What Are Linters and Formatters in Development

Short answer

Linters analyze code for potential errors and style violations. Formatters automatically rewrite code to follow a consistent style without changing logic.

How it works

• Linters like ESLint and Pylint use static analysis to find bugs and enforce rules.
• Formatters like Prettier and Black parse code into an AST and print it with consistent spacing.

Example

An ESLint config:

{
  "extends": "eslint:recommended",
  "rules": {
    "semi": ["error", "always"]
  }
}

Why it matters

Consistent code style reduces cognitive load in code reviews. Linters catch common mistakes like unused variables or missing dependencies before they reach production.