classMethodsThis

Reports class methods that do not use this.

✅ This rule is included in the ts stylistic presets.

Class methods that don’t use this are often better suited as static methods or standalone functions. Instance methods that don’t access instance state can be misleading and suggest a design issue.

Examples

❌ Incorrect

class Calculator {
  add(a: number, b: number) {
    return a + b;
  }
}

class Formatter {
  format(value: string) {
    return value.trim().toLowerCase();
  }
}

class Handler {
  get type() {
    return "default";
  }
}

class Processor {
  handler = () => {
    return Math.random();
  };
}

✅ Correct

class Calculator {
  add(a: number, b: number) {
    return this.precision(a + b);
  }
}

class Calculator {
  static add(a: number, b: number) {
    return a + b;
  }
}

function add(a: number, b: number) {
  return a + b;
}

class Counter {
  private count = 0;

  get value() {
    return this.count;
  }
}

class Base {
  method(): void {}
}

class Derived extends Base {
  override method() {
    console.log("overridden");
  }
}

interface Handler {
  handle(): void;
}

class MyHandler implements Handler {
  handle() {
    console.log("handled");
  }
}

Options

This rule is not configurable.

When Not To Use It

If your codebase has many classes that implement external interfaces or extend base classes where methods are expected to exist without using this, this rule may produce false positives. Some frameworks require instance methods for dependency injection or other patterns even when they don’t use this.

Further Reading

• MDN: Classes
• MDN: static

Equivalents in Other Linters

• ESLint: class-methods-use-this@typescript-eslint/class-methods-use-this