.