#max-params

#Configuration

import { defineConfig, ts } from '@rslint/core';

export default defineConfig([
  ts.configs.recommended,
  {
    rules: {
      '@typescript-eslint/max-params': 'error',
    },
  },
]);

Enforce a maximum number of parameters in function definitions.

#Rule Details

Functions that take many parameters are usually harder to read and maintain than functions that take fewer. This rule reports any function whose parameter list exceeds the configured maximum (default 3).

The typescript-eslint variant adds the countVoidThis option for the TypeScript this: void parameter, which is a type annotation rather than a real argument. By default, this: void is excluded from the parameter count.

Examples of incorrect code for this rule:

function foo(a, b, c, d) {}

const bar = (a, b, c, d) => {};

class Foo {
  method(this: Foo, a, b, c) {}
}

Examples of correct code for this rule:

function foo(a, b, c) {}

const bar = (a, b, c) => {};

class Foo {
  method(this: void, a, b, c) {}
}

#Options

The rule accepts an options object:

{ "@typescript-eslint/max-params": ["error", { "max": 3 }] }

• max (default 3): the maximum number of parameters allowed.
• maximum: deprecated alias for max.
• countVoidThis (default false): if true, count a this: void parameter toward the limit.

Examples of incorrect code with { "max": 2 }:

{ "@typescript-eslint/max-params": ["error", { "max": 2 }] }

function foo(a, b, c) {}

Examples of correct code with { "max": 2 }:

{ "@typescript-eslint/max-params": ["error", { "max": 2 }] }

function foo(a, b) {}

Examples of incorrect code with { "countVoidThis": true, "max": 2 }:

{ "@typescript-eslint/max-params": ["error", { "countVoidThis": true, "max": 2 }] }

class Foo {
  method(this: void, a, b) {}
}

#Original Documentation

• @typescript-eslint/max-params
• max-params (ESLint core)