eslint/default-param-last Style
What it does
Requires default parameters in functions to be the last ones.
Why is this bad?
Placing default parameters last allows function calls to omit optional trailing arguments, which improves readability and consistency. This rule applies equally to JavaScript and TypeScript functions.
Examples
Examples of incorrect code for this rule:
js
/* default-param-last: "error" */
function f(a = 0, b) {}
function f(a, b = 0, c) {}
function createUser(isAdmin = false, id) {}
createUser(undefined, "tabby");Examples of correct code for this rule:
js
/* default-param-last: "error" */
function f(a, b = 0) {}
function f(a = 0, b = 0) {}
function createUser(id, isAdmin = false) {}
createUser("tabby");Examples of incorrect TypeScript code for this rule:
ts
/* default-param-last: "error" */
function greet(message: string = "Hello", name: string) {}
function combine(a: number = 1, b: number, c: number) {}
function combine(a: number, b: number = 2, c: number) {}
function combine(a: number = 1, b?: number, c: number) {}Examples of correct TypeScript code for this rule:
ts
/* default-param-last: "error" */
function greet(name: string, message: string = "Hello") {}
function combine(a: number, b: number = 2, c: number = 3) {}
function combine(a: number, b?: number, c: number = 3) {}How to use
To enable this rule using the config file or in the CLI, you can use:
json
{
"rules": {
"default-param-last": "error"
}
}ts
import { defineConfig } from "oxlint";
export default defineConfig({
rules: {
"default-param-last": "error",
},
});bash
oxlint --deny default-param-lastVersion
This rule was added in v0.2.15.