#default-param-last

#Configuration

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

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

#Rule Details

Enforce default parameters to be last. This is the TypeScript-enhanced version of the ESLint default-param-last rule. It also handles TypeScript-specific optional parameters (those with a ? modifier), enforcing that they come after required parameters.

Putting default and optional parameters last makes function calls clearer, since callers do not need to pass undefined to skip optional arguments.

Examples of incorrect code for this rule:

function foo(a = 1, b: number) {}

function bar(a?: string, b: number) {}

class MyClass {
  method(a = 0, b: string) {}
}

Examples of correct code for this rule:

function foo(a: number, b = 1) {}

function bar(a: number, b?: string) {}

function baz(a: number, b = 1, ...rest: number[]) {}

#Original Documentation

• typescript-eslint default-param-last