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eslint/max-params Style

What it does

Enforce a maximum number of parameters in function definitions which by default is three.

Why is this bad?

Functions that take numerous parameters can be difficult to read and write because it requires the memorization of what each parameter is, its type, and the order they should appear in. As a result, many coders adhere to a convention that caps the number of parameters a function can take.

Examples

Examples of incorrect code for this rule:

function foo(bar, baz, qux, qxx) {
  doSomething();
}

let foo = (bar, baz, qux, qxx) => {
  doSomething();
};

Examples of correct code for this rule:

function foo(bar, baz, qux) {
  doSomething();
}

let foo = (bar, baz, qux) => {
  doSomething();
};

Configuration

countThis

type: "always" | "never" | "except-void"

This option controls when to count a this parameter.

• "always": always count this
• "never": never count this
• "except-void": count this only when it is not type void

countVoidThis

type: boolean

default: false

Deprecated alias for countThis.

For example { "countVoidThis": true } would mean that having a function take a this parameter of type void is counted towards the maximum number of parameters.

max

type: integer

default: 3

Maximum number of parameters allowed in function definitions.

How to use

To enable this rule using the config file or in the CLI, you can use:

Config (.oxlintrc.json)

{
  "rules": {
    "max-params": "error"
  }
}

Config (oxlint.config.ts)

import { defineConfig } from "oxlint";

export default defineConfig({
  rules: {
    "max-params": "error",
  },
});

CLI

oxlint --deny max-params

Version

This rule was added in v0.2.14.

References

• Rule Source
• Upstream rule docs
• Open rule in Oxc Playground