no-instance-methods-without-this

Report instance methods that never use this or super.

Rule details Problem

This rule checks non-static class methods with kind: "method". Getters, setters, constructors, and static methods are ignored.

By default it checks public, protected, and private methods. If a method body never touches this or super, the rule reports it.

The scan walks the whole method body, including nested functions. If a nested callback uses this, the method is treated as using this too.

Why this exists

The rule is aimed at roblox-ts, where extra instance methods add metatable overhead. If a method is really a helper, keeping it at module scope is often a better fit.

Options

All three options default to true.

• checkPublic
• checkProtected
• checkPrivate

eslint.config.ts

import plugin from "eslint-plugin-cease-nonsense";

export default [
  {
    plugins: { "cease-nonsense": plugin },
    rules: {
      "cease-nonsense/no-instance-methods-without-this": [
        "error",
        { checkPrivate: false, checkProtected: true, checkPublic: true },
      ],
    },
  },
];

Examples

Incorrect

class MathSystem {
  private calculate(x: number): number {
    return x * x;
  }
}

Correct

function calculate(x: number): number {
  return x * x;
}

class MathSystem {
  public run(value: number): number {
    return calculate(value);
  }

  protected log(): void {
    print(this);
  }
}

Related rules

require-module-level-instantiation Another rule that pushes reusable logic toward module scope.